Native surfaces migration — evolve the extension onto VS Code's native review surfaces (9-task plan, spec v0.2.1) (#72)

test/trackChangesModel.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, test, expect } from "vitest";
 import MarkdownIt from "markdown-it";
-import { splitBlocks, splitBlocksWithRanges, diffBlocks, diffToHunks, diffToBlockHunks, renderTrackChanges, colorByAuthor, authorAt, wordDiffByAuthor, type AuthorSpan } from "../src/trackChangesModel";
+import { splitBlocks, splitBlocksWithRanges, diffBlocks, diffToHunks, diffToBlockHunks, renderTrackChanges, colorByAuthor, authorAt, wordDiffByAuthor, countLineHunks, type AuthorSpan } from "../src/trackChangesModel";
 const md = new MarkdownIt({ html: true, linkify: false, breaks: false });
 
 describe("splitBlocks", () => {
@@ -440,9 +440,9 @@ describe("renderReview", () => {
     expect(html).toContain('data-proposal-id="p1"'); // proposal still shows (it is an action)
     expect(html).toContain("Person");
   });
-  test("renderReview: zero diff (e.g. machine-landing accept) renders unchanged blocks plain (Task 2 behavior)", () => {
+  test("renderReview: zero diff (baseline == current) renders unchanged blocks plain (Task 2 behavior)", () => {
     // Task 2: unchanged blocks always render plain — color means "changed since baseline".
-    // After accepting a Claude edit the text is the new baseline; no diff → no coloring.
+    // When baseline == current (e.g. right after a fresh snapshot) there's no diff → no coloring.
     const doc = "Human wrote this.\n\nClaude wrote that.";
     const spans: AuthorSpan[] = [{ start: 19, end: doc.length, author: "claude" }];
     const html = renderReview(doc, doc, spans, []); // no pinned flag
@@ -825,3 +825,19 @@ describe("F11 data-src emission (INV-36)", () => {
     expect(renderReview(doc, doc, [], [])).not.toContain('href="https://example.com/spec"');
   });
 });
+
+describe("countLineHunks", () => {
+  it("0 for identical text", () => {
+    expect(countLineHunks("a\nb\n", "a\nb\n")).toBe(0);
+  });
+  it("1 for one contiguous change", () => {
+    expect(countLineHunks("a\nb\nc\n", "a\nX\nc\n")).toBe(1);
+  });
+  it("2 for two separated changes", () => {
+    expect(countLineHunks("a\nb\nc\nd\ne\n", "a\nX\nc\nd\nY\n")).toBe(2);
+  });
+  it("counts pure insertions and deletions", () => {
+    expect(countLineHunks("a\n", "a\nb\n")).toBe(1);
+    expect(countLineHunks("a\nb\n", "a\n")).toBe(1);
+  });
+});