fix(app): diff list normalization

5 files changed, 136 insertions, 14 deletions

diff --git a/packages/app/src/context/global-sync/event-reducer.ts b/packages/app/src/context/global-sync/event-reducer.ts
index 01248e20e..500013c1d 100644
--- a/packages/app/src/context/global-sync/event-reducer.ts
+++ b/packages/app/src/context/global-sync/event-reducer.ts
@@ -14,6 +14,7 @@ import type {
 import type { State, VcsCache } from "./types"
 import { trimSessions } from "./session-trim"
 import { dropSessionCaches } from "./session-cache"
+import { diffs as list, message as clean } from "@/utils/diffs"
 
 const SKIP_PARTS = new Set(["patch", "step-start", "step-finish"])
 
@@ -162,7 +163,7 @@ export function applyDirectoryEvent(input: {
     }
     case "session.diff": {
       const props = event.properties as { sessionID: string; diff: SnapshotFileDiff[] }
-      input.setStore("session_diff", props.sessionID, reconcile(props.diff, { key: "file" }))
+      input.setStore("session_diff", props.sessionID, reconcile(list(props.diff), { key: "file" }))
       break
     }
     case "todo.updated": {
@@ -177,7 +178,7 @@ export function applyDirectoryEvent(input: {
       break
     }
     case "message.updated": {
-      const info = (event.properties as { info: Message }).info
+      const info = clean((event.properties as { info: Message }).info)
       const messages = input.store.message[info.sessionID]
       if (!messages) {
         input.setStore("message", info.sessionID, [info])
diff --git a/packages/app/src/context/sync.tsx b/packages/app/src/context/sync.tsx
index b023e8ddc..fb02a2d2d 100644
--- a/packages/app/src/context/sync.tsx
+++ b/packages/app/src/context/sync.tsx
@@ -13,6 +13,7 @@ import { useGlobalSync } from "./global-sync"
 import { useSDK } from "./sdk"
 import type { Message, Part } from "@opencode-ai/sdk/v2/client"
 import { SESSION_CACHE_LIMIT, dropSessionCaches, pickSessionCacheEvictions } from "./global-sync/session-cache"
+import { diffs as list, message as clean } from "@/utils/diffs"
 
 const SKIP_PARTS = new Set(["patch", "step-start", "step-finish"])
 
@@ -300,7 +301,7 @@ export const { use: useSync, provider: SyncProvider } = createSimpleContext({
         input.client.session.messages({ sessionID: input.sessionID, limit: input.limit, before: input.before }),
       )
       const items = (messages.data ?? []).filter((x) => !!x?.info?.id)
-      const session = items.map((x) => x.info).sort((a, b) => cmp(a.id, b.id))
+      const session = items.map((x) => clean(x.info)).sort((a, b) => cmp(a.id, b.id))
       const part = items.map((message) => ({ id: message.info.id, part: sortParts(message.parts) }))
       const cursor = messages.response.headers.get("x-next-cursor") ?? undefined
       return {
@@ -509,7 +510,7 @@ export const { use: useSync, provider: SyncProvider } = createSimpleContext({
           return runInflight(inflightDiff, key, () =>
             retry(() => client.session.diff({ sessionID })).then((diff) => {
               if (!tracked(directory, sessionID)) return
-              setStore("session_diff", sessionID, reconcile(diff.data ?? [], { key: "file" }))
+              setStore("session_diff", sessionID, reconcile(list(diff.data), { key: "file" }))
             }),
           )
         },
diff --git a/packages/app/src/pages/session.tsx b/packages/app/src/pages/session.tsx
index cf50fbe90..eb6a49411 100644
--- a/packages/app/src/pages/session.tsx
+++ b/packages/app/src/pages/session.tsx
@@ -58,6 +58,7 @@ import { TerminalPanel } from "@/pages/session/terminal-panel"
 import { useSessionCommands } from "@/pages/session/use-session-commands"
 import { useSessionHashScroll } from "@/pages/session/use-session-hash-scroll"
 import { Identifier } from "@/utils/id"
+import { diffs as list } from "@/utils/diffs"
 import { Persist, persisted } from "@/utils/persist"
 import { extractPromptFromParts } from "@/utils/prompt"
 import { same } from "@/utils/same"
@@ -430,7 +431,7 @@ export default function Page() {
 
   const info = createMemo(() => (params.id ? sync.session.get(params.id) : undefined))
   const isChildSession = createMemo(() => !!info()?.parentID)
-  const diffs = createMemo(() => (params.id ? (sync.data.session_diff[params.id] ?? []) : []))
+  const diffs = createMemo(() => (params.id ? list(sync.data.session_diff[params.id]) : []))
   const sessionCount = createMemo(() => Math.max(info()?.summary?.files ?? 0, diffs().length))
   const hasSessionReview = createMemo(() => sessionCount() > 0)
   const canReview = createMemo(() => !!sync.project)
@@ -611,7 +612,7 @@ export default function Page() {
       .diff({ mode })
       .then((result) => {
         if (vcsRun.get(mode) !== run) return
-        setVcs("diff", mode, result.data ?? [])
+        setVcs("diff", mode, list(result.data))
         setVcs("ready", mode, true)
       })
       .catch((error) => {
@@ -649,7 +650,7 @@ export default function Page() {
     return open
   }, desktopReviewOpen())
 
-  const turnDiffs = createMemo(() => lastUserMessage()?.summary?.diffs ?? [])
+  const turnDiffs = createMemo(() => list(lastUserMessage()?.summary?.diffs))
   const nogit = createMemo(() => !!sync.project && sync.project.vcs !== "git")
   const changesOptions = createMemo<ChangeMode[]>(() => {
     const list: ChangeMode[] = []
@@ -669,15 +670,11 @@ export default function Page() {
     if (store.changes === "git" || store.changes === "branch") return store.changes
   })
   const reviewDiffs = createMemo(() => {
-    if (store.changes === "git") return vcs.diff.git
-    if (store.changes === "branch") return vcs.diff.branch
+    if (store.changes === "git") return list(vcs.diff.git)
+    if (store.changes === "branch") return list(vcs.diff.branch)
     return turnDiffs()
   })
-  const reviewCount = createMemo(() => {
-    if (store.changes === "git") return vcs.diff.git.length
-    if (store.changes === "branch") return vcs.diff.branch.length
-    return turnDiffs().length
-  })
+  const reviewCount = createMemo(() => reviewDiffs().length)
   const hasReview = createMemo(() => reviewCount() > 0)
   const reviewReady = createMemo(() => {
     if (store.changes === "git") return vcs.ready.git
diff --git a/packages/app/src/utils/diffs.test.ts b/packages/app/src/utils/diffs.test.ts
new file mode 100644
index 000000000..5fbca469b
--- /dev/null
+++ b/packages/app/src/utils/diffs.test.ts
@@ -0,0 +1,74 @@
+import { describe, expect, test } from "bun:test"
+import type { SnapshotFileDiff } from "@opencode-ai/sdk/v2"
+import type { Message } from "@opencode-ai/sdk/v2/client"
+import { diffs, message } from "./diffs"
+
+const item = {
+  file: "src/app.ts",
+  patch: "@@ -1 +1 @@\n-old\n+new\n",
+  additions: 1,
+  deletions: 1,
+  status: "modified",
+} satisfies SnapshotFileDiff
+
+describe("diffs", () => {
+  test("keeps valid arrays", () => {
+    expect(diffs([item])).toEqual([item])
+  })
+
+  test("wraps a single diff object", () => {
+    expect(diffs(item)).toEqual([item])
+  })
+
+  test("reads keyed diff objects", () => {
+    expect(diffs({ a: item })).toEqual([item])
+  })
+
+  test("drops invalid entries", () => {
+    expect(
+      diffs([
+        item,
+        { file: "src/bad.ts", additions: 1, deletions: 1 },
+        { patch: item.patch, additions: 1, deletions: 1 },
+      ]),
+    ).toEqual([item])
+  })
+})
+
+describe("message", () => {
+  test("normalizes user summaries with object diffs", () => {
+    const input = {
+      id: "msg_1",
+      sessionID: "ses_1",
+      role: "user",
+      time: { created: 1 },
+      agent: "build",
+      model: { providerID: "openai", modelID: "gpt-5" },
+      summary: {
+        title: "Edit",
+        diffs: { a: item },
+      },
+    } as unknown as Message
+
+    expect(message(input)).toMatchObject({
+      summary: {
+        title: "Edit",
+        diffs: [item],
+      },
+    })
+  })
+
+  test("drops invalid user summaries", () => {
+    const input = {
+      id: "msg_1",
+      sessionID: "ses_1",
+      role: "user",
+      time: { created: 1 },
+      agent: "build",
+      model: { providerID: "openai", modelID: "gpt-5" },
+      summary: true,
+    } as unknown as Message
+
+    expect(message(input)).toMatchObject({ summary: undefined })
+  })
+})
diff --git a/packages/app/src/utils/diffs.ts b/packages/app/src/utils/diffs.ts
new file mode 100644
index 000000000..0cb2504fb
--- /dev/null
+++ b/packages/app/src/utils/diffs.ts
@@ -0,0 +1,49 @@
+import type { SnapshotFileDiff, VcsFileDiff } from "@opencode-ai/sdk/v2"
+import type { Message } from "@opencode-ai/sdk/v2/client"
+
+type Diff = SnapshotFileDiff | VcsFileDiff
+
+function diff(value: unknown): value is Diff {
+  if (!value || typeof value !== "object" || Array.isArray(value)) return false
+  if (!("file" in value) || typeof value.file !== "string") return false
+  if (!("patch" in value) || typeof value.patch !== "string") return false
+  if (!("additions" in value) || typeof value.additions !== "number") return false
+  if (!("deletions" in value) || typeof value.deletions !== "number") return false
+  if (!("status" in value) || value.status === undefined) return true
+  return value.status === "added" || value.status === "deleted" || value.status === "modified"
+}
+
+function object(value: unknown): value is Record<string, unknown> {
+  return !!value && typeof value === "object" && !Array.isArray(value)
+}
+
+export function diffs(value: unknown): Diff[] {
+  if (Array.isArray(value) && value.every(diff)) return value
+  if (Array.isArray(value)) return value.filter(diff)
+  if (diff(value)) return [value]
+  if (!object(value)) return []
+  return Object.values(value).filter(diff)
+}
+
+export function message(value: Message): Message {
+  if (value.role !== "user") return value
+
+  const raw = value.summary as unknown
+  if (raw === undefined) return value
+  if (!object(raw)) return { ...value, summary: undefined }
+
+  const title = typeof raw.title === "string" ? raw.title : undefined
+  const body = typeof raw.body === "string" ? raw.body : undefined
+  const next = diffs(raw.diffs)
+
+  if (title === raw.title && body === raw.body && next === raw.diffs) return value
+
+  return {
+    ...value,
+    summary: {
+      ...(title === undefined ? {} : { title }),
+      ...(body === undefined ? {} : { body }),
+      diffs: next,
+    },
+  }
+}