feed: open links in new files

AGENTS.md

@@ -128,7 +128,54 @@ func TestExample(t *testing.T) {
 }
 ```
 
+## Markdown Rendering
+
+### Architecture
+- **Library**: goldmark (extensible markdown parser)
+- **Location**: `pkg/markdown/`
+- **Entry point**: `ToEnrichedTemplate()` in `pkg/markdown/html.go`
+
+### View Types
+Defined in `pkg/types/types.go`:
+- `ViewFeed` - RSS feed items (links open in new tab)
+- `ViewSinglePost` - Individual post view
+- `ViewEditPreview` - Post editor preview
+- `ViewComment` - Comment rendering
+- `ViewArticle` - Article view
+- `ViewEmail` - Email notifications
+- `ViewRSS` - RSS feed output
+
+### Template Functions
+Defined in `cmd/web/main.go` funcmap:
+- `markdown_feed` - Renders feed items with `ViewFeed`
+- `markdown_single_post` - Renders posts with `ViewSinglePost`
+- `markdown_edit_preview` - Renders editor preview with `ViewEditPreview`
+- `markdown_comment` - Renders comments with `ViewComment`
+- `markdown_article` - Renders articles with `ViewArticle`
+
+### Custom Renderers
+Located in `pkg/markdown/mdext/`:
+- **linkrenderer** - Custom link renderer, adds `target="_blank" rel="noopener noreferrer"` for `ViewFeed`
+- **lazyload** - Lazy loading for images
+- **blocktags** - Custom block tags (gallery, etc.)
+- **headershift** - Shifts header levels (h1→h2, etc.)
+- **videoembed** - Embeds videos from URLs
+- **handle** - Renders @username mentions
+
+### Extensions
+Configured in `NewParser()`:
+- **Linkify** - Auto-converts URLs to links (custom regex excludes closing braces)
+- **Syntax highlighting** - Only for feed, single post, and edit preview views
+- Custom node renderers registered via `util.Prioritized()` with priority 500
+
+### Adding Custom Renderers
+1. Create renderer in `pkg/markdown/mdext/<name>/`
+2. Implement `renderer.NodeRenderer` interface with `RegisterFuncs()`
+3. Register in `NewParser()` via `nodeRenderers` slice
+4. Conditionally add based on view type if needed
+
 ## File Locations
 - HTML Templates: `/Users/dima/code/pcom/cmd/web/client/html/`
 - JavaScript: `/Users/dima/code/pcom/cmd/web/client/js/`
 - Main JS entry: `/Users/dima/code/pcom/cmd/web/client/js/index.js`
+- Markdown package: `/Users/dima/code/pcom/pkg/markdown/`

pkg/markdown/html.go

@@ -10,6 +10,7 @@ import (
 	"github.com/can3p/pcom/pkg/markdown/mdext/blocktags"
 	"github.com/can3p/pcom/pkg/markdown/mdext/headershift"
 	"github.com/can3p/pcom/pkg/markdown/mdext/lazyload"
+	"github.com/can3p/pcom/pkg/markdown/mdext/linkrenderer"
 	"github.com/can3p/pcom/pkg/markdown/mdext/videoembed"
 	"github.com/can3p/pcom/pkg/types"
 	"github.com/yuin/goldmark"
@@ -69,6 +70,11 @@ func NewParser(view types.HTMLView, mediaReplacer types.Replacer[string], link t
 			}), 500),
 	}
 
+	// Add custom link renderer for RSS feed view to open links in new tab
+	if view == types.ViewFeed {
+		nodeRenderers = append(nodeRenderers, util.Prioritized(linkrenderer.NewLinkRenderer(true), 500))
+	}
+
 	if view == types.ViewEditPreview || view == types.ViewFeed || view == types.ViewSinglePost || view == types.ViewEmail || view == types.ViewRSS {
 		extensions = append(extensions, blocktags.NewBlockTagExtender(view, link))
 	}

pkg/markdown/html_test.go

@@ -0,0 +1,143 @@
+package markdown
+
+import (
+	"testing"
+
+	"github.com/can3p/pcom/pkg/types"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFeedViewLinksOpenInNewTab(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		contains []string
+	}{
+		{
+			name:  "regular markdown link",
+			input: "[example](https://example.com)",
+			contains: []string{
+				`<a href="https://example.com" target="_blank" rel="noopener noreferrer">example</a>`,
+			},
+		},
+		{
+			name:  "autolinked URL",
+			input: "Check out https://example.com for more info",
+			contains: []string{
+				`<a href="https://example.com" target="_blank" rel="noopener noreferrer">https://example.com</a>`,
+			},
+		},
+		{
+			name:  "link with title",
+			input: `[example](https://example.com "Example Site")`,
+			contains: []string{
+				`<a href="https://example.com" title="Example Site" target="_blank" rel="noopener noreferrer">example</a>`,
+			},
+		},
+		{
+			name:  "multiple links",
+			input: "[first](https://first.com) and [second](https://second.com)",
+			contains: []string{
+				`<a href="https://first.com" target="_blank" rel="noopener noreferrer">first</a>`,
+				`<a href="https://second.com" target="_blank" rel="noopener noreferrer">second</a>`,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := ToEnrichedTemplate(tt.input, types.ViewFeed, func(in string) (bool, string) {
+				return false, in
+			}, func(name string, args ...string) string {
+				return "/" + name
+			})
+
+			output := string(result)
+			for _, expected := range tt.contains {
+				assert.Contains(t, output, expected, "Output should contain expected HTML")
+			}
+		})
+	}
+}
+
+func TestNonFeedViewLinksDoNotOpenInNewTab(t *testing.T) {
+	tests := []struct {
+		name string
+		view types.HTMLView
+	}{
+		{
+			name: "single post view",
+			view: types.ViewSinglePost,
+		},
+		{
+			name: "edit preview view",
+			view: types.ViewEditPreview,
+		},
+		{
+			name: "comment view",
+			view: types.ViewComment,
+		},
+	}
+
+	input := "[example](https://example.com)"
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := ToEnrichedTemplate(input, tt.view, func(in string) (bool, string) {
+				return false, in
+			}, func(name string, args ...string) string {
+				return "/" + name
+			})
+
+			output := string(result)
+			// Should NOT contain target="_blank"
+			assert.NotContains(t, output, `target="_blank"`, "Non-feed views should not open links in new tab")
+			// Should still contain the link
+			assert.Contains(t, output, `<a href="https://example.com">example</a>`, "Should contain regular link")
+		})
+	}
+}
+
+func TestFeedViewPreservesOtherMarkdownFeatures(t *testing.T) {
+	input := `# Heading
+
+This is a paragraph with a [link](https://example.com).
+
+- List item 1
+- List item 2
+
+**Bold text** and *italic text*.`
+
+	result := ToEnrichedTemplate(input, types.ViewFeed, func(in string) (bool, string) {
+		return false, in
+	}, func(name string, args ...string) string {
+		return "/" + name
+	})
+
+	output := string(result)
+
+	// Verify link has target="_blank"
+	assert.Contains(t, output, `target="_blank"`)
+
+	// Verify other markdown features are preserved
+	assert.Contains(t, output, `<h2>Heading</h2>`) // h2 because of header shift
+	assert.Contains(t, output, `<ul>`)
+	assert.Contains(t, output, `<li>List item 1</li>`)
+	assert.Contains(t, output, `<strong>Bold text</strong>`)
+	assert.Contains(t, output, `<em>italic text</em>`)
+}
+
+func TestFeedViewEmailAutolink(t *testing.T) {
+	input := "<user@example.com>"
+
+	result := ToEnrichedTemplate(input, types.ViewFeed, func(in string) (bool, string) {
+		return false, in
+	}, func(name string, args ...string) string {
+		return "/" + name
+	})
+
+	output := string(result)
+
+	// Email links should also open in new tab
+	assert.Contains(t, output, `<a href="mailto:user@example.com" target="_blank" rel="noopener noreferrer">user@example.com</a>`)
+}

pkg/markdown/mdext/linkrenderer/link_renderer.go

@@ -0,0 +1,74 @@
+package linkrenderer
+
+import (
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/util"
+)
+
+type LinkRenderer struct {
+	html.Config
+	openInNewTab bool
+}
+
+func NewLinkRenderer(openInNewTab bool, opts ...html.Option) renderer.NodeRenderer {
+	r := &LinkRenderer{
+		Config:       html.NewConfig(),
+		openInNewTab: openInNewTab,
+	}
+	for _, opt := range opts {
+		opt.SetHTMLOption(&r.Config)
+	}
+	return r
+}
+
+func (r *LinkRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(ast.KindLink, r.renderLink)
+	reg.Register(ast.KindAutoLink, r.renderAutoLink)
+}
+
+func (r *LinkRenderer) renderLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*ast.Link)
+	if entering {
+		_, _ = w.WriteString("<a href=\"")
+		if r.Unsafe || !html.IsDangerousURL(n.Destination) {
+			_, _ = w.Write(util.EscapeHTML(util.URLEscape(n.Destination, true)))
+		}
+		_ = w.WriteByte('"')
+		if n.Title != nil {
+			_, _ = w.WriteString(` title="`)
+			r.Writer.Write(w, n.Title)
+			_ = w.WriteByte('"')
+		}
+		if r.openInNewTab {
+			_, _ = w.WriteString(` target="_blank" rel="noopener noreferrer"`)
+		}
+		_ = w.WriteByte('>')
+	} else {
+		_, _ = w.WriteString("</a>")
+	}
+	return ast.WalkContinue, nil
+}
+
+func (r *LinkRenderer) renderAutoLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*ast.AutoLink)
+	if !entering {
+		return ast.WalkContinue, nil
+	}
+	_, _ = w.WriteString("<a href=\"")
+	url := n.URL(source)
+	label := n.Label(source)
+	if n.AutoLinkType == ast.AutoLinkEmail && len(url) >= 7 && string(url[:7]) != "mailto:" {
+		_, _ = w.WriteString("mailto:")
+	}
+	_, _ = w.Write(util.EscapeHTML(util.URLEscape(url, false)))
+	if r.openInNewTab {
+		_, _ = w.WriteString(`" target="_blank" rel="noopener noreferrer">`)
+	} else {
+		_, _ = w.WriteString(`">`)
+	}
+	_, _ = w.Write(util.EscapeHTML(label))
+	_, _ = w.WriteString("</a>")
+	return ast.WalkContinue, nil
+}