Fix: populate resultSegments in method.response for @markAsPageable

[Copilot]

• Review existing tests for paged operations to understand expected behavior
• Identify the fix location in methods.ts where @markAsPageable is handled
• Add missing baseServiceMethod.response.resultSegments assignment for @markAsPageable case
• Add test case to verify resultSegments is populated when using @markAsPageable
• Build project and run tests to verify the fix works correctly
• Run full test suite for mark-as-pageable and paged-operation tests (40 tests passed)
• Run linter to ensure code style is correct (no issues found)
• Run code review (no issues found)
• Add resultSegments assertions to all applicable tests in mark-as-pageable.test.ts
• Remove "issue fix" notes from test comments
• Add changeset for the fix
• Add context.__pagedResultSet.add(responseType) call for @markAsPageable to match normal paging behavior
• Fix build error by adding null check for responseType
• Add test for isPagedResultModel with @markAsPageable decorator
• Fix formatting issues reported in CI

Original prompt

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This section details on the original issue you should resolve

<issue_title>[TCGC] resultSegments is not populated in method.response when there is a @markAsPageable decorator</issue_title>
<issue_description>In a regular pageable operation, the method.response.resultSegments should contain the array of properties to walk to get the actual results from the actual response model.
When we make a method as pageable via the decorator, the experience should be exactly the same.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [TCGC] resultSegments is not populated in method.response when there is a @markAsPageable decorator #3799

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[ArcturusZhang]

@copilot please resolve the comment and add a changeset

[Copilot]

@copilot please resolve the comment and add a changeset

Resolved the comment and added changeset in commit ed4a191. The changeset documents this as a fix to populate method.response.resultSegments for the @markAsPageable decorator.

[ArcturusZhang]

@copilot please fix the build error

[Copilot]

@copilot please fix the build error

Fixed the build error in commit 28d90c5 by adding a null check for responseType before adding it to __pagedResultSet. The responseType can be undefined in some cases, so we now only add it to the set when it's defined.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/Azure/typespec-azure/@azure-tools/typespec-client-generator-core@3800

commit: de972e8

[ArcturusZhang]

@copilot fix the format issue reported in CI

[Copilot]

@copilot fix the format issue reported in CI

Fixed formatting issue in commit c8bb523 by removing the trailing blank line from the is-paged-result-model.test.ts file.