feat(app): v2 review panel overhaul (#31882)

Co-authored-by: LukeParkerDev <10430890+Hona@users.noreply.github.com>

packages/app/e2e/performance/timeline/timeline-test-helpers.ts

@@ -21,7 +21,10 @@ export async function installTimelineSettings(page: Page) {
 
 export function mockStressTimeline(
   page: Page,
-  input?: { onMessages?: (input: { sessionID: string; before?: string; phase: "start" | "end" }) => void },
+  input?: {
+    onMessages?: (input: { sessionID: string; before?: string; phase: "start" | "end" }) => void
+    vcsDiff?: unknown[]
+  },
 ) {
   return mockOpenCodeServer(page, {
     sessions: fixture.sessions,
@@ -30,6 +33,7 @@ export function mockStressTimeline(
     project: fixture.project,
     pageMessages,
     onMessages: input?.onMessages,
+    vcsDiff: input?.vcsDiff,
   })
 }
 
@@ -78,3 +82,53 @@ export function stressDraftHref(draftID: string) {
 function stressServer() {
   return `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
 }
+
+export function createReviewDiffs() {
+  return Array.from({ length: Number(process.env.REVIEW_PANE_DIFF_COUNT ?? 72) }, (_, index) => {
+    const lines = index % 3 === 0 ? 300 : index % 3 === 1 ? 120 : 38
+    const file = `src/review/generated-${String(index).padStart(3, "0")}.ts`
+    const before = reviewSource(index, lines)
+    const after = before
+      .replace(`value_${index}_4`, `updated_${index}_4`)
+      .replace(
+        `value_${index}_${Math.max(8, Math.floor(lines / 2))}`,
+        `updated_${index}_${Math.max(8, Math.floor(lines / 2))}`,
+      )
+      .replace(`value_${index}_${lines - 4}`, `updated_${index}_${lines - 4}`)
+    return {
+      file,
+      patch: reviewPatch(file, before, after),
+      additions: 3,
+      deletions: 3,
+      status: "modified" as const,
+    }
+  })
+}
+
+function reviewSource(seed: number, lines: number) {
+  return Array.from(
+    { length: lines },
+    (_, index) => `export const value_${seed}_${index} = "${reviewWords(seed + index, index % 5 === 0 ? 180 : 42)}"`,
+  ).join("\n")
+}
+
+function reviewPatch(file: string, before: string, after: string) {
+  const beforeLines = before.split("\n")
+  const afterLines = after.split("\n")
+  return [
+    `diff --git a/${file} b/${file}`,
+    `--- a/${file}`,
+    `+++ b/${file}`,
+    `@@ -1,${beforeLines.length} +1,${afterLines.length} @@`,
+    ...beforeLines.flatMap((line, index) => {
+      const next = afterLines[index]!
+      if (line === next) return [` ${line}`]
+      return [`-${line}`, `+${next}`]
+    }),
+  ].join("\n")
+}
+
+function reviewWords(seed: number, length: number) {
+  const words = ["alpha", "bravo", "charlie", "delta", "echo", "foxtrot", "golf", "hotel", "india", "juliet"]
+  return Array.from({ length: Math.ceil(length / 7) }, (_, index) => words[(seed + index * 3) % words.length]).join(" ")
+}