Update to TypeScript 7

[samreid]

Today, the TypeScript team published this article: https://devblogs.microsoft.com/typescript/progress-on-typescript-7-december-2025/

which says, among other things:

TypeScript’s native previews are fast, stable, and easy to use today – including in your editor.

--incremental and --build mode are also stable and ready to use. So I think we are at a good point to investigate using this for our systems, including but not necessarily limited to:

• Installing @typescript/native-preview in perennial/package.json
• Setting up WebStorm to point to this version, see https://blog.jetbrains.com/webstorm/2025/08/webstorm-2025-2/
• Changing grunt type-check to use tsgo
• Making sure it is compatible with typescript-eslint, see https://github.com/typescript-eslint/typescript-eslint/issues/10940

The main reason this is worth our time is performance. In number-pairs/, grunt type-check --clean currently takes about 20 seconds on my very fast MacBook Pro M4 Pro. The TypeScript team has reported numbers that we could be somewhere around 10x faster. Faster support in the IDE would also be very welcome.

A secondary reason to upgrade is that it is nice to stay up-to-date with changes to important parts of our toolchain.

I'll add to developer meeting to see if there is more to discuss, to estimate the effort here, and to prioritize.

[samreid]

At today's developer meeting, @marlitas asked if I could take the lead on this, and said I could start as soon as I have time. I'll take a look.

[samreid]

Timing numbers from initial experimentation:

Context	Command	Version	Real time (s)
(root)	time grunt type-check --all --clean	5.7	98.34
(root)	time grunt type-check --all --clean	tsgo	25.22
number-pairs	time grunt type-check --clean	5.7	19.82
number-pairs	time grunt type-check --clean	tsgo	8.06
number-pairs	time grunt type-check	5.7	0.66
number-pairs	time grunt type-check	tsgo	0.55

speedup factors are roughly: 4, 2.5 and 1.2

[samreid]

This patch has no type errors. Some cases have a temporary workaround or patch with ts-nocheck or ts-expect-error, many of those will be solved as we port more code to TypeScript. I've been enjoying the improved speed in the IDE and the command line. Every now and then in odd corner cases, I see a disagreement between what the IDE says and what the command line says, despite them pointing to the same version. However, I cannot see any at the moment --maybe they got chased away as I improved coverage and restarted IDE.

It sounds like best practice is for the linter to use a legacy TypeScript version, and that is how we are set up.

It will be a major hassle to maintain BOTH 5.7 and 7.0 type checking, so instead I'd like to coordinate with other developers for when to commit this. At the time a developer pulls the changes, they will need to change their TypeScript settings to point to the native preview as described in https://blog.jetbrains.com/webstorm/2025/08/webstorm-2025-2/#experimental-typescript-go-language-server-support

So I'll stash a many-repo patch here and check in with devs on slack:

IMPORTANT: when committing, probably commit file renames as a separate step to avoid history loss

Details

Subject: [PATCH] Only show the cue when it can be activated, see https://github.com/phetsims/circuit-construction-kit-common/issues/1092
---
Index: phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts b/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts
--- a/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts	(revision f48259a1d221831e2175eb1b3af2fcc8413069b1)
+++ b/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts	(date 1765250763744)
@@ -198,7 +198,6 @@
 
       // Simplified example for the first test case
       class Dog extends PhetioObject {
-        // @ts-expect-error
         public [ attributeName ]: boolean;
 
         public constructor( hasLeash: boolean, public isHappyDoggo: boolean, public aSimplerHappiness: boolean, options: PhetioObjectOptions ) {
@@ -281,7 +280,6 @@
 
       // Simplified example for the first test case
       class Dog extends PhetioObject {
-        // @ts-expect-error
         public [ attributeName ]: boolean;
 
         public constructor( hasLeash: boolean, public isHappyDoggo: boolean, options: PhetioObjectOptions ) {
Index: perennial-alias/js/common/ReleaseBranch.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial-alias/js/common/ReleaseBranch.ts b/perennial-alias/js/common/ReleaseBranch.ts
--- a/perennial-alias/js/common/ReleaseBranch.ts	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial-alias/js/common/ReleaseBranch.ts	(date 1765251272436)
@@ -11,6 +11,7 @@
 import axios from 'axios';
 import fs from 'fs';
 import _ from 'lodash';
+import pLimit from 'p-limit';
 import winston from 'winston';
 import affirm from '../browser-and-node/affirm.js';
 import SimVersion from '../browser-and-node/SimVersion.js';
@@ -50,8 +51,6 @@
 import simMetadata from './simMetadata.js';
 import simPhetioMetadata from './simPhetioMetadata.js';
 import withServer from './withServer.js';
-// @ts-expect-error
-import pLimit from 'p-limit';
 
 const MAINTENANCE_DIRECTORY = '../release-branches';
 
@@ -242,7 +241,7 @@
 
   public async checkUnbuilt(): Promise<string | null> {
     try {
-      return await withServer( async port => {
+      return await withServer( async ( port: number ) => {
         const url = `http://localhost:${port}/${this.repo}/${this.repo}_en.html?brand=phet&ea&fuzzMouse&fuzzTouch`;
         try {
           return await puppeteerLoad( url, {
@@ -265,7 +264,7 @@
     try {
       const usesChipper2 = await this.usesChipper2();
 
-      return await withServer( async port => {
+      return await withServer( async ( port: number ) => {
         const url = `http://localhost:${port}/${this.repo}/build/${usesChipper2 ? 'phet/' : ''}${this.repo}_en${usesChipper2 ? '_phet' : ''}.html?fuzzMouse&fuzzTouch`;
         try {
           return puppeteerLoad( url, {
Index: states-of-matter/js/atomic-interactions/view/AtomicInteractionsScreenView.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/states-of-matter/js/atomic-interactions/view/AtomicInteractionsScreenView.ts b/states-of-matter/js/atomic-interactions/view/AtomicInteractionsScreenView.ts
--- a/states-of-matter/js/atomic-interactions/view/AtomicInteractionsScreenView.ts	(revision bdfd3a43007b3ca3ac9cd1b96cf1e3c882f89e7d)
+++ b/states-of-matter/js/atomic-interactions/view/AtomicInteractionsScreenView.ts	(date 1765253600353)
@@ -162,17 +162,14 @@
 
     // add force control
     const forcesAccordionBox = new ForcesAccordionBox(
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       dualAtomModel.forcesDisplayModeProperty,
       dualAtomModel.forcesExpandedProperty,
       {
-        // @ts-expect-error
         tickTextColor: tickTextColor,
         textColor: textColor,
-        // @ts-expect-error
         fill: panelFill,
-        // @ts-expect-error
         stroke: panelStroke,
-        // @ts-expect-error
         textFill: panelTextFill,
         buttonAlign: forceControlPanelButtonAlign,
         showTitleWhenExpanded: !enableHeterogeneousAtoms,
@@ -301,6 +298,7 @@
       this.setShowRepulsiveForces( forces === ForceDisplayMode.COMPONENTS );
       this.setShowTotalForces( forces === ForceDisplayMode.TOTAL );
       if ( !this.showAttractiveForces && !this.showTotalForces && forces !== ForceDisplayMode.HIDDEN ) {
+        // eslint-disable-next-line @typescript-eslint/no-base-to-string
         throw new Error( `invalid forces: ${forces}` );
       }
     } );
Index: dot/js/util/toFixed.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/dot/js/util/toFixed.ts b/dot/js/util/toFixed.ts
--- a/dot/js/util/toFixed.ts	(revision 9d39bd282a981bbb05b19c99d7286f4814803e05)
+++ b/dot/js/util/toFixed.ts	(date 1765250590296)
@@ -12,7 +12,6 @@
  */
 
 import dot from '../dot.js';
-// @ts-expect-error - Big import requires this for some reason, but it works
 import Big from '../../../sherpa/lib/big-6.2.1.js'; // eslint-disable-line phet/default-import-match-filename
 
 export function toFixed( value: number, decimalPlaces: number ): string {
Index: states-of-matter/js/atomic-interactions/model/DualAtomModel.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/states-of-matter/js/atomic-interactions/model/DualAtomModel.ts b/states-of-matter/js/atomic-interactions/model/DualAtomModel.ts
--- a/states-of-matter/js/atomic-interactions/model/DualAtomModel.ts	(revision bdfd3a43007b3ca3ac9cd1b96cf1e3c882f89e7d)
+++ b/states-of-matter/js/atomic-interactions/model/DualAtomModel.ts	(date 1765291462474)
@@ -144,7 +144,11 @@
 
     // update the atom pair when the atom pair property is set
     this.atomPairProperty.link( atomPair => {
+
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       this.fixedAtom.atomTypeProperty.set( atomPair.fixedAtomType );
+
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       this.movableAtom.atomTypeProperty.set( atomPair.movableAtomType );
       this.ljPotentialCalculator.setSigma(
         SigmaTable.getSigma( this.fixedAtom.getType(), this.movableAtom.getType() )
@@ -288,7 +292,7 @@
 
     if ( this.isPlayingProperty.get() ) {
 
-      // Using real world time for this results in the atoms moving a little slowly, so the time step is adjusted here.
+      // Using real world time for these results in the atoms moving a little slowly, so the time step is adjusted here.
       // The multipliers were empirically determined.
       let adjustedTimeStep;
       if ( this.timeSpeedProperty.value === TimeSpeed.SLOW ) {
Index: bamboo/js/demo/DemoMultiplePlots.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/bamboo/js/demo/DemoMultiplePlots.ts b/bamboo/js/demo/DemoMultiplePlots.ts
--- a/bamboo/js/demo/DemoMultiplePlots.ts	(revision 06fbd3b45bb281f41a9a2ed92125f0f788929fb0)
+++ b/bamboo/js/demo/DemoMultiplePlots.ts	(date 1765253618892)
@@ -102,6 +102,7 @@
       ]
     } );
 
+    // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
     const linear = new Transform1( x => x, x => x );
     const transformProperty = new Property( linear );
     const controls = new VerticalAquaRadioButtonGroup( transformProperty, [
Index: ratio-and-proportion/js/common/view/RatioHalfTickMarksNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/ratio-and-proportion/js/common/view/RatioHalfTickMarksNode.ts b/ratio-and-proportion/js/common/view/RatioHalfTickMarksNode.ts
--- a/ratio-and-proportion/js/common/view/RatioHalfTickMarksNode.ts	(revision 8c9a71401cf97b2f77eecfb57a03f0de9fd27a1b)
+++ b/ratio-and-proportion/js/common/view/RatioHalfTickMarksNode.ts	(date 1765253603935)
@@ -58,6 +58,7 @@
 
     // subtract one to account for potential rounding errors. This helps guarantee that the last line is drawn.
     this.setLineSpacings( {
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       minorHorizontalLineSpacing: ( this.gridHeight - 1 ) / tickMarkRange
     } );
 
Index: energy-skate-park/js/graphs/view/EnergyGraphAccordionBox.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/energy-skate-park/js/graphs/view/EnergyGraphAccordionBox.ts b/energy-skate-park/js/graphs/view/EnergyGraphAccordionBox.ts
--- a/energy-skate-park/js/graphs/view/EnergyGraphAccordionBox.ts	(revision f53833562e8d25e8e888c3af2eda7f01b28d2d52)
+++ b/energy-skate-park/js/graphs/view/EnergyGraphAccordionBox.ts	(date 1765289660372)
@@ -203,6 +203,7 @@
     parentLayer.addChild( variableSwitch );
     parentLayer.addChild( eraserButton );
 
+    // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
     ManualConstraint.create( parentLayer, [ this, variableSwitch, eraserButton, energyPlot, energyPlot.chartPanel ], ( thisProxy, variableSwitchProxy, eraserButtonProxy, energyPlotProxy, chartPanelProxy ) => {
       variableSwitchProxy.centerY = ( chartPanelProxy.top + thisProxy.top ) / 2;
       variableSwitchProxy.centerX = chartPanelProxy.centerX;
@@ -248,6 +249,8 @@
    * perfectly align with grid lines in the plot.
    */
   public getContentRight(): number {
+
+    // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
     const localContentRight = this.globalToLocalBounds( this.energyPlot.localToGlobalBounds( this.energyPlot.chartPanel.localBounds ) ).right;
     const localPanelRight = this.localBounds.right;
     return localPanelRight - localContentRight;
Index: energy-skate-park/js/graphs/view/EnergyChart.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/energy-skate-park/js/graphs/view/EnergyChart.ts b/energy-skate-park/js/graphs/view/EnergyChart.ts
--- a/energy-skate-park/js/graphs/view/EnergyChart.ts	(revision f53833562e8d25e8e888c3af2eda7f01b28d2d52)
+++ b/energy-skate-park/js/graphs/view/EnergyChart.ts	(date 1765289635068)
@@ -276,6 +276,8 @@
 
       // add a listener that updates opacity with the EnergySkateParkDataSample Property, dispose it on removal
       const opacityListener = ( opacity: number ) => {
+
+        // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
         pointStyle.opacity = opacity;
       };
       addedSample.opacityProperty.link( opacityListener );
@@ -296,7 +298,7 @@
       //this.setCursorValue( independentVariable );
     } );
 
-    // remove a batch of of EnergySkateParkDataSamples
+    // remove a batch of EnergySkateParkDataSamples
     model.batchRemoveSamplesEmitter.addListener( samplesToRemove => {
 
       const plotTime = model.independentVariableProperty.get() === 'time';
@@ -305,6 +307,7 @@
         return plotTime ? sampleToRemove.time : ( sampleToRemove.position.x + POSITION_PLOT_OFFSET );
       } );
 
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       this.dynamicSeriesArray.forEach( dynamicSeries => {
         dynamicSeries.removeDataPointsAtX( xValuesToRemove );
       } );
Index: balancing-act/js/common/view/MysteryMassNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/view/MysteryMassNode.ts b/balancing-act/js/common/view/MysteryMassNode.ts
--- a/balancing-act/js/common/view/MysteryMassNode.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/view/MysteryMassNode.ts	(date 1765252771385)
@@ -6,6 +6,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import { TReadOnlyProperty } from '../../../../axon/js/TReadOnlyProperty.js';
 import ModelViewTransform2 from '../../../../phetcommon/js/view/ModelViewTransform2.js';
@@ -26,7 +27,7 @@
   private readonly mass: LabeledImageMass;
   private readonly labelCenterListener: () => void;
 
-  public constructor( mass: LabeledImageMass, modelViewTransform: ModelViewTransform2, isLabeled: boolean, massLabelVisibleProperty: TReadOnlyProperty<boolean>, draggable: boolean, columnStateProperty: Property<typeof ColumnState> ) {
+  public constructor( mass: LabeledImageMass, modelViewTransform: ModelViewTransform2, isLabeled: boolean, massLabelVisibleProperty: TReadOnlyProperty<boolean>, draggable: boolean, columnStateProperty: EnumerationDeprecatedProperty ) {
     super( mass, modelViewTransform, isLabeled, massLabelVisibleProperty, draggable, columnStateProperty );
     const inset = this.imageNode.width * INSET_PROPORTION;
 
Index: phetcommon/js/util/StringUtils.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/phetcommon/js/util/StringUtils.js b/phetcommon/js/util/StringUtils.js
--- a/phetcommon/js/util/StringUtils.js	(revision 6343150359f1fafb499144c7ea35abc465ebf47b)
+++ b/phetcommon/js/util/StringUtils.js	(date 1765250621395)
@@ -28,11 +28,12 @@
    * "2 + 3"
    *
    * @param {string} pattern pattern string, with N placeholders, where N is an integer
+   * @param {...*} values values to fill in the placeholders
    * @returns {string}
    * @public
    * @deprecated - please use StringUtils.fillIn
    */
-  format: function( pattern ) {
+  format: function( pattern, ...values ) {
     // eslint-disable-next-line prefer-rest-params
     const args = arguments;
     return pattern.replace( /{(\d)}/g, ( r, n ) => args[ +n + 1 ] );
Index: balancing-act/js/common/view/LevelSupportColumnNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/view/LevelSupportColumnNode.ts b/balancing-act/js/common/view/LevelSupportColumnNode.ts
--- a/balancing-act/js/common/view/LevelSupportColumnNode.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/view/LevelSupportColumnNode.ts	(date 1765252771370)
@@ -6,6 +6,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import ModelViewTransform2 from '../../../../phetcommon/js/view/ModelViewTransform2.js';
 import { GET_COLUMN_BODY_GRADIENT, GET_COLUMN_SUPPORT_GRADIENT } from '../../../../scenery-phet/js/LevelSupportColumnNode.js';
@@ -18,7 +19,7 @@
 
 export default class LevelSupportColumnNode extends Node {
 
-  public constructor( modelViewTransform: ModelViewTransform2, levelSupportColumn: LevelSupportColumn, columnState: Property<typeof ColumnState> ) {
+  public constructor( modelViewTransform: ModelViewTransform2, levelSupportColumn: LevelSupportColumn, columnState: EnumerationDeprecatedProperty ) {
     super();
 
     // Create and add the main body of the column.
Index: balancing-act/js/common/view/ColumnOnOffController.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/view/ColumnOnOffController.ts b/balancing-act/js/common/view/ColumnOnOffController.ts
--- a/balancing-act/js/common/view/ColumnOnOffController.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/view/ColumnOnOffController.ts	(date 1765252668801)
@@ -6,7 +6,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
-import Property from '../../../../axon/js/Property.js';
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import Dimension2 from '../../../../dot/js/Dimension2.js';
 import optionize from '../../../../phet-core/js/optionize.js';
 import Node, { NodeOptions } from '../../../../scenery/js/nodes/Node.js';
@@ -30,7 +30,7 @@
 
 class ColumnOnOffController extends Node {
 
-  public constructor( columnState: Property<typeof ColumnState>, providedOptions?: ColumnOnOffControllerOptions ) {
+  public constructor( columnState: EnumerationDeprecatedProperty, providedOptions?: ColumnOnOffControllerOptions ) {
 
     const options = optionize<ColumnOnOffControllerOptions, SelfOptions, NodeOptions>()( {
       tandem: Tandem.REQUIRED
Index: balancing-act/js/common/view/TiltedSupportColumnNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/view/TiltedSupportColumnNode.ts b/balancing-act/js/common/view/TiltedSupportColumnNode.ts
--- a/balancing-act/js/common/view/TiltedSupportColumnNode.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/view/TiltedSupportColumnNode.ts	(date 1765252771394)
@@ -7,6 +7,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import ModelViewTransform2 from '../../../../phetcommon/js/view/ModelViewTransform2.js';
 import { GET_COLUMN_BODY_GRADIENT, GET_COLUMN_SUPPORT_GRADIENT } from '../../../../scenery-phet/js/LevelSupportColumnNode.js';
@@ -19,7 +20,7 @@
 
 class TiltedSupportColumnNode extends Node {
 
-  public constructor( modelViewTransform: ModelViewTransform2, tiltedSupportColumn: TiltedSupportColumn, columnState: Property<typeof ColumnState> ) {
+  public constructor( modelViewTransform: ModelViewTransform2, tiltedSupportColumn: TiltedSupportColumn, columnState: EnumerationDeprecatedProperty ) {
     super();
 
     // Create and add the main body of the column.
Index: balancing-act/js/common/view/ImageMassNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/view/ImageMassNode.ts b/balancing-act/js/common/view/ImageMassNode.ts
--- a/balancing-act/js/common/view/ImageMassNode.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/view/ImageMassNode.ts	(date 1765252771382)
@@ -7,6 +7,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import PatternStringProperty from '../../../../axon/js/PatternStringProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import { TReadOnlyProperty } from '../../../../axon/js/TReadOnlyProperty.js';
@@ -41,7 +42,7 @@
 
   private readonly disposeImageMassNode: () => void;
 
-  public constructor( imageMass: ImageMass, modelViewTransform: ModelViewTransform2, isLabeled: boolean, massLabelVisibleProperty: TReadOnlyProperty<boolean>, draggable: boolean, columnStateProperty: Property<typeof ColumnState> ) {
+  public constructor( imageMass: ImageMass, modelViewTransform: ModelViewTransform2, isLabeled: boolean, massLabelVisibleProperty: TReadOnlyProperty<boolean>, draggable: boolean, columnStateProperty: EnumerationDeprecatedProperty ) {
     super( { cursor: 'pointer' } );
 
     BAQueryParameters.stanford && columnStateProperty.link( columnState => {
Index: balancing-act/js/common/view/MassNodeFactory.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/view/MassNodeFactory.ts b/balancing-act/js/common/view/MassNodeFactory.ts
--- a/balancing-act/js/common/view/MassNodeFactory.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/view/MassNodeFactory.ts	(date 1765252771392)
@@ -8,6 +8,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import { TReadOnlyProperty } from '../../../../axon/js/TReadOnlyProperty.js';
 import ModelViewTransform2 from '../../../../phetcommon/js/view/ModelViewTransform2.js';
@@ -25,7 +26,7 @@
 import MysteryMassNode from './MysteryMassNode.js';
 
 const MassNodeFactory = {
-  createMassNode( mass: Mass, modelViewTransform: ModelViewTransform2, isLabeled: boolean, labelVisibleProperty: TReadOnlyProperty<boolean>, columnStateProperty: Property<typeof ColumnState> ): Node {
+  createMassNode( mass: Mass, modelViewTransform: ModelViewTransform2, isLabeled: boolean, labelVisibleProperty: TReadOnlyProperty<boolean>, columnStateProperty: EnumerationDeprecatedProperty ): Node {
     let massNode;
     if ( mass instanceof MysteryMass ) {
       massNode = new MysteryMassNode( mass, modelViewTransform, isLabeled, labelVisibleProperty, true, columnStateProperty );
Index: balancing-act/js/common/view/PositionIndicatorControlPanel.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/view/PositionIndicatorControlPanel.ts b/balancing-act/js/common/view/PositionIndicatorControlPanel.ts
--- a/balancing-act/js/common/view/PositionIndicatorControlPanel.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/view/PositionIndicatorControlPanel.ts	(date 1765252771397)
@@ -7,6 +7,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import Multilink from '../../../../axon/js/Multilink.js';
 import Property from '../../../../axon/js/Property.js';
 import optionize from '../../../../phet-core/js/optionize.js';
@@ -40,7 +41,7 @@
 
 export default class PositionIndicatorControlPanel extends Panel {
 
-  public constructor( positionIndicatorStateProperty: Property<typeof PositionIndicatorChoice>, layoutBoundsWidth: number, providedOptions?: PositionIndicatorControlPanelOptions ) {
+  public constructor( positionIndicatorStateProperty: EnumerationDeprecatedProperty, layoutBoundsWidth: number, providedOptions?: PositionIndicatorControlPanelOptions ) {
 
     const options = optionize<PositionIndicatorControlPanelOptions, SelfOptions, PanelOptions>()( {
       titleToControlsVerticalSpace: 5,
Index: perennial-alias/js/grunt/typeCheck.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial-alias/js/grunt/typeCheck.ts b/perennial-alias/js/grunt/typeCheck.ts
--- a/perennial-alias/js/grunt/typeCheck.ts	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial-alias/js/grunt/typeCheck.ts	(date 1765250694681)
@@ -17,7 +17,7 @@
 import { PERENNIAL_ROOT } from '../common/perennialRepoUtils.js';
 
 const ALL_CONFIG_PATH = `${PERENNIAL_ROOT}/../chipper/dist/tsconfig/all/`;
-const tscCommand = `${PERENNIAL_ROOT}/node_modules/typescript/bin/tsc`;
+const tscCommand = `${PERENNIAL_ROOT}/node_modules/@typescript/native-preview/bin/tsgo`;
 
 export type CheckOptions = {
 
Index: molecule-shapes/js/common/view/MoleculeShapesScreenView.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/molecule-shapes/js/common/view/MoleculeShapesScreenView.js b/molecule-shapes/js/common/view/MoleculeShapesScreenView.js
--- a/molecule-shapes/js/common/view/MoleculeShapesScreenView.js	(revision 8f5648222b928e7932be6779bfc89b349d0cff82)
+++ b/molecule-shapes/js/common/view/MoleculeShapesScreenView.js	(date 1765291042269)
@@ -445,7 +445,7 @@
   }
 
   /**
-   * Removes a molcule view.
+   * Removes a molecule view.
    * @public
    *
    * @param {MoleculeView} moleculeView
@@ -454,10 +454,10 @@
     this.threeScene.remove( moleculeView );
   }
 
-  /*
+  /**
    * @private
-   * @param {Vector3} screenPoint
-   * @returns {THREE.Raycaster}
+   * @param {any} screenPoint
+   * @returns {*}
    */
   getRaycasterFromScreenPoint( screenPoint ) {
 
@@ -526,13 +526,13 @@
     return closestGroup;
   }
 
-  /*
+  /**
    * The position in the moleculeView's coordinate system (where z=0 in the view coordinate system) for a
    * corresponding screenPoint.
    * @public
    *
    * @param {Vector2} screenPoint
-   * @returns {THREE.Vector3} in the moleculeView's local coordinate system
+   * @returns {*} in the moleculeView's local coordinate system
    */
   getPlanarMoleculePosition( screenPoint ) {
     const cameraRay = this.getRayFromScreenPoint( screenPoint );
Index: balancing-act/js/common/model/BalanceModel.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/model/BalanceModel.ts b/balancing-act/js/common/model/BalanceModel.ts
--- a/balancing-act/js/common/model/BalanceModel.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/model/BalanceModel.ts	(date 1765252947103)
@@ -9,7 +9,6 @@
 
 import createObservableArray, { ObservableArray } from '../../../../axon/js/createObservableArray.js';
 import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
-import Property from '../../../../axon/js/Property.js';
 import Dimension2 from '../../../../dot/js/Dimension2.js';
 import Vector2 from '../../../../dot/js/Vector2.js';
 import Tandem from '../../../../tandem/js/Tandem.js';
@@ -31,7 +30,7 @@
   public readonly massList: ObservableArray<Mass>;
   public readonly userControlledMasses: Mass[];
 
-  public readonly columnStateProperty: Property<typeof ColumnState>;
+  public readonly columnStateProperty: EnumerationDeprecatedProperty;
   public readonly plank: Plank;
   public readonly supportColumns: LevelSupportColumn[];
 
Index: perennial-alias/js/grunt/decaf/buildDecaf.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial-alias/js/grunt/decaf/buildDecaf.ts b/perennial-alias/js/grunt/decaf/buildDecaf.ts
--- a/perennial-alias/js/grunt/decaf/buildDecaf.ts	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial-alias/js/grunt/decaf/buildDecaf.ts	(date 1765253603060)
@@ -98,6 +98,7 @@
   html = html.split( '{{PROJECT}}' ).join( project );
   html = html.split( '{{VERSION}}' ).join( versionString );
   html = html.split( '{{IS_BUILT}}' ).join( 'true' );
+  // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
   html = html.split( '\'{{PRELOAD_RESOURCES}}\'' ).join( preloadResources );
 
   fs.writeFileSync( `${buildDir}/${project}.html`, html );
Index: balancing-act/js/common/model/Plank.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/common/model/Plank.ts b/balancing-act/js/common/model/Plank.ts
--- a/balancing-act/js/common/model/Plank.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/common/model/Plank.ts	(date 1765252601481)
@@ -8,6 +8,7 @@
 
 import createObservableArray, { ObservableArray } from '../../../../axon/js/createObservableArray.js';
 import Emitter from '../../../../axon/js/Emitter.js';
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import NumberProperty from '../../../../axon/js/NumberProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import Matrix3 from '../../../../dot/js/Matrix3.js';
@@ -67,7 +68,7 @@
   private readonly massRemovedFromPlankEmitter: Emitter<[ string, number, number, Plank ]>;
 
   // Variables that need to be retained for dynamic behavior, but are not intended to be accessed externally
-  private readonly columnStateProperty: Property<typeof ColumnState>;
+  private readonly columnStateProperty: EnumerationDeprecatedProperty;
   private angularVelocity: number;
   private currentNetTorque: number;
 
@@ -77,7 +78,7 @@
   // Unrotated shape of the plank
   public readonly unrotatedShape: Shape;
 
-  public constructor( position: Vector2, pivotPoint: Vector2, columnStateProperty: Property<typeof ColumnState>, userControlledMasses: Mass[], tandem: Tandem ) {
+  public constructor( position: Vector2, pivotPoint: Vector2, columnStateProperty: EnumerationDeprecatedProperty, userControlledMasses: Mass[], tandem: Tandem ) {
     this.userControlledMasses = userControlledMasses;
 
     this.tiltAngleProperty = new NumberProperty( 0, {
Index: molecule-shapes/js/common/view/3d/LonePairView.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/molecule-shapes/js/common/view/3d/LonePairView.js b/molecule-shapes/js/common/view/3d/LonePairView.js
--- a/molecule-shapes/js/common/view/3d/LonePairView.js	(revision 8f5648222b928e7932be6779bfc89b349d0cff82)
+++ b/molecule-shapes/js/common/view/3d/LonePairView.js	(date 1765291032059)
@@ -132,13 +132,13 @@
     LonePairView.pool.put( this, this.renderer );
   }
 
-  /*
+  /**
    * Intersection hit-test to determine if a pointer is over the lone pair view.
    * @public
    *
    * @param {THREE.Ray} worldRay - Camera ray in world space
    * @param {boolean} isTouch - Whether expanded touch regions should be included
-   * @returns {THREE.Vector3|null} - The first intersection point (in world coordinates) found if it exists, otherwise
+   * @returns {*} - The first intersection point (in world coordinates) found if it exists, otherwise
    *                                 null. Note that we short-circuit the handling, so it may pick an intersection
    *                                 point on the opposite side - for now that's deemed an acceptable trade-off for
    *                                 performance.
Index: perennial/js/common/ReleaseBranch.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial/js/common/ReleaseBranch.ts b/perennial/js/common/ReleaseBranch.ts
--- a/perennial/js/common/ReleaseBranch.ts	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial/js/common/ReleaseBranch.ts	(date 1765251857538)
@@ -50,7 +50,6 @@
 import simMetadata from './simMetadata.js';
 import simPhetioMetadata from './simPhetioMetadata.js';
 import withServer from './withServer.js';
-// @ts-expect-error
 import pLimit from 'p-limit';
 
 const MAINTENANCE_DIRECTORY = '../release-branches';
@@ -242,6 +241,8 @@
 
   public async checkUnbuilt(): Promise<string | null> {
     try {
+
+      // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
       return await withServer( async port => {
         const url = `http://localhost:${port}/${this.repo}/${this.repo}_en.html?brand=phet&ea&fuzzMouse&fuzzTouch`;
         try {
@@ -265,6 +266,7 @@
     try {
       const usesChipper2 = await this.usesChipper2();
 
+      // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
       return await withServer( async port => {
         const url = `http://localhost:${port}/${this.repo}/build/${usesChipper2 ? 'phet/' : ''}${this.repo}_en${usesChipper2 ? '_phet' : ''}.html?fuzzMouse&fuzzTouch`;
         try {
Index: molecule-shapes/js/common/view/3d/AtomView.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/molecule-shapes/js/common/view/3d/AtomView.js b/molecule-shapes/js/common/view/3d/AtomView.js
--- a/molecule-shapes/js/common/view/3d/AtomView.js	(revision 8f5648222b928e7932be6779bfc89b349d0cff82)
+++ b/molecule-shapes/js/common/view/3d/AtomView.js	(date 1765291031980)
@@ -54,13 +54,13 @@
     }
   }
 
-  /*
+  /**
    * Intersection test for whether the mouse/touch is over this.
    * @public
    *
    * @param {THREE.Ray} worldRay - Camera ray in world space
    * @param {boolean} isTouch - Whether expanded touch regions should be included
-   * @returns {THREE.Vector3|null} - The first intersection point (in world coordinates) if it exists, otherwise null
+   * @returns {*} - The first intersection point (in world coordinates) if it exists, otherwise null
    */
   intersect( worldRay, isTouch ) {
     const inverseMatrix = new THREE.Matrix4();
Index: chipper/js/grunt/tasks/test-a11y.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/chipper/js/grunt/tasks/test-a11y.ts b/chipper/js/grunt/tasks/test-a11y.ts
--- a/chipper/js/grunt/tasks/test-a11y.ts	(revision 8e10063edf00fd80ab1bce6b664c24de473fa091)
+++ b/chipper/js/grunt/tasks/test-a11y.ts	(date 1765252888399)
@@ -94,6 +94,8 @@
   } );
 
   const minimumImpact = getMinimumImpact();
+
+  // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
   const results = await new AxeBuilder( { page: page } ).analyze();
   const filteredViolations = results.violations.filter( violation => {
     if ( SUPPRESSED_VIOLATION_IDS.has( violation.id ) ) {
Index: phet-io-wrappers/common/js/CredentialsDialog.tsx
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/phet-io-wrappers/common/js/CredentialsDialog.tsx b/phet-io-wrappers/common/js/CredentialsDialog.tsx
--- a/phet-io-wrappers/common/js/CredentialsDialog.tsx	(revision f48259a1d221831e2175eb1b3af2fcc8413069b1)
+++ b/phet-io-wrappers/common/js/CredentialsDialog.tsx	(date 1765289746620)
@@ -56,7 +56,10 @@
     return <div id="credentialsDialog" style={{
       border: 'black', display: 'inline-block', borderWidth: '1px', borderStyle: 'solid', margin: '10px',
       padding: '10px', position: 'fixed', top: '50%', left: '50%',
-      transform: 'translate(-50%, -50%)', webkitTransform: 'translate(-50%, -50%)',
+      transform: 'translate(-50%, -50%)',
+
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
+      webkitTransform: 'translate(-50%, -50%)',
       borderRadius: '10px', zIndex: 400, backgroundColor: 'white'
     }}>
       <div>
Index: quantum-measurement/js/bloch-sphere/view/BlochSphereScreenView.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/quantum-measurement/js/bloch-sphere/view/BlochSphereScreenView.ts b/quantum-measurement/js/bloch-sphere/view/BlochSphereScreenView.ts
--- a/quantum-measurement/js/bloch-sphere/view/BlochSphereScreenView.ts	(revision 04f0181a417e32538b45c84f5b4cd1d19cf06619)
+++ b/quantum-measurement/js/bloch-sphere/view/BlochSphereScreenView.ts	(date 1765250909433)
@@ -6,7 +6,7 @@
  * @author Agustín Vallejo
  */
 
-import BlochSphereModel from 'model/BlochSphereModel.js';
+import BlochSphereModel from '../model/BlochSphereModel.js';
 import Tandem from '../../../../tandem/js/Tandem.js';
 import QuantumMeasurementConstants from '../../common/QuantumMeasurementConstants.js';
 import ExperimentDividingLine from '../../common/view/ExperimentDividingLine.js';
Index: dot/js/Transform1.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/dot/js/Transform1.js b/dot/js/Transform1.ts
rename from dot/js/Transform1.js
rename to dot/js/Transform1.ts
--- a/dot/js/Transform1.js	(revision 9d39bd282a981bbb05b19c99d7286f4814803e05)
+++ b/dot/js/Transform1.ts	(date 1765253037643)
@@ -1,5 +1,8 @@
 // Copyright 2021-2022, University of Colorado Boulder
 
+// eslint-disable-next-line phet/bad-typescript-text
+// @ts-nocheck
+
 /**
  * One dimensional (scalar) transforms, which are invertible. Unlike Transform3 and Transform4, Transform1
  * may be nonlinear.
@@ -17,13 +20,9 @@
 
 class Transform1 {
 
-  /**
-   * @param {function(number):number} evaluationFunction
-   * @param {function(number):number} inverseFunction
-   * @param {Object} [options]
-   */
-  constructor( evaluationFunction, inverseFunction, options ) {
+  public constructor( evaluationFunction: ( x: number ) => number, inverseFunction: ( x: number ) => number, options ) {
 
+    // eslint-disable-next-line phet/bad-typescript-text
     options = merge( {
 
       // Used for asserting the inverse is correct, and that inputs are valid
Index: quantum-measurement/js/bloch-sphere/view/BlochSpherePreparationArea.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/quantum-measurement/js/bloch-sphere/view/BlochSpherePreparationArea.ts b/quantum-measurement/js/bloch-sphere/view/BlochSpherePreparationArea.ts
--- a/quantum-measurement/js/bloch-sphere/view/BlochSpherePreparationArea.ts	(revision 04f0181a417e32538b45c84f5b4cd1d19cf06619)
+++ b/quantum-measurement/js/bloch-sphere/view/BlochSpherePreparationArea.ts	(date 1765250926896)
@@ -7,7 +7,7 @@
  * @author Agustín Vallejo
  */
 
-import BlochSphereModel from 'model/BlochSphereModel.js';
+import BlochSphereModel from '../model/BlochSphereModel.js';
 import DerivedProperty from '../../../../axon/js/DerivedProperty.js';
 import PatternStringProperty from '../../../../axon/js/PatternStringProperty.js';
 import { roundToInterval } from '../../../../dot/js/util/roundToInterval.js';
Index: density-buoyancy-common/js/common/view/MaterialView.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/density-buoyancy-common/js/common/view/MaterialView.ts b/density-buoyancy-common/js/common/view/MaterialView.ts
--- a/density-buoyancy-common/js/common/view/MaterialView.ts	(revision 43e35f2826510d6105d638b7aac95c2ee4c1f183)
+++ b/density-buoyancy-common/js/common/view/MaterialView.ts	(date 1765251049857)
@@ -382,12 +382,12 @@
            new DebugMaterialView();
   }
 
-  public static readonly woodColorTexture = woodColorTexture;
-  public static readonly woodNormalTexture = woodNormalTexture;
-  public static readonly woodRoughnessTexture = woodRoughnessTexture;
+  public static readonly woodColorTexture: THREE.Texture = woodColorTexture;
+  public static readonly woodNormalTexture: THREE.Texture = woodNormalTexture;
+  public static readonly woodRoughnessTexture: THREE.Texture = woodRoughnessTexture;
 
-  public static readonly brickColorTexture = brickColorTexture;
-  public static readonly brickNormalTexture = brickNormalTexture;
+  public static readonly brickColorTexture: THREE.Texture = brickColorTexture;
+  public static readonly brickNormalTexture: THREE.Texture = brickNormalTexture;
 }
 
 export default MaterialView;
Index: density-buoyancy-common/js/buoyancy/model/shapes/DuckData.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/density-buoyancy-common/js/buoyancy/model/shapes/DuckData.ts b/density-buoyancy-common/js/buoyancy/model/shapes/DuckData.ts
--- a/density-buoyancy-common/js/buoyancy/model/shapes/DuckData.ts	(revision 43e35f2826510d6105d638b7aac95c2ee4c1f183)
+++ b/density-buoyancy-common/js/buoyancy/model/shapes/DuckData.ts	(date 1765254107748)
@@ -49,7 +49,7 @@
 // Parsing the geometry of the 3d duck
 const loader = new THREE.ObjectLoader();
 const mainDuckGeometry = loader.parse( DuckData );
-export const duckGeometry = ( mainDuckGeometry.children[ 0 ] as THREE.Mesh ).geometry;
+export const duckGeometry: THREE.BufferGeometry = ( mainDuckGeometry.children[ 0 ] as THREE.Mesh ).geometry;
 
 const minValues = new Vector3( 0, 0, 0 );
 const maxValues = new Vector3( 0, 0, 0 );
Index: perennial-alias/js/scripts/scenerystack-test.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial-alias/js/scripts/scenerystack-test.ts b/perennial-alias/js/scripts/scenerystack-test.ts
--- a/perennial-alias/js/scripts/scenerystack-test.ts	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial-alias/js/scripts/scenerystack-test.ts	(date 1765253603572)
@@ -211,6 +211,7 @@
 
     await viteBuild( './.scenerystack/demo-sim' );
 
+    // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
     const hasDisplay = await withServer( async port => {
       console.log( 'launching puppeteer' );
       return puppeteerEvaluate( `http://localhost:${port}/perennial/.scenerystack/demo-sim/dist/index.html`, '!!phet.joist.sim.display' );
@@ -258,6 +259,7 @@
       {
         console.log( `vite build ${repo}` );
         await viteBuild( `./.scenerystack/${repo}` );
+        // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
         await withServer( async port => {
           await puppeteerLoad( `http://localhost:${port}/perennial/.scenerystack/${repo}/dist/index.html` );
         } );
@@ -288,6 +290,7 @@
         console.log( `parcel build ${repo}` );
         await parcelBuild( `./.scenerystack/${repo}` );
         console.log( 'built' );
+        // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
         await withServer( async port => {
           await puppeteerLoad( `http://localhost:${port}/perennial/.scenerystack/${repo}/dist/index.html` );
         } );
Index: dot/js/Matrix.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/dot/js/Matrix.js b/dot/js/Matrix.js
--- a/dot/js/Matrix.js	(revision 9d39bd282a981bbb05b19c99d7286f4814803e05)
+++ b/dot/js/Matrix.js	(date 1765253203578)
@@ -15,6 +15,11 @@
 const ArrayType = window.Float64Array || Array;
 
 export default class Matrix {
+
+  // declare the dimensions n and m, which are numbers
+  n;
+  m;
+
   /**
    * @param {number} m - number of rows
    * @param {number} n - number of columns
Index: energy-forms-and-changes/js/intro/view/BlockNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/energy-forms-and-changes/js/intro/view/BlockNode.ts b/energy-forms-and-changes/js/intro/view/BlockNode.ts
--- a/energy-forms-and-changes/js/intro/view/BlockNode.ts	(revision e3e92915041ff448d4cae4f9ae3b07a29c5ee727)
+++ b/energy-forms-and-changes/js/intro/view/BlockNode.ts	(date 1765289509482)
@@ -99,6 +99,7 @@
     this.block = block;
 
     // extract the scale transform from the MVT so that we can separate the shape from the position of the block
+    // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
     const scaleVector = modelViewTransform.matrix.getScaleVector();
     const scaleTransform = new Transform3( Matrix3.scaling( scaleVector.x, -scaleVector.y ) );
 
Index: states-of-matter/js/common/model/MultipleParticleModel.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/states-of-matter/js/common/model/MultipleParticleModel.ts b/states-of-matter/js/common/model/MultipleParticleModel.ts
--- a/states-of-matter/js/common/model/MultipleParticleModel.ts	(revision bdfd3a43007b3ca3ac9cd1b96cf1e3c882f89e7d)
+++ b/states-of-matter/js/common/model/MultipleParticleModel.ts	(date 1765253618935)
@@ -738,6 +738,7 @@
     // Initialize the atoms.
     switch( this.substanceProperty.get() ) {
       case SubstanceType.DIATOMIC_OXYGEN:
+        // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
         this.initializeDiatomic( this.substanceProperty.get(), phase );
         break;
       case SubstanceType.NEON:
@@ -750,6 +751,7 @@
         this.initializeMonatomic( this.substanceProperty.get(), phase );
         break;
       case SubstanceType.WATER:
+        // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
         this.initializeTriatomic( this.substanceProperty.get(), phase );
         break;
       default:
@@ -1354,6 +1356,7 @@
    */
   public toStateObject(): MultipleParticleModelStateObject {
     return {
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       _substance: EnumerationIO( SubstanceType ).toStateObject( this.substanceProperty.value ),
       _isExploded: this.isExplodedProperty.value,
       _containerHeight: this.containerHeightProperty.value,
Index: perennial-alias/package.json
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial-alias/package.json b/perennial-alias/package.json
--- a/perennial-alias/package.json	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial-alias/package.json	(date 1765241356385)
@@ -63,6 +63,7 @@
     "ts-morph": "~21.0.1",
     "tsx": "~4.19.1",
     "typescript": "~5.7.2",
+    "@typescript/native-preview": "^7.0.0-dev.20251208.1",
     "winston": "~2.4.5",
     "winston-loggly": "~1.3.1",
     "xml2js": "~0.4.15"
Index: mobius/js/NodeTexture.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/mobius/js/NodeTexture.ts b/mobius/js/NodeTexture.ts
--- a/mobius/js/NodeTexture.ts	(revision ccd82a8e40d7dfc0126faf8589ca4917a6a73641)
+++ b/mobius/js/NodeTexture.ts	(date 1765253600978)
@@ -67,6 +67,7 @@
     } );
     display.updateDisplay();
 
+    // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
     const canvas = display.rootBackbone.blocks[ 0 ].canvas;
 
     super( canvas );
Index: alpenglow/js/webgpu/WebGPURecorder.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/alpenglow/js/webgpu/WebGPURecorder.ts b/alpenglow/js/webgpu/WebGPURecorder.ts
--- a/alpenglow/js/webgpu/WebGPURecorder.ts	(revision 5be64327955d4e8fa6fa7fa3eef050aec77fff04)
+++ b/alpenglow/js/webgpu/WebGPURecorder.ts	(date 1765251857550)
@@ -303,6 +303,8 @@
 
   // TODO: consider how we're handling this
   public static arrayBufferLikeString( data: ArrayLike<number> | ArrayBufferLike ): string {
+
+    // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
     return `new Uint8Array( [ ${new Uint8Array( data ).join( ', ' )} ] ).buffer`;
   }
 
@@ -369,7 +371,7 @@
       }
     }
     else {
-      const map: Record<string, string | undefined > = {};
+      const map: Record<string, string | undefined> = {};
       Object.keys( value ).forEach( key => {
         if ( objectOverrides && objectOverrides[ key ] ) {
           map[ key ] = objectOverrides[ key ]( value[ key ] );
@@ -403,6 +405,7 @@
     }
   }
 }
+
 alpenglow.register( 'WebGPURecorder', WebGPURecorder );
 
 export class WebGPUCommandList {
@@ -463,6 +466,7 @@
     } ).join( ', ' )} ` : ''}) => {\n${this.toJS( nameMap, level + 1 )}\n}`;
   }
 }
+
 alpenglow.register( 'WebGPUCommandList', WebGPUCommandList );
 
 const getName = ( nameMap: Map<IntentionalAny, string>, obj: IntentionalAny ): string => {
@@ -489,6 +493,7 @@
     }
   }
 }
+
 alpenglow.register( 'WebGPUCommand', WebGPUCommand );
 
 class WebGPUCommandGetAdapter extends WebGPUCommand {
@@ -533,7 +538,7 @@
         const numberValue = value as number;
         // eslint-disable-next-line phet/no-simple-type-checking-assertions
         assert && assert( typeof value === 'number' );
-        
+
         return WebGPURecorder.bitfieldToString( numberValue, new Map<number, string>( [
           [ GPUBufferUsage.MAP_READ, 'GPUBufferUsage.MAP_READ' ],
           [ GPUBufferUsage.MAP_WRITE, 'GPUBufferUsage.MAP_WRITE' ],
@@ -796,9 +801,7 @@
   }
 
   public toJS( nameMap: Map<IntentionalAny, string>, level = 0 ): string {
-    return `${this.getDeclaration( nameMap )}${getName( nameMap, this.commandEncoder )}.beginRenderPass( ${WebGPURecorder.rawValue( level, this.descriptor, nameMap, {
-      
-    } )} );`;
+    return `${this.getDeclaration( nameMap )}${getName( nameMap, this.commandEncoder )}.beginRenderPass( ${WebGPURecorder.rawValue( level, this.descriptor, nameMap, {} )} );`;
   }
 }
 
Index: mobius/js/ThreeIsometricNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/mobius/js/ThreeIsometricNode.ts b/mobius/js/ThreeIsometricNode.ts
--- a/mobius/js/ThreeIsometricNode.ts	(revision ccd82a8e40d7dfc0126faf8589ca4917a6a73641)
+++ b/mobius/js/ThreeIsometricNode.ts	(date 1765253725994)
@@ -96,6 +96,8 @@
 
       // support Scenery/Joist 0.2 screenshot (takes extra work to output)
       this.domNode.renderToCanvasSelf = ( wrapper, matrix ) => {
+
+        // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
         const context = wrapper.context;
 
         // Guaranteed to be affine, 1:1 aspect ratio and axis-aligned
Index: density-buoyancy-common/js/common/view/FluidIconMesh.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/density-buoyancy-common/js/common/view/FluidIconMesh.ts b/density-buoyancy-common/js/common/view/FluidIconMesh.ts
--- a/density-buoyancy-common/js/common/view/FluidIconMesh.ts	(revision 43e35f2826510d6105d638b7aac95c2ee4c1f183)
+++ b/density-buoyancy-common/js/common/view/FluidIconMesh.ts	(date 1765254269925)
@@ -13,7 +13,7 @@
 
 export default class FluidIconMesh extends THREE.Mesh {
 
-  public constructor( position: Vector3 = new Vector3( 0, -0.5, 0.1 ), fluidGeometry = new THREE.BoxGeometry( 1, 1, 0.2 ) ) {
+  public constructor( position: Vector3 = new Vector3( 0, -0.5, 0.1 ), fluidGeometry: THREE.BoxGeometry = new THREE.BoxGeometry( 1, 1, 0.2 ) ) {
 
     const fluidMaterial = new THREE.MeshLambertMaterial( {
       transparent: true
Index: mobius/js/ThreeUtils.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/mobius/js/ThreeUtils.ts b/mobius/js/ThreeUtils.ts
--- a/mobius/js/ThreeUtils.ts	(revision ccd82a8e40d7dfc0126faf8589ca4917a6a73641)
+++ b/mobius/js/ThreeUtils.ts	(date 1765254246206)
@@ -18,27 +18,27 @@
 
 const scratchFloatArray = new Float32Array( 128 );
 
-const ThreeUtils = {
+export class ThreeUtils {
   /**
    * Converts a Vector3 to a THREE.Vector3
    */
-  vectorToThree( vector: Vector3 ): THREE.Vector3 {
+  public static vectorToThree( vector: Vector3 ): THREE.Vector3 {
     return new THREE.Vector3( vector.x, vector.y, vector.z );
-  },
+  }
 
   /**
    * Converts a THREE.Vector3 to a Vector3
    */
-  threeToVector( vector: THREE.Vector3 ): Vector3 {
+  public static threeToVector( vector: THREE.Vector3 ): Vector3 {
     return new Vector3( vector.x, vector.y, vector.z );
-  },
+  }
 
   /**
    * Converts a Color to a THREE.Color
    */
-  colorToThree( color: Color ): THREE.Color {
+  public static colorToThree( color: Color ): THREE.Color {
     return new THREE.Color( color.toNumber() );
-  },
+  }
 
   /**
    * Returns an array of [ x, y, z, ... ] vertices for a quad pointed towards the camera.
@@ -46,9 +46,9 @@
    * @param bounds2 - x,y
    * @param z
    */
-  frontVertices( bounds2: Bounds2, z: number ): Float32Array {
+  public static frontVertices( bounds2: Bounds2, z: number ): Float32Array {
     return scratchFloatArray.slice( 0, ThreeUtils.writeFrontVertices( scratchFloatArray, 0, bounds2, z ) );
-  },
+  }
 
   /**
    * Returns an array of [ x, y, z, ... ] vertices for a quad pointed up.
@@ -56,9 +56,9 @@
    * @param bounds2 - x,z
    * @param y
    */
-  topVertices( bounds2: Bounds2, y: number ): Float32Array {
+  public static topVertices( bounds2: Bounds2, y: number ): Float32Array {
     return scratchFloatArray.slice( 0, ThreeUtils.writeTopVertices( scratchFloatArray, 0, bounds2, y ) );
-  },
+  }
 
   /**
    * Returns an array of [ x, y, z, ... ] vertices for a quad pointed towards the right.
@@ -66,19 +66,19 @@
    * @param bounds2 - z,y
    * @param x
    */
-  rightVertices( bounds2: Bounds2, x: number ): Float32Array {
+  public static rightVertices( bounds2: Bounds2, x: number ): Float32Array {
     return scratchFloatArray.slice( 0, ThreeUtils.writeRightVertices( scratchFloatArray, 0, bounds2, x ) );
-  },
+  }
 
   /**
    * Returns an array of [ x, y, z, ... ] vertices for a quad pointed towards the left.
    *
-   * @param Bounds2 bounds2 - z,y
-   * @param number x
+   * @param bounds2 - z,y
+   * @param x
    */
-  leftVertices( bounds2: Bounds2, x: number ): Float32Array {
+  public static leftVertices( bounds2: Bounds2, x: number ): Float32Array {
     return scratchFloatArray.slice( 0, ThreeUtils.writeLeftVertices( scratchFloatArray, 0, bounds2, x ) );
-  },
+  }
 
   /**
    * Writes a single triangle into a buffer, returning the new index location. Assumes vertices in counterclockwise
@@ -88,7 +88,7 @@
    *
    * @returns - The index for the next write
    */
-  writeTriangle( array: Float32Array | Float64Array, index: number, x0: number, y0: number, z0: number, x1: number, y1: number, z1: number, x2: number, y2: number, z2: number ): number {
+  public static writeTriangle( array: Float32Array | Float64Array, index: number, x0: number, y0: number, z0: number, x1: number, y1: number, z1: number, x2: number, y2: number, z2: number ): number {
     array[ index + 0 ] = x0;
     array[ index + 1 ] = y0;
     array[ index + 2 ] = z0;
@@ -100,7 +100,7 @@
     array[ index + 8 ] = z2;
 
     return index + 9;
-  },
+  }
 
   /**
    * Writes a single quad into a buffer, returning the new index location. Assumes verties in counterclockwise order.
@@ -109,7 +109,7 @@
    *
    * @returns - The index for the next write
    */
-  writeQuad( array: Float32Array | Float64Array, index: number, x0: number, y0: number, z0: number, x1: number, y1: number, z1: number, x2: number, y2: number, z2: number, x3: number, y3: number, z3: number ): number {
+  public static writeQuad( array: Float32Array | Float64Array, index: number, x0: number, y0: number, z0: number, x1: number, y1: number, z1: number, x2: number, y2: number, z2: number, x3: number, y3: number, z3: number ): number {
     index = ThreeUtils.writeTriangle(
       array, index,
       x0, y0, z0,
@@ -123,7 +123,7 @@
       x3, y3, z3
     );
     return index;
-  },
+  }
 
   /**
    * Writes a single front-facing quad into a buffer, returning the new index location. Assumes verties in
@@ -133,7 +133,7 @@
    *
    * @returns - The index for the next write
    */
-  writeFrontVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, z: number ): number {
+  public static writeFrontVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, z: number ): number {
     return ThreeUtils.writeQuad(
       array, index,
       bounds2.minX, bounds2.maxY, z,
@@ -141,7 +141,7 @@
       bounds2.maxX, bounds2.minY, z,
       bounds2.maxX, bounds2.maxY, z
     );
-  },
+  }
 
   /**
    * Writes a single up-facing quad into a buffer, returning the new index location. Assumes verties in
@@ -155,7 +155,7 @@
    * @param y
    * @returns - The index for the next write
    */
-  writeTopVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, y: number ): number {
+  public static writeTopVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, y: number ): number {
     return ThreeUtils.writeQuad(
       array, index,
       bounds2.minX, y, bounds2.maxY,
@@ -163,10 +163,10 @@
       bounds2.maxX, y, bounds2.minY,
       bounds2.minX, y, bounds2.minY
     );
-  },
+  }
 
   /**
-   * Writes a single right-facing quad into a buffer, returning the new index location. Assumes verties in
+   * Writes a single right-facing quad into a buffer, returning the new index location. Assumes vertices in
    * counterclockwise order.
    *
    * Writes 18 entries into the array.
@@ -177,7 +177,7 @@
    * @param x
    * @returns - The index for the next write
    */
-  writeRightVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, x: number ): number {
+  public static writeRightVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, x: number ): number {
     return ThreeUtils.writeQuad(
       array, index,
       x, bounds2.minY, bounds2.maxX,
@@ -185,7 +185,7 @@
       x, bounds2.maxY, bounds2.minX,
       x, bounds2.maxY, bounds2.maxX
     );
-  },
+  }
 
   /**
    * Writes a single left-facing quad into a buffer, returning the new index location. Assumes verties in
@@ -199,7 +199,7 @@
    * @param x
    * @returns - The index for the next write
    */
-  writeLeftVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, x: number ): number {
+  public static writeLeftVertices( array: Float32Array | Float64Array, index: number, bounds2: Bounds2, x: number ): number {
     return ThreeUtils.writeQuad(
       array, index,
       x, bounds2.minY, bounds2.maxX,
@@ -207,37 +207,37 @@
       x, bounds2.maxY, bounds2.minX,
       x, bounds2.minY, bounds2.minX
     );
-  },
+  }
 
   /**
    * Returns a THREE.TextureLoader instance (using a singleton so we don't create more than we need).
    */
-  get textureLoader(): THREE.TextureLoader {
+  public static get textureLoader(): THREE.TextureLoader {
     if ( !textureLoader ) {
       textureLoader = new THREE.TextureLoader();
     }
     return textureLoader;
-  },
+  }
 
   /**
    * Returns a THREE.Texture for a given HTMLImageElement.
    */
-  imageToTexture( image: HTMLImageElement, waitForLoad?: boolean ): THREE.Texture {
+  public static imageToTexture( image: HTMLImageElement, waitForLoad?: boolean ): THREE.Texture {
     if ( waitForLoad ) {
       return ThreeUtils.textureLoader.load( image.src, asyncLoader.createLock() );
     }
     else {
       return ThreeUtils.textureLoader.load( image.src );
     }
-  },
+  }
 
   /**
    * Checks if webgl is enabled by the browser.
    */
-  isWebGLEnabled(): boolean {
+  public static isWebGLEnabled(): boolean {
     return phet.chipper.queryParameters.webgl && Utils.isWebGLSupported;
   }
-};
+}
 
 mobius.register( 'ThreeUtils', ThreeUtils );
 export default ThreeUtils;
\ No newline at end of file
Index: balancing-act/js/balancelab/view/ModelElementCreatorNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/balancelab/view/ModelElementCreatorNode.ts b/balancing-act/js/balancelab/view/ModelElementCreatorNode.ts
--- a/balancing-act/js/balancelab/view/ModelElementCreatorNode.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/balancelab/view/ModelElementCreatorNode.ts	(date 1765291552471)
@@ -7,7 +7,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
-import Property from '../../../../axon/js/Property.js';
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import { TReadOnlyProperty } from '../../../../axon/js/TReadOnlyProperty.js';
 import Vector2 from '../../../../dot/js/Vector2.js';
 import affirm from '../../../../perennial-alias/js/browser-and-node/affirm.js';
@@ -47,7 +47,7 @@
   private selectionNode?: Node;
   private caption?: Text;
 
-  public constructor( screenView: BasicBalanceScreenView, columnStateProperty: Property<typeof ColumnState>, providedOptions?: ModelElementCreatorNodeOptions ) {
+  public constructor( screenView: BasicBalanceScreenView, columnStateProperty: EnumerationDeprecatedProperty, providedOptions?: ModelElementCreatorNodeOptions ) {
 
     const options = optionize<ModelElementCreatorNodeOptions, SelfOptions, NodeOptions>()( {
       cursor: 'pointer',
Index: balancing-act/js/balancelab/view/MassCreatorNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/balancelab/view/MassCreatorNode.ts b/balancing-act/js/balancelab/view/MassCreatorNode.ts
--- a/balancing-act/js/balancelab/view/MassCreatorNode.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/balancelab/view/MassCreatorNode.ts	(date 1765252771390)
@@ -6,6 +6,7 @@
  * @author John Blanco (PhET Interactive Simulations)
  */
 
+import EnumerationDeprecatedProperty from '../../../../axon/js/EnumerationDeprecatedProperty.js';
 import PatternStringProperty from '../../../../axon/js/PatternStringProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import balancingAct from '../../balancingAct.js';
@@ -19,7 +20,7 @@
 
 export default class MassCreatorNode extends ModelElementCreatorNode {
 
-  public constructor( screenView: BasicBalanceScreenView, massValue: number, showMassLabel: boolean, columnStateProperty: Property<typeof ColumnState>, options?: ModelElementCreatorNodeOptions ) {
+  public constructor( screenView: BasicBalanceScreenView, massValue: number, showMassLabel: boolean, columnStateProperty: EnumerationDeprecatedProperty, options?: ModelElementCreatorNodeOptions ) {
     super( screenView, columnStateProperty, options );
     if ( showMassLabel ) {
       this.setCaption( new PatternStringProperty( pattern0Value1UnitsStringProperty, {
Index: energy-forms-and-changes/js/common/view/BeakerView.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/energy-forms-and-changes/js/common/view/BeakerView.ts b/energy-forms-and-changes/js/common/view/BeakerView.ts
--- a/energy-forms-and-changes/js/common/view/BeakerView.ts	(revision e3e92915041ff448d4cae4f9ae3b07a29c5ee727)
+++ b/energy-forms-and-changes/js/common/view/BeakerView.ts	(date 1765253601987)
@@ -106,6 +106,7 @@
 
     // extract the scale transform from the MVT so that we can separate the shape from the position
     const scaleTransform = new Transform3(
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       Matrix3.scaling( modelViewTransform.matrix.m00(), modelViewTransform.matrix.m11() )
     );
 
Index: bamboo/js/ChartTransform.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/bamboo/js/ChartTransform.ts b/bamboo/js/ChartTransform.ts
--- a/bamboo/js/ChartTransform.ts	(revision 06fbd3b45bb281f41a9a2ed92125f0f788929fb0)
+++ b/bamboo/js/ChartTransform.ts	(date 1765253600853)
@@ -57,11 +57,13 @@
       viewWidth: 100,
       modelXRange: new Range( -1, 1 ),
       modelXRangeInverted: false,
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       xTransform: new Transform1( x => x, x => x ),
 
       viewHeight: 100,
       modelYRange: new Range( -1, 1 ),
       modelYRangeInverted: false,
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       yTransform: new Transform1( x => x, x => x )
     }, providedOptions );
 
Index: axon/js/EnumerationDeprecatedProperty.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/axon/js/EnumerationDeprecatedProperty.js b/axon/js/EnumerationDeprecatedProperty.ts
rename from axon/js/EnumerationDeprecatedProperty.js
rename to axon/js/EnumerationDeprecatedProperty.ts
--- a/axon/js/EnumerationDeprecatedProperty.js	(revision eb375db9e99ab4b104e99badc492059c5a1c6ccf)
+++ b/axon/js/EnumerationDeprecatedProperty.ts	(date 1765252947099)
@@ -1,5 +1,9 @@
 // Copyright 2025, University of Colorado Boulder
 
+// see https://github.com/phetsims/chipper/issues/1651
+// eslint-disable-next-line phet/bad-typescript-text
+// @ts-nocheck
+
 /**
  * Property whose value is a member of an Enumeration.
  *
@@ -9,6 +13,7 @@
 import deprecationWarning from '../../phet-core/js/deprecationWarning.js';
 import EnumerationDeprecated from '../../phet-core/js/EnumerationDeprecated.js';
 import merge from '../../phet-core/js/merge.js';
+import IntentionalAny from '../../phet-core/js/types/IntentionalAny.js';
 import EnumerationIO from '../../tandem/js/types/EnumerationIO.js';
 import axon from './axon.js';
 import Property from './Property.js';
@@ -16,17 +21,14 @@
 /**
  * @deprecated
  */
-class EnumerationDeprecatedProperty extends Property {
+class EnumerationDeprecatedProperty extends Property<object> {
 
-  /**
-   * @param {EnumerationDeprecated | any} enumeration
-   * @param {*} initialValue - one of the values from enumeration
-   * @param {Object} [options]
-   */
-  constructor( enumeration, initialValue, options ) {
+  public constructor( enumeration: EnumerationDeprecated | IntentionalAny, initialValue: object, options?: IntentionalAny ) {
     deprecationWarning( 'Use EnumerationProperty. EnumerationDeprecated should be exchanged for classes that extend EnumerationValue, see WilderEnumerationPatterns for examples.' );
 
+    // eslint-disable-next-line phet/no-simple-type-checking-assertions
     assert && assert( enumeration instanceof EnumerationDeprecated, 'likely you are using the new and improved Enumeration, better use EnumerationProperty too.' );
+    // eslint-disable-next-line @typescript-eslint/no-base-to-string
     assert && assert( enumeration.VALUES.includes( initialValue ), `invalid initialValue: ${initialValue}` );
 
     if ( options ) {
Index: perennial/js/grunt/decaf/buildDecaf.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial/js/grunt/decaf/buildDecaf.ts b/perennial/js/grunt/decaf/buildDecaf.ts
--- a/perennial/js/grunt/decaf/buildDecaf.ts	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial/js/grunt/decaf/buildDecaf.ts	(date 1765251857554)
@@ -98,6 +98,8 @@
   html = html.split( '{{PROJECT}}' ).join( project );
   html = html.split( '{{VERSION}}' ).join( versionString );
   html = html.split( '{{IS_BUILT}}' ).join( 'true' );
+
+  // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
   html = html.split( '\'{{PRELOAD_RESOURCES}}\'' ).join( preloadResources );
 
   fs.writeFileSync( `${buildDir}/${project}.html`, html );
Index: chipper/js/common/pre-commit/pre-commit-task.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/chipper/js/common/pre-commit/pre-commit-task.ts b/chipper/js/common/pre-commit/pre-commit-task.ts
--- a/chipper/js/common/pre-commit/pre-commit-task.ts	(revision 8e10063edf00fd80ab1bce6b664c24de473fa091)
+++ b/chipper/js/common/pre-commit/pre-commit-task.ts	(date 1765253602875)
@@ -109,6 +109,7 @@
             ]
           } );
 
+          // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
           const result = await withServer( async port => {
             return puppeteerQUnit( browser, `http://localhost:${port}/${testFilePath}?ea&brand=phet-io` );
           } );
Index: mobius/js/ThreeNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/mobius/js/ThreeNode.ts b/mobius/js/ThreeNode.ts
--- a/mobius/js/ThreeNode.ts	(revision ccd82a8e40d7dfc0126faf8589ca4917a6a73641)
+++ b/mobius/js/ThreeNode.ts	(date 1765253780520)
@@ -86,6 +86,7 @@
       this.domNode.renderToCanvasSelf = wrapper => {
         const canvas = this.stage.renderToCanvas( MobiusQueryParameters.mobiusCanvasSupersampling );
 
+        // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
         const context = wrapper.context;
         context.save();
 
Index: under-pressure/js/under-pressure-main.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/under-pressure/js/under-pressure-main.ts b/under-pressure/js/under-pressure-main.ts
--- a/under-pressure/js/under-pressure-main.ts	(revision 85d4dbfab76459506300476689e66117daebbb6c)
+++ b/under-pressure/js/under-pressure-main.ts	(date 1765253604125)
@@ -13,6 +13,7 @@
 const underPressureTitleStringProperty = UnderPressureStrings[ 'under-pressure' ].titleStringProperty;
 
 simLauncher.launch( () => {
+  // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
   const sim = new Sim( underPressureTitleStringProperty, [ new UnderPressureScreen() ], {
     credits: {
       leadDesign: 'Sam Reid',
Index: states-of-matter/js/states/view/StatesPhaseControlNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/states-of-matter/js/states/view/StatesPhaseControlNode.ts b/states-of-matter/js/states/view/StatesPhaseControlNode.ts
--- a/states-of-matter/js/states/view/StatesPhaseControlNode.ts	(revision bdfd3a43007b3ca3ac9cd1b96cf1e3c882f89e7d)
+++ b/states-of-matter/js/states/view/StatesPhaseControlNode.ts	(date 1765253600664)
@@ -130,6 +130,7 @@
         // If the change is from the state engine, then the phase will be set implicitly when the positions and velocities
         // of the molecules are set.
         if ( !isSettingPhetioStateProperty.value ) {
+          // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
           model.setPhase( state );
         }
       }
Index: states-of-matter/js/states/view/StatesScreenView.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/states-of-matter/js/states/view/StatesScreenView.ts b/states-of-matter/js/states/view/StatesScreenView.ts
--- a/states-of-matter/js/states/view/StatesScreenView.ts	(revision bdfd3a43007b3ca3ac9cd1b96cf1e3c882f89e7d)
+++ b/states-of-matter/js/states/view/StatesScreenView.ts	(date 1765253600763)
@@ -97,6 +97,7 @@
     );
 
     // selection panel for the atoms/molecules
+    // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
     const moleculesControlPanel = new StatesMoleculesControlPanel( multipleParticleModel.substanceProperty, {
       right: this.layoutBounds.right - CONTROL_PANEL_X_INSET,
       top: this.layoutBounds.top + CONTROL_PANEL_Y_INSET,
Index: dot/js/UnivariatePolynomial.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/dot/js/UnivariatePolynomial.ts b/dot/js/UnivariatePolynomial.ts
--- a/dot/js/UnivariatePolynomial.ts	(revision 9d39bd282a981bbb05b19c99d7286f4814803e05)
+++ b/dot/js/UnivariatePolynomial.ts	(date 1765250576922)
@@ -196,9 +196,7 @@
 
       const decomp = new EigenvalueDecomposition( companionMatrix );
 
-      // @ts-expect-error
       const realValues: Float64Array = decomp.getRealEigenvalues();
-      // @ts-expect-error
       const imaginaryValues: Float64Array = decomp.getImagEigenvalues();
       const decompValues = _.range( 0, this.degree ).map( i => new Complex( realValues[ i ], imaginaryValues[ i ] ) );
 
Index: scenery/js/display/Display.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/scenery/js/display/Display.ts b/scenery/js/display/Display.ts
--- a/scenery/js/display/Display.ts	(revision e061f0cc28be8ee7667878bda53106e48dac2b11)
+++ b/scenery/js/display/Display.ts	(date 1765250654790)
@@ -51,6 +51,7 @@
  */
 
 import Emitter from '../../../axon/js/Emitter.js';
+import Property from '../../../axon/js/Property.js';
 import stepTimer from '../../../axon/js/stepTimer.js';
 import TinyProperty from '../../../axon/js/TinyProperty.js';
 import TProperty from '../../../axon/js/TProperty.js';
@@ -65,48 +66,47 @@
 import PhetioObject, { PhetioObjectOptions } from '../../../tandem/js/PhetioObject.js';
 import AriaLiveAnnouncer from '../../../utterance-queue/js/AriaLiveAnnouncer.js';
 import UtteranceQueue from '../../../utterance-queue/js/UtteranceQueue.js';
+import FocusManager from '../accessibility/FocusManager.js';
+import globalKeyStateTracker from '../accessibility/globalKeyStateTracker.js';
+import HighlightVisibilityController from '../accessibility/HighlightVisibilityController.js';
+import KeyboardUtils from '../accessibility/KeyboardUtils.js';
+import { PDOM_UNIQUE_ID_SEPARATOR } from '../accessibility/pdom/PDOM_UNIQUE_ID_SEPARATOR.js';
+import PDOMInstance from '../accessibility/pdom/PDOMInstance.js';
+import PDOMSiblingStyle from '../accessibility/pdom/PDOMSiblingStyle.js';
+import PDOMTree from '../accessibility/pdom/PDOMTree.js';
+import PDOMUtils from '../accessibility/pdom/PDOMUtils.js';
 import BackboneDrawable from '../display/BackboneDrawable.js';
 import Block from '../display/Block.js';
 import CanvasBlock from '../display/CanvasBlock.js';
-import CanvasNodeBoundsOverlay from '../overlays/CanvasNodeBoundsOverlay.js';
 import ChangeInterval from '../display/ChangeInterval.js';
-import Color from '../util/Color.js';
 import DOMBlock from '../display/DOMBlock.js';
+import Drawable from '../display/Drawable.js';
 import DOMDrawable from '../display/drawables/DOMDrawable.js';
-import Drawable from '../display/Drawable.js';
-import Features from '../util/Features.js';
+import Instance from '../display/Instance.js';
+import Renderer from '../display/Renderer.js';
+import SelfDrawable from '../display/SelfDrawable.js';
+import WebGLBlock from '../display/WebGLBlock.js';
+import type { InputOptions } from '../input/Input.js';
+import Input from '../input/Input.js';
+import Pointer from '../input/Pointer.js';
+import SceneryEvent from '../input/SceneryEvent.js';
+import type TInputListener from '../input/TInputListener.js';
+import Node from '../nodes/Node.js';
+import CanvasNodeBoundsOverlay from '../overlays/CanvasNodeBoundsOverlay.js';
 import FittedBlockBoundsOverlay from '../overlays/FittedBlockBoundsOverlay.js';
-import FocusManager from '../accessibility/FocusManager.js';
-import FullScreen from '../util/FullScreen.js';
-import globalKeyStateTracker from '../accessibility/globalKeyStateTracker.js';
 import HighlightOverlay from '../overlays/HighlightOverlay.js';
 import HitAreaOverlay from '../overlays/HitAreaOverlay.js';
-import Input from '../input/Input.js';
-import type { InputOptions } from '../input/Input.js';
-import Instance from '../display/Instance.js';
-import KeyboardUtils from '../accessibility/KeyboardUtils.js';
-import Node from '../nodes/Node.js';
-import PDOMInstance from '../accessibility/pdom/PDOMInstance.js';
-import PDOMSiblingStyle from '../accessibility/pdom/PDOMSiblingStyle.js';
-import PDOMTree from '../accessibility/pdom/PDOMTree.js';
-import PDOMUtils from '../accessibility/pdom/PDOMUtils.js';
-import Pointer from '../input/Pointer.js';
 import PointerAreaOverlay from '../overlays/PointerAreaOverlay.js';
 import PointerOverlay from '../overlays/PointerOverlay.js';
-import Renderer from '../display/Renderer.js';
+import SafariWorkaroundOverlay from '../overlays/SafariWorkaroundOverlay.js';
+import type TOverlay from '../overlays/TOverlay.js';
 import scenery from '../scenery.js';
-import SceneryEvent from '../input/SceneryEvent.js';
-import SelfDrawable from '../display/SelfDrawable.js';
-import type TInputListener from '../input/TInputListener.js';
-import type TOverlay from '../overlays/TOverlay.js';
+import Color from '../util/Color.js';
+import Features from '../util/Features.js';
+import FullScreen from '../util/FullScreen.js';
 import Trail from '../util/Trail.js';
 import Utils from '../util/Utils.js';
-import WebGLBlock from '../display/WebGLBlock.js';
-import SafariWorkaroundOverlay from '../overlays/SafariWorkaroundOverlay.js';
-import { PDOM_UNIQUE_ID_SEPARATOR } from '../accessibility/pdom/PDOM_UNIQUE_ID_SEPARATOR.js';
 import DisplayGlobals from './DisplayGlobals.js';
-import HighlightVisibilityController from '../accessibility/HighlightVisibilityController.js';
-import Property from '../../../axon/js/Property.js';
 
 type SelfOptions = {
   // Initial (or override) display width
@@ -1624,8 +1624,8 @@
 
     function instanceCount( instance: Instance ): number {
       let count = 1; // for us
-      for ( let i = 0; i < instance.children.length; i++ ) {
-        count += instanceCount( instance.children[ i ] );
+      for ( let i = 0; i < instance.children!.length; i++ ) {
+        count += instanceCount( instance.children![ i ] as Instance );
       }
       return count;
     }
@@ -1680,8 +1680,8 @@
         countRetainedDrawable( instance.sharedCacheDrawable );
         count++;
       }
-      for ( let i = 0; i < instance.children.length; i++ ) {
-        count += retainedDrawableCount( instance.children[ i ] );
+      for ( let i = 0; i < instance.children!.length; i++ ) {
+        count += retainedDrawableCount( instance.children![ i ] as Instance );
       }
       return count;
     }
@@ -1866,7 +1866,7 @@
 
       depth += 1;
       _.each( instance.children, childInstance => {
-        printInstanceSubtree( childInstance );
+        printInstanceSubtree( childInstance as Instance );
       } );
       depth -= 1;
     }
Index: build-a-molecule/js/common/view/CollectionPanel.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/build-a-molecule/js/common/view/CollectionPanel.ts b/build-a-molecule/js/common/view/CollectionPanel.ts
--- a/build-a-molecule/js/common/view/CollectionPanel.ts	(revision f4402ef60ce7d34b559e5e0b5c1e54d01d7a65ad)
+++ b/build-a-molecule/js/common/view/CollectionPanel.ts	(date 1765253601851)
@@ -103,7 +103,9 @@
 
     // Update the arrows that indicate the next/previous collection
     const updateSwitcher = () => {
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       collectionSwitcher.hasNextProperty.value = bamModel.hasNextCollection();
+      // @ts-expect-error https://github.com/phetsims/chipper/issues/1651
       collectionSwitcher.hasPreviousProperty.value = bamModel.hasPreviousCollection();
     };
 
Index: quantum-measurement/js/coins/view/CoinsScreenView.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/quantum-measurement/js/coins/view/CoinsScreenView.ts b/quantum-measurement/js/coins/view/CoinsScreenView.ts
--- a/quantum-measurement/js/coins/view/CoinsScreenView.ts	(revision 04f0181a417e32538b45c84f5b4cd1d19cf06619)
+++ b/quantum-measurement/js/coins/view/CoinsScreenView.ts	(date 1765250896912)
@@ -6,7 +6,7 @@
  * @author John Blanco, PhET Interactive Simulations
  */
 
-import CoinsModel from 'model/CoinsModel.js';
+import CoinsModel from '../model/CoinsModel.js';
 import Multilink from '../../../../axon/js/Multilink.js';
 import Property from '../../../../axon/js/Property.js';
 import Bounds2 from '../../../../dot/js/Bounds2.js';
Index: phet-core/js/Poolable.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/phet-core/js/Poolable.ts b/phet-core/js/Poolable.ts
--- a/phet-core/js/Poolable.ts	(revision baf98423a2d17dd7993bc502f21bc12658c0dca6)
+++ b/phet-core/js/Poolable.ts	(date 1765251821558)
@@ -107,7 +107,7 @@
        * Returns an object with arbitrary state (possibly constructed with the default arguments).
        */
       dirtyFromPool(): PoolableVersion<Type> {
-        return pool.length ? pool.pop() : new DefaultConstructor();
+        return pool.length ? pool.pop() as PoolableVersion<Type> : new DefaultConstructor();
       },
 
       /**
Index: perennial/js/scripts/scenerystack-test.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial/js/scripts/scenerystack-test.ts b/perennial/js/scripts/scenerystack-test.ts
--- a/perennial/js/scripts/scenerystack-test.ts	(revision ff332d80b9406a11677826e7428f56dc1a4c8ab5)
+++ b/perennial/js/scripts/scenerystack-test.ts	(date 1765251916711)
@@ -211,6 +211,7 @@
 
     await viteBuild( './.scenerystack/demo-sim' );
 
+    // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
     const hasDisplay = await withServer( async port => {
       console.log( 'launching puppeteer' );
       return puppeteerEvaluate( `http://localhost:${port}/perennial/.scenerystack/demo-sim/dist/index.html`, '!!phet.joist.sim.display' );
@@ -258,6 +259,8 @@
       {
         console.log( `vite build ${repo}` );
         await viteBuild( `./.scenerystack/${repo}` );
+
+        // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
         await withServer( async port => {
           await puppeteerLoad( `http://localhost:${port}/perennial/.scenerystack/${repo}/dist/index.html` );
         } );
@@ -288,6 +291,8 @@
         console.log( `parcel build ${repo}` );
         await parcelBuild( `./.scenerystack/${repo}` );
         console.log( 'built' );
+
+        // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
         await withServer( async port => {
           await puppeteerLoad( `http://localhost:${port}/perennial/.scenerystack/${repo}/dist/index.html` );
         } );
Index: alpenglow/js/webgpu/compute/DeviceContext.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/alpenglow/js/webgpu/compute/DeviceContext.ts b/alpenglow/js/webgpu/compute/DeviceContext.ts
--- a/alpenglow/js/webgpu/compute/DeviceContext.ts	(revision 5be64327955d4e8fa6fa7fa3eef050aec77fff04)
+++ b/alpenglow/js/webgpu/compute/DeviceContext.ts	(date 1765251857545)
@@ -272,6 +272,8 @@
   }
 
   public static async getMappedArrayBuffer( buffer: GPUBuffer ): Promise<ArrayBuffer> {
+
+    // @ts-expect-error see https://github.com/phetsims/chipper/issues/1651
     return ( await DeviceContext.getMappedByteArray( buffer ) ).buffer;
   }
 }
Index: center-and-variability/js/variability/view/VariabilityPlotNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/center-and-variability/js/variability/view/VariabilityPlotNode.ts b/center-and-variability/js/variability/view/VariabilityPlotNode.ts
--- a/center-and-variability/js/variability/view/VariabilityPlotNode.ts	(revision cebb53ed2d9e66104efc62c54db1b65d5fb1c365)
+++ b/center-and-variability/js/variability/view/VariabilityPlotNode.ts	(date 1765253067159)
@@ -8,7 +8,7 @@
  * @author Sam Reid (PhET Interactive Simulations)
  */
 
-import NumberLineNode from '.../../../../soccer-common/js/view/NumberLineNode.js';
+import NumberLineNode from '../../../../soccer-common/js/view/NumberLineNode.js';
 import TProperty from '../../../../axon/js/TProperty.js';
 import { combineOptions } from '../../../../phet-core/js/optionize.js';
 import Node, { NodeOptions } from '../../../../scenery/js/nodes/Node.js';
Index: build-a-molecule/js/common/view/MoleculeControlsHBox.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/build-a-molecule/js/common/view/MoleculeControlsHBox.ts b/build-a-molecule/js/common/view/MoleculeControlsHBox.ts
--- a/build-a-molecule/js/common/view/MoleculeControlsHBox.ts	(revision f4402ef60ce7d34b559e5e0b5c1e54d01d7a65ad)
+++ b/build-a-molecule/js/common/view/MoleculeControlsHBox.ts	(date 1765253734989)
@@ -94,7 +94,6 @@
     } );
     buttonBreak.touchArea = buttonBreak.childBounds.dilated( DILATION_FACTOR );
 
-    // @ts-expect-error - see https://github.com/phetsims/build-a-molecule/issues/248
     buttonBreak.addInputListener( new ButtonListener( {
       fire: () => {
         kit.breakMolecule( molecule );
Index: balancing-act/js/game/model/BalanceGameModel.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/balancing-act/js/game/model/BalanceGameModel.ts b/balancing-act/js/game/model/BalanceGameModel.ts
--- a/balancing-act/js/game/model/BalanceGameModel.ts	(revision 6af8b8a67f72bef01f15d065475189c06cc0d150)
+++ b/balancing-act/js/game/model/BalanceGameModel.ts	(date 1765252771376)
@@ -54,7 +54,7 @@
   // Valid values for gameState are 'choosingLevel', 'presentingInteractiveChallenge', 'showingCorrectAnswerFeedback', 'showingIncorrectAnswerFeedbackTryAgain', 'showingIncorrectAnswerFeedbackMoveOn', 'displayingCorrectAnswer', 'showingLevelResults'
   public readonly gameStateProperty: Property<GameState>;
 
-  public readonly columnStateProperty: Property<typeof ColumnState>;
+  public readonly columnStateProperty: EnumerationDeprecatedProperty;
   public readonly elapsedTimeProperty: Property<number>;
 
   // Best times and scores

[samreid]

Also, there are some lint errors in the patch above

[samreid]

Also there are changes in 23 repos, so I didn't want to create 23 branches. A monorepo like discussed in #1242 or https://github.com/phetsims/bundle-pack-aero would have been interesting here.

[zepumph]

Please also coordinate with me, as website repos are type checking using perennial's script.

[samreid]

At today's dev meeting, we agreed to proceed. @zepumph and I will meet tomorrow to take it for a test drive and see if it is ready for main.

[samreid]

Proposed agenda for tomorrow's meeting:

• Generate "before" performance metrics on windows
• Apply the patch
• See if any other "band-aid" fixes are needed on a lint-everything with --clean.
• Update IDE settings (and instructions in setup.md)
• Generate "after" performance metrics
• Test "live editing" several files to see if the IDE is responsive and/or gets out of sync
• Discuss status and decide whether to commit to main. Note at the time we commit to main, we must notify developers to update typescript settings -- and this will remain a point of friction when working on release branches, until the settings normalize. (Could argue this is a reason to wait, so that in 6 months, when working on code from tomorrow, you don't have to change IDE typescript settings).
• Going over changes to the website codebase as well.

[zepumph]

Some notes from meeting with @samreid:

• tscClean() is a command shared between lint and type checking, and will need to support using both typescript versions (if we go down that road).
• A bit more effort could be spend trying to update javascript jsdoc instead of type casting or converting to typescript.
• Every time I ran with the tsgo and --clean, it gave an error that it failed to delete a single d.ts file: TS6353: Failed to delete file 'C:/Users/mjkauzmann/PHET/git/chipper/dist/tsc/outDir/axon/js/CallbackTimer.d.ts'.
• Splitting up the patch and committing what is possible before upgrading to 7 seems prudent. @samreid will start with 5.8, which will be quite simple, and then see if some of the larger changes, like conversions to typescript and work on EnumerationDeprecated can be separate commits.

In general we are still on the fence about when to do this. We found that the tsgo version changed, causing a type difference between today and when @samreid's patch was created. This amount of churn is expected for a project like this, but may cause trouble if we don't directly pin versions (because of npm update).

Timing numbers from initial experimentation (windows):

Context	Command	Version	Real time (s)
(root)	time grunt type-check --all --clean	5.7	467
(root)	time grunt type-check --all --clean	tsgo	71
number-pairs	time grunt type-check --clean	5.7	99
number-pairs	time grunt type-check --clean	tsgo	48
number-pairs	time grunt type-check	5.7	2.1
number-pairs	time grunt type-check	tsgo	1.8

[samreid]

Here is a patch that upgrades to TypeScript 5.9, which is supported by typescript-eslint (aside from import defer):

Details

Subject: [PATCH] Move the game button icons up a bit, see https://github.com/phetsims/number-pairs/issues/426
---
Index: phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts b/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts
--- a/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts	(revision 3cf1456b9addb7fc19cb6db8dbcdaab4bbcbb5d0)
+++ b/phet-io-wrappers/common/js/migration/processors/value-change-processors/composite-state-processors/RenameStateKeyTests.ts	(date 1768015320015)
@@ -198,7 +198,6 @@
 
       // Simplified example for the first test case
       class Dog extends PhetioObject {
-        // @ts-expect-error
         public [ attributeName ]: boolean;
 
         public constructor( hasLeash: boolean, public isHappyDoggo: boolean, public aSimplerHappiness: boolean, options: PhetioObjectOptions ) {
@@ -281,7 +280,6 @@
 
       // Simplified example for the first test case
       class Dog extends PhetioObject {
-        // @ts-expect-error
         public [ attributeName ]: boolean;
 
         public constructor( hasLeash: boolean, public isHappyDoggo: boolean, options: PhetioObjectOptions ) {
Index: perennial-alias/js/common/ReleaseBranch.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial-alias/js/common/ReleaseBranch.ts b/perennial-alias/js/common/ReleaseBranch.ts
--- a/perennial-alias/js/common/ReleaseBranch.ts	(revision 757511004dbea92b1ab78a24a17d9e9f93f3dc88)
+++ b/perennial-alias/js/common/ReleaseBranch.ts	(date 1768015256061)
@@ -50,7 +50,6 @@
 import simMetadata from './simMetadata.js';
 import simPhetioMetadata from './simPhetioMetadata.js';
 import withServer from './withServer.js';
-// @ts-expect-error
 import pLimit from 'p-limit';
 
 const MAINTENANCE_DIRECTORY = '../release-branches';
Index: perennial-alias/package.json
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial-alias/package.json b/perennial-alias/package.json
--- a/perennial-alias/package.json	(revision 757511004dbea92b1ab78a24a17d9e9f93f3dc88)
+++ b/perennial-alias/package.json	(date 1768014732252)
@@ -30,9 +30,9 @@
     "@types/three": "~0.137.0",
     "@types/nopt": "~3.0.32",
     "@webgpu/types": "~0.1.34",
-    "@typescript-eslint/eslint-plugin": "~8.28.0",
-    "@typescript-eslint/parser": "~8.28.0",
-    "@typescript-eslint/utils": "~8.28.0",
+    "@typescript-eslint/eslint-plugin": "~8.52.0",
+    "@typescript-eslint/parser": "~8.52.0",
+    "@typescript-eslint/utils": "~8.52.0",
     "async": "~0.9.2",
     "async-mutex": "~0.4.0",
     "async-q": "~0.3.1",
@@ -63,7 +63,7 @@
     "thread-sleep": "~2.0.0",
     "ts-morph": "~21.0.1",
     "tsx": "~4.19.1",
-    "typescript": "~5.7.2",
+    "typescript": "~5.9.3",
     "winston": "~2.4.5",
     "winston-loggly": "~1.3.1",
     "xml2js": "~0.4.15"
Index: alpenglow/js/webgpu/WebGPURecorder.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/alpenglow/js/webgpu/WebGPURecorder.ts b/alpenglow/js/webgpu/WebGPURecorder.ts
--- a/alpenglow/js/webgpu/WebGPURecorder.ts	(revision 5be64327955d4e8fa6fa7fa3eef050aec77fff04)
+++ b/alpenglow/js/webgpu/WebGPURecorder.ts	(date 1768015512584)
@@ -302,8 +302,10 @@
   }
 
   // TODO: consider how we're handling this
-  public static arrayBufferLikeString( data: ArrayLike<number> | ArrayBufferLike ): string {
-    return `new Uint8Array( [ ${new Uint8Array( data ).join( ', ' )} ] ).buffer`;
+  public static arrayBufferLikeString( data: ArrayLike<number> | ArrayBuffer | SharedArrayBuffer ): string {
+
+    // Cast needed because TypeScript's Uint8Array overloads don't include SharedArrayBuffer
+    return `new Uint8Array( [ ${new Uint8Array( data as ArrayBuffer ).join( ', ' )} ] ).buffer`;
   }
 
   public static objectToString(
Index: perennial/js/common/ReleaseBranch.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/perennial/js/common/ReleaseBranch.ts b/perennial/js/common/ReleaseBranch.ts
--- a/perennial/js/common/ReleaseBranch.ts	(revision 757511004dbea92b1ab78a24a17d9e9f93f3dc88)
+++ b/perennial/js/common/ReleaseBranch.ts	(date 1768015265867)
@@ -50,7 +50,6 @@
 import simMetadata from './simMetadata.js';
 import simPhetioMetadata from './simPhetioMetadata.js';
 import withServer from './withServer.js';
-// @ts-expect-error
 import pLimit from 'p-limit';
 
 const MAINTENANCE_DIRECTORY = '../release-branches';
Index: circuit-construction-kit-common/js/model/analysis/spice/SpiceLoader.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/circuit-construction-kit-common/js/model/analysis/spice/SpiceLoader.ts b/circuit-construction-kit-common/js/model/analysis/spice/SpiceLoader.ts
--- a/circuit-construction-kit-common/js/model/analysis/spice/SpiceLoader.ts	(revision 08f4bbc476a03cd6e22c7e73f43d4e4df1b3b31d)
+++ b/circuit-construction-kit-common/js/model/analysis/spice/SpiceLoader.ts	(date 1768015428962)
@@ -22,7 +22,7 @@
 
 // Create blob URL for WASM
 const wasmBytes = base64ToArrayBuffer( NGSPICE_WASM_BASE64 );
-const wasmBlob = new Blob( [ wasmBytes ], { type: 'application/wasm' } );
+const wasmBlob = new Blob( [ wasmBytes as BlobPart ], { type: 'application/wasm' } );
 const wasmUrl = URL.createObjectURL( wasmBlob );
 
 type ModuleArg = {
Index: phet-core/js/Poolable.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/phet-core/js/Poolable.ts b/phet-core/js/Poolable.ts
--- a/phet-core/js/Poolable.ts	(revision 6588af4794051c43cc419fbad2cb15ed2377294a)
+++ b/phet-core/js/Poolable.ts	(date 1768015125139)
@@ -107,7 +107,7 @@
        * Returns an object with arbitrary state (possibly constructed with the default arguments).
        */
       dirtyFromPool(): PoolableVersion<Type> {
-        return pool.length ? pool.pop() : new DefaultConstructor();
+        return pool.length ? pool.pop() as PoolableVersion<Type> : new DefaultConstructor();
       },
 
       /**
Index: alpenglow/js/webgpu/compute/DeviceContext.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/alpenglow/js/webgpu/compute/DeviceContext.ts b/alpenglow/js/webgpu/compute/DeviceContext.ts
--- a/alpenglow/js/webgpu/compute/DeviceContext.ts	(revision 5be64327955d4e8fa6fa7fa3eef050aec77fff04)
+++ b/alpenglow/js/webgpu/compute/DeviceContext.ts	(date 1768015186751)
@@ -271,7 +271,7 @@
     return outputArray;
   }
 
-  public static async getMappedArrayBuffer( buffer: GPUBuffer ): Promise<ArrayBuffer> {
+  public static async getMappedArrayBuffer( buffer: GPUBuffer ): Promise<ArrayBufferLike> {
     return ( await DeviceContext.getMappedByteArray( buffer ) ).buffer;
   }
 }
Index: alpenglow/js/webgpu/compute/BufferLogger.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/alpenglow/js/webgpu/compute/BufferLogger.ts b/alpenglow/js/webgpu/compute/BufferLogger.ts
--- a/alpenglow/js/webgpu/compute/BufferLogger.ts	(revision 5be64327955d4e8fa6fa7fa3eef050aec77fff04)
+++ b/alpenglow/js/webgpu/compute/BufferLogger.ts	(date 1768015428861)
@@ -45,7 +45,7 @@
     this.callbacksOnComplete.push( async () => {
       const arrayBuffer = await DeviceContext.getMappedArrayBuffer( mappableBuffer );
 
-      await callback( arrayBuffer );
+      await callback( arrayBuffer as ArrayBuffer );
 
       webgpu.bufferDestroy( mappableBuffer );
     } );