Show recent commit history in the explorer (#2312)

* feat(app): show recent commit history in explorer

* fix(app): keep recent commit history accurate

* fix(app): include merged commits in recent history

* perf(app): bound recent commit classification

* fix(app): refresh recent commits on Git updates

packages/server/src/utils/checkout-git.commits.test.ts

@@ -52,7 +52,7 @@ function addBareRemote(repoDir: string, tempDir: string): string {
 }
 
 describe("listCheckoutCommits", () => {
-  it("lists commits ahead of base newest-first with on-remote flags and file stats", async () => {
+  it("lists recent commits newest-first with on-remote flags and file stats", async () => {
     const { repoDir, tempDir } = initRepoOnMain();
     git(["checkout", "-b", "feature"], repoDir);
     commitFile(repoDir, "foo.txt", "a\nb\nc\n", "Add foo");
@@ -65,12 +65,14 @@ describe("listCheckoutCommits", () => {
     const { baseRef, commits } = await listCheckoutCommits({ cwd: repoDir });
 
     expect(baseRef).toBe("main");
-    expect(commits).toHaveLength(2);
+    expect(commits).toHaveLength(3);
     expect(commits[0]?.subject).toBe("Add bar");
     expect(commits[1]?.subject).toBe("Add foo");
+    expect(commits[2]?.subject).toBe("initial");
 
     expect(commits[0]?.isOnRemote).toBe(false);
     expect(commits[1]?.isOnRemote).toBe(true);
+    expect(commits[2]?.isOnRemote).toBe(true);
 
     expect(commits[0]?.files).toEqual([
       { path: "bar.txt", additions: 1, deletions: 0, status: "added" },
@@ -85,11 +87,11 @@ describe("listCheckoutCommits", () => {
     expect(Number.isNaN(new Date(commits[0]?.authorDate ?? "").getTime())).toBe(false);
   });
 
-  it("returns [] when there are no commits ahead of base", async () => {
+  it("shows recent history on the base branch", async () => {
     const { repoDir } = initRepoOnMain();
     const { baseRef, commits } = await listCheckoutCommits({ cwd: repoDir });
     expect(baseRef).toBeNull();
-    expect(commits).toEqual([]);
+    expect(commits.map((entry) => entry.subject)).toEqual(["initial"]);
   });
 
   it("marks all commits local-only when there is no remote", async () => {
@@ -101,10 +103,61 @@ describe("listCheckoutCommits", () => {
     const { baseRef, commits } = await listCheckoutCommits({ cwd: repoDir });
 
     expect(baseRef).toBe("main");
-    expect(commits).toHaveLength(2);
+    expect(commits).toHaveLength(3);
     expect(commits.every((c) => c.isOnRemote === false)).toBe(true);
   });
 
+  it("recognizes base history on a remote before the feature branch is pushed", async () => {
+    const { repoDir, tempDir } = initRepoOnMain();
+    addBareRemote(repoDir, tempDir);
+    git(["push", "-u", "origin", "main"], repoDir);
+    git(["checkout", "-b", "feature"], repoDir);
+    commitFile(repoDir, "feature.txt", "local\n", "Local feature");
+
+    const { commits } = await listCheckoutCommits({ cwd: repoDir });
+
+    expect(commits.map(({ subject, isOnRemote }) => ({ subject, isOnRemote }))).toEqual([
+      { subject: "Local feature", isOnRemote: false },
+      { subject: "initial", isOnRemote: true },
+    ]);
+  });
+
+  it("limits history and unpushed classification to the 20 most recent commits", async () => {
+    const { repoDir } = initRepoOnMain();
+    for (let index = 1; index <= 24; index += 1) {
+      commitFile(repoDir, "history.txt", `${index}\n`, `Commit ${index}`);
+    }
+
+    const { commits } = await listCheckoutCommits({ cwd: repoDir });
+
+    expect(commits).toHaveLength(20);
+    expect(commits.every((entry) => entry.isOnRemote === false)).toBe(true);
+    expect(commits.map((entry) => entry.subject)).toEqual(
+      Array.from({ length: 20 }, (_, index) => `Commit ${24 - index}`),
+    );
+  });
+
+  it("shows merged branch commits and compares the merge against its first parent", async () => {
+    const { repoDir } = initRepoOnMain();
+    git(["checkout", "-b", "feature"], repoDir);
+    commitFile(repoDir, "feature.txt", "feature\n", "Add feature");
+    git(["checkout", "main"], repoDir);
+    commitFile(repoDir, "main.txt", "main\n", "Advance main");
+    git(["merge", "--no-ff", "feature", "-m", "Merge feature"], repoDir);
+
+    const { commits } = await listCheckoutCommits({ cwd: repoDir });
+
+    expect(commits.map((entry) => entry.subject)).toEqual([
+      "Merge feature",
+      "Advance main",
+      "Add feature",
+      "initial",
+    ]);
+    expect(commits[0]?.files).toEqual([
+      { path: "feature.txt", additions: 1, deletions: 0, status: "added" },
+    ]);
+  });
+
   it("classifies renamed files with status renamed and correct destination path", async () => {
     const { repoDir } = initRepoOnMain();
     git(["checkout", "-b", "feature"], repoDir);