refactor(github): move inline PR comment line placement to src/shared (#36904)

src/renderer/src/components/github-item-dialog/inspect-pull-request/pr-files-combined-diff-viewer.tsx

@@ -1,7 +1,6 @@
 import React, { useCallback, useLayoutEffect, useMemo, useRef, useState } from 'react'
 import { useVirtualizer } from '@tanstack/react-virtual'
 import type { editor as monacoEditor } from 'monaco-editor'
-import type { DecoratedDiffComment } from '@/components/diff-comments/decorated-diff-comment'
 import { useCombinedDiffSectionIndexMap } from '../../editor/combined-diff/resolve-changes/use-combined-diff-section-index-map'
 import { handleCombinedDiffFileTreeNavigation } from '../../editor/combined-diff/browse-files/combined-diff-file-tree-navigation'
 import { getDiffSectionRowEstimatedHeight } from '@/components/editor/diff-section-layout'
@@ -18,7 +17,7 @@ import {
   gitHubPRFileToBranchEntry,
   type PRFilesCombinedDiffViewerProps
 } from '@/components/github/pr-file-diff-mapping'
-import { formatRelativeTime } from '@/components/github/work-item-state-presentation'
+import { buildInlineReviewComments } from '@/components/pull-request-page/files/inline-comments'
 import { PRViewedCheckbox } from '@/components/github/PRViewedCheckbox'
 import { PRFilesCombinedDiffBody } from './pr-files-combined-diff-body'
 import { getPRFilesCombinedDiffSignature } from './pr-files-combined-diff-signature'
@@ -123,34 +122,8 @@ function PRFilesCombinedDiffSections({
       fileByPath.get(section.path)?.reviewCommentLineNumbers,
     [fileByPath]
   )
-  const inlineReviewComments = useMemo<DecoratedDiffComment[]>(
-    () =>
-      comments.flatMap((comment): DecoratedDiffComment[] => {
-        // Why: outdated threads' line number can attach the comment to unrelated current code, so skip them inline.
-        if (comment.isOutdated || !comment.path || typeof comment.line !== 'number') {
-          return []
-        }
-        const createdAtMs = new Date(comment.createdAt).getTime()
-        return [
-          {
-            id: `github-pr-comment:${comment.id}`,
-            worktreeId: `github-pr:${repoId}:${prNumber}`,
-            filePath: comment.path,
-            source: 'diff',
-            startLine: comment.startLine,
-            lineNumber: comment.line,
-            body: comment.body,
-            createdAt: Number.isFinite(createdAtMs) ? createdAtMs : Date.now(),
-            side: 'modified',
-            author: comment.author,
-            authorAvatarUrl: comment.authorAvatarUrl,
-            createdAtLabel: formatRelativeTime(comment.createdAt),
-            url: comment.url,
-            canDelete: false,
-            canEdit: false
-          }
-        ]
-      }),
+  const inlineReviewComments = useMemo(
+    () => buildInlineReviewComments(comments, repoId, prNumber),
     [comments, prNumber, repoId]
   )
   const [sectionHeights, setSectionHeights] = useState<Record<number, number>>({})

src/renderer/src/components/pull-request-page/files/inline-comments.ts

@@ -1,6 +1,7 @@
 import type { DecoratedDiffComment } from '@/components/diff-comments/decorated-diff-comment'
 import { formatRelativeTime } from '@/components/github/work-item-state-presentation'
 import type { PRComment } from '../../../../../shared/github/comment-types'
+import { getPRInlineCommentPlacement } from '../../../../../shared/github/pr-inline-comment-placement'
 
 export function buildInlineReviewComments(
   comments: PRComment[],
@@ -8,8 +9,8 @@ export function buildInlineReviewComments(
   prNumber: number
 ): DecoratedDiffComment[] {
   return comments.flatMap((comment): DecoratedDiffComment[] => {
-    // Why: outdated threads keep originalLine for the sidebar, but rendering it inline can attach the comment to unrelated current code.
-    if (comment.isOutdated || !comment.path || typeof comment.line !== 'number') {
+    const placement = getPRInlineCommentPlacement(comment)
+    if (!placement) {
       return []
     }
     const createdAtMs = new Date(comment.createdAt).getTime()
@@ -17,10 +18,10 @@ export function buildInlineReviewComments(
       {
         id: `github-pr-comment:${comment.id}`,
         worktreeId: `github-pr:${repoId}:${prNumber}`,
-        filePath: comment.path,
+        filePath: placement.path,
         source: 'diff',
-        startLine: comment.startLine,
-        lineNumber: comment.line,
+        startLine: placement.startLine,
+        lineNumber: placement.line,
         body: comment.body,
         createdAt: Number.isFinite(createdAtMs) ? createdAtMs : Date.now(),
         side: 'modified',

src/shared/github/pr-inline-comment-placement.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest'
+import type { PRComment } from './comment-types'
+import { getPRInlineCommentPlacement } from './pr-inline-comment-placement'
+
+const comment = (overrides: Partial<PRComment>): PRComment => ({
+  id: 1,
+  author: 'octocat',
+  authorAvatarUrl: '',
+  body: 'body',
+  createdAt: '2026-11-01T00:00:00Z',
+  url: 'https://github.com/o/r/pull/1#discussion_r1',
+  ...overrides
+})
+
+describe('getPRInlineCommentPlacement', () => {
+  it('places a current review comment on its range', () => {
+    expect(
+      getPRInlineCommentPlacement(comment({ path: 'src/a.ts', line: 12, startLine: 10 }))
+    ).toEqual({ path: 'src/a.ts', line: 12, startLine: 10 })
+  })
+
+  it('keeps outdated threads and conversation comments out of the diff', () => {
+    expect(
+      getPRInlineCommentPlacement(comment({ path: 'src/a.ts', line: 12, isOutdated: true }))
+    ).toBeNull()
+    expect(getPRInlineCommentPlacement(comment({ path: 'src/a.ts' }))).toBeNull()
+    expect(getPRInlineCommentPlacement(comment({}))).toBeNull()
+  })
+})

src/shared/github/pr-inline-comment-placement.ts

@@ -0,0 +1,16 @@
+import type { PRComment } from './comment-types'
+
+export type PRInlineCommentPlacement = {
+  path: string
+  line: number
+  startLine: number | undefined
+}
+
+/** Where a PR review comment sits in the current diff, or null when it should not render inline. */
+export function getPRInlineCommentPlacement(comment: PRComment): PRInlineCommentPlacement | null {
+  // Why: outdated threads keep originalLine for the sidebar, but rendering it inline can attach the comment to unrelated current code.
+  if (comment.isOutdated || !comment.path || typeof comment.line !== 'number') {
+    return null
+  }
+  return { path: comment.path, line: comment.line, startLine: comment.startLine }
+}