fix(github): merge successful posts into fetched comment history (#35306)

* fix(github): preserve posted comments across older reads

* fix(github): allow comment reads after cache eviction

* fix(github): merge in-flight posts into fetched comment history

* test(github): trim PR comment read-order tests

---------

Co-authored-by: OrcaWin <293788423+OrcaWin@users.noreply.github.com>

src/renderer/src/store/github/comment-fetch-actions.ts

@@ -6,6 +6,7 @@ import { callRuntimeRpc } from '../../runtime/runtime-rpc-client'
 import { prCommentsCacheSuffix, sourceScopedRepoCacheKey } from './cache-identity'
 import { isFresh, withBoundedCacheEntry } from './cache-policy'
 import { inflightCommentsRequests } from './request-coordination'
+import { mergePRCommentIntoList } from './pr-comment-cache'
 import {
   getGitHubRepoSourceSettings,
   getGitHubSourceTarget,
@@ -39,9 +40,10 @@ export const createCommentFetchActions = (
 
     const inflightRequest = inflightCommentsRequests.get(cacheKey)
     if (inflightRequest) {
-      return inflightRequest
+      return inflightRequest.promise
     }
 
+    const postedComments: PRComment[] = []
     const request = (async () => {
       try {
         const requestContext = getGitHubWorkItemRequestContext(
@@ -51,7 +53,7 @@ export const createCommentFetchActions = (
           repoPath,
           options?.sourceContext
         )
-        const comments =
+        let comments: PRComment[] =
           requestContext.target.kind === 'environment'
             ? await callRuntimeRpc<PRComment[]>(
                 { kind: 'environment', environmentId: requestContext.target.environmentId },
@@ -64,14 +66,22 @@ export const createCommentFetchActions = (
                 },
                 { timeoutMs: 30_000 }
               )
-            : ((await window.api.gh.prComments({
+            : await window.api.gh.prComments({
                 repoPath,
                 repoId,
                 prNumber,
                 prRepo: options?.prRepo ?? null,
                 noCache: options?.force,
                 sourceContext: options?.sourceContext
-              })) as PRComment[])
+              })
+        if (postedComments.length > 0) {
+          const currentById = new Map(
+            (get().commentsCache[cacheKey]?.data ?? []).map((comment) => [comment.id, comment])
+          )
+          for (const posted of postedComments) {
+            comments = mergePRCommentIntoList(comments, currentById.get(posted.id) ?? posted)
+          }
+        }
         set((s) => ({
           commentsCache: withBoundedCacheEntry(s.commentsCache, cacheKey, {
             data: comments,
@@ -87,7 +97,7 @@ export const createCommentFetchActions = (
       }
     })()
 
-    inflightCommentsRequests.set(cacheKey, request)
+    inflightCommentsRequests.set(cacheKey, { promise: request, postedComments })
     return request
   }
 })

src/renderer/src/store/github/comment-mutation-actions.ts

@@ -8,6 +8,7 @@ import { restoreReactionOnSubject, setReactionOnSubject } from '@/lib/pr-comment
 import { prCommentsCacheSuffix, sourceScopedRepoCacheKey } from './cache-identity'
 import { withBoundedCacheEntry } from './cache-policy'
 import { hasUsableCommentPayload, mergePRCommentIntoList } from './pr-comment-cache'
+import { inflightCommentsRequests } from './request-coordination'
 import {
   getGitHubRepoSourceSettings,
   getGitHubSourceTarget,
@@ -102,6 +103,7 @@ export const createCommentMutationActions = (
         })
       }
     })
+    inflightCommentsRequests.get(cacheKey)?.postedComments.push(comment)
     return { ok: true, comment }
   },
 

src/renderer/src/store/github/conversation-comment-actions.ts

@@ -7,6 +7,7 @@ import { callRuntimeRpc } from '../../runtime/runtime-rpc-client'
 import { prCommentsCacheSuffix, sourceScopedRepoCacheKey } from './cache-identity'
 import { withBoundedCacheEntry } from './cache-policy'
 import { hasUsableCommentPayload, mergePRCommentIntoList } from './pr-comment-cache'
+import { inflightCommentsRequests } from './request-coordination'
 import {
   getGitHubRepoSourceSettings,
   getGitHubSourceTarget,
@@ -89,6 +90,7 @@ export const createConversationCommentActions = (
         })
       }
     })
+    inflightCommentsRequests.get(cacheKey)?.postedComments.push(result.comment)
     return result
   }
 })

src/renderer/src/store/github/request-coordination.ts

@@ -20,6 +20,10 @@ export type InflightChecks = {
   /** A user act's request may start a stopped WSL distro; a poll's would be refused. */
   wakeWslDistro?: boolean
 }
+export type InflightComments = {
+  promise: Promise<PRComment[]>
+  postedComments: PRComment[]
+}
 export type InflightWorkItems = {
   promise: Promise<readonly GitHubWorkItem[]>
   requestId: number
@@ -37,7 +41,7 @@ export type InflightProjectView = {
 export const inflightPRRequests = new Map<string, InflightPR>()
 export const inflightIssueRequests = new Map<string, Promise<IssueInfo | null>>()
 export const inflightChecksRequests = new Map<string, InflightChecks>()
-export const inflightCommentsRequests = new Map<string, Promise<PRComment[]>>()
+export const inflightCommentsRequests = new Map<string, InflightComments>()
 export const inflightWorkItemsRequests = new Map<string, InflightWorkItems>()
 export const inflightProjectViewRequests = new Map<string, InflightProjectView>()
 export const prRequestGenerations = new Map<string, number>()

src/renderer/src/store/slices/github-pr-comment-read-order.test.ts

@@ -0,0 +1,85 @@
+import { beforeEach, expect, it, vi } from 'vitest'
+import type { PRComment } from '../../../../shared/github/comment-types'
+import { createTestStore, mockApi, resetRemoteRuntimeMocks } from './github-slice-test-harness'
+
+const repoPath = '/repo'
+const repoId = 'comment-race-repo'
+const prRepo = { owner: 'Acme', repo: 'Widgets' }
+const options = { repoId, prRepo }
+const cacheKey = `${repoId}::pr-comments::acme/widgets::12`
+const original: PRComment = {
+  id: 10,
+  author: 'reviewer',
+  authorAvatarUrl: '',
+  body: 'Before',
+  createdAt: '2026-10-28T00:00:00Z',
+  url: ''
+}
+const posted: PRComment = {
+  ...original,
+  id: 11,
+  reactionSubjectId: 'IC_11',
+  body: 'Posted reply',
+  createdAt: '2026-10-28T00:01:00Z'
+}
+const remoteAdded: PRComment = {
+  ...original,
+  id: 12,
+  body: 'Another reviewer posted this',
+  createdAt: '2026-10-28T00:00:30Z'
+}
+
+function makeStore(cached = true) {
+  const store = createTestStore()
+  store.setState({
+    repos: [{ id: repoId, path: repoPath, displayName: 'Repo', badgeColor: '#000', addedAt: 0 }],
+    commentsCache: cached ? { [cacheKey]: { data: [original], fetchedAt: 1 } } : {}
+  })
+  return store
+}
+
+beforeEach(() => {
+  vi.clearAllMocks()
+  resetRemoteRuntimeMocks()
+  mockApi.gh.addIssueComment.mockResolvedValue({ ok: true, comment: posted })
+  mockApi.gh.addPRReviewCommentReply.mockResolvedValue({ ok: true, comment: posted })
+})
+
+it.each([
+  ['comment', true],
+  ['comment', false],
+  ['reply', true],
+  ['reply', false]
+] as const)('merges a posted %s with complete history with cached=%s', async (kind, cached) => {
+  const store = makeStore(cached)
+  const oldRead = Promise.withResolvers<PRComment[]>()
+  mockApi.gh.prComments.mockReturnValueOnce(oldRead.promise)
+  const reading = store.getState().fetchPRComments(repoPath, 12, { ...options, force: true })
+  const result =
+    kind === 'comment'
+      ? await store.getState().addPRConversationComment(repoPath, 12, posted.body, options)
+      : await store.getState().addPRReviewCommentReply(repoPath, 12, 10, posted.body, options)
+  expect(result.ok).toBe(true)
+  const published = store.getState().commentsCache[cacheKey]
+  expect(published?.data?.map(({ id }) => id)).toEqual(cached ? [10, 11] : [11])
+  oldRead.resolve([original, remoteAdded])
+  await expect(reading).resolves.toEqual([original, remoteAdded, posted])
+  expect(store.getState().commentsCache[cacheKey]?.data).toEqual([original, remoteAdded, posted])
+})
+
+it('keeps a successful reaction on a newly posted reply while adding fetched history', async () => {
+  const store = makeStore(false)
+  const oldRead = Promise.withResolvers<PRComment[]>()
+  mockApi.gh.prComments.mockReturnValueOnce(oldRead.promise)
+  mockApi.gh.setPRCommentReaction.mockResolvedValueOnce(true)
+  const reading = store.getState().fetchPRComments(repoPath, 12, { ...options, force: true })
+  await store.getState().addPRReviewCommentReply(repoPath, 12, 10, posted.body, options)
+  await store.getState().setPRCommentReaction(repoPath, 12, 'IC_11', 'heart', true, options)
+  oldRead.resolve([original, remoteAdded])
+  const displayed = await reading
+  expect(displayed.map(({ id }) => id)).toEqual([10, 12, 11])
+  expect(displayed.find(({ id }) => id === posted.id)?.reactions).toEqual([
+    { content: 'heart', count: 1, viewerHasReacted: true }
+  ])
+  expect(store.getState().commentsCache[cacheKey]?.data).toEqual(displayed)
+})