feat(app): better diff/code comments (#14621)

Co-authored-by: adamelmore <2363879+adamdottv@users.noreply.github.com>
Co-authored-by: David Hill <iamdavidhill@gmail.com>

packages/app/src/components/prompt-input/history.test.ts

@@ -3,25 +3,42 @@ import type { Prompt } from "@/context/prompt"
 import {
   canNavigateHistoryAtCursor,
   clonePromptParts,
+  normalizePromptHistoryEntry,
   navigatePromptHistory,
   prependHistoryEntry,
   promptLength,
+  type PromptHistoryComment,
 } from "./history"
 
 const DEFAULT_PROMPT: Prompt = [{ type: "text", content: "", start: 0, end: 0 }]
 
 const text = (value: string): Prompt => [{ type: "text", content: value, start: 0, end: value.length }]
+const comment = (id: string, value = "note"): PromptHistoryComment => ({
+  id,
+  path: "src/a.ts",
+  selection: { start: 2, end: 4 },
+  comment: value,
+  time: 1,
+  origin: "review",
+  preview: "const a = 1",
+})
 
 describe("prompt-input history", () => {
   test("prependHistoryEntry skips empty prompt and deduplicates consecutive entries", () => {
     const first = prependHistoryEntry([], DEFAULT_PROMPT)
     expect(first).toEqual([])
 
+    const commentsOnly = prependHistoryEntry([], DEFAULT_PROMPT, [comment("c1")])
+    expect(commentsOnly).toHaveLength(1)
+
     const withOne = prependHistoryEntry([], text("hello"))
     expect(withOne).toHaveLength(1)
 
     const deduped = prependHistoryEntry(withOne, text("hello"))
     expect(deduped).toBe(withOne)
+
+    const dedupedComments = prependHistoryEntry(commentsOnly, DEFAULT_PROMPT, [comment("c1")])
+    expect(dedupedComments).toBe(commentsOnly)
   })
 
   test("navigatePromptHistory restores saved prompt when moving down from newest", () => {
@@ -31,24 +48,57 @@ describe("prompt-input history", () => {
       entries,
       historyIndex: -1,
       currentPrompt: text("draft"),
+      currentComments: [comment("draft")],
       savedPrompt: null,
     })
     expect(up.handled).toBe(true)
     if (!up.handled) throw new Error("expected handled")
     expect(up.historyIndex).toBe(0)
     expect(up.cursor).toBe("start")
+    expect(up.entry.comments).toEqual([])
 
     const down = navigatePromptHistory({
       direction: "down",
       entries,
       historyIndex: up.historyIndex,
       currentPrompt: text("ignored"),
+      currentComments: [],
       savedPrompt: up.savedPrompt,
     })
     expect(down.handled).toBe(true)
     if (!down.handled) throw new Error("expected handled")
     expect(down.historyIndex).toBe(-1)
-    expect(down.prompt[0]?.type === "text" ? down.prompt[0].content : "").toBe("draft")
+    expect(down.entry.prompt[0]?.type === "text" ? down.entry.prompt[0].content : "").toBe("draft")
+    expect(down.entry.comments).toEqual([comment("draft")])
+  })
+
+  test("navigatePromptHistory keeps entry comments when moving through history", () => {
+    const entries = [
+      {
+        prompt: text("with comment"),
+        comments: [comment("c1")],
+      },
+    ]
+
+    const up = navigatePromptHistory({
+      direction: "up",
+      entries,
+      historyIndex: -1,
+      currentPrompt: text("draft"),
+      currentComments: [],
+      savedPrompt: null,
+    })
+
+    expect(up.handled).toBe(true)
+    if (!up.handled) throw new Error("expected handled")
+    expect(up.entry.prompt[0]?.type === "text" ? up.entry.prompt[0].content : "").toBe("with comment")
+    expect(up.entry.comments).toEqual([comment("c1")])
+  })
+
+  test("normalizePromptHistoryEntry supports legacy prompt arrays", () => {
+    const entry = normalizePromptHistoryEntry(text("legacy"))
+    expect(entry.prompt[0]?.type === "text" ? entry.prompt[0].content : "").toBe("legacy")
+    expect(entry.comments).toEqual([])
   })
 
   test("helpers clone prompt and count text content length", () => {