Use the merge queue for pull requests that require it

docs/buzz-help.md

@@ -330,6 +330,9 @@ available rather than silently discarding it.
   macOS (inside the app's installed name, such as `Buzz Foundation.app`), with
   no setup or token. Without such a plugin there are no tools to
   offer; do not promise them.
+- The **GitHub** plugin’s pull request panel offers **Queue for merge** when
+  the target branch requires a merge queue. After confirmation, it queues the
+  displayed commit and shows **Queued for merge**; GitHub controls when it merges.
 - Some desktop plugins can upload images you provide to services they declare.
 - **Attention**, when available, lets agents use Interests, watches, and timers
   to follow work. Its tab in an agent's profile shows what that agent is watching

src/bundled/github/GitHubPanel.test.tsx

@@ -594,62 +594,142 @@ it("merges after confirming, at the head it showed, then shows it merged", async
   ).not.toBeInTheDocument();
 });
 
-it("closes the merge confirmation when a refresh brings a newer push", async () => {
-  vi.useFakeTimers({ shouldAdvanceTime: true });
-  try {
-    const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
-    let head = "abc123";
-    const gh = vi.fn(async (query: string, _variables?: unknown) =>
-      query.startsWith("mutation")
-        ? {}
-        : pullData({
-            headRefOid: head,
-            ...(head !== "abc123" && { title: "Pushed again" }),
-          }),
-    );
+it.each(["CLEAN", "BLOCKED", "BEHIND"])(
+  "queues the displayed head on a queue-required branch (%s), then shows it queued",
+  async (mergeStateStatus) => {
+    const user = userEvent.setup();
+    let queued = false;
+    const gh = vi.fn(async (query: string, _variables?: unknown) => {
+      if (query.startsWith("mutation")) {
+        queued = true;
+        return {};
+      }
+      return pullData({
+        isMergeQueueEnabled: true,
+        isInMergeQueue: queued,
+        mergeStateStatus,
+        viewerCanMergeAsAdmin: true,
+        viewerCanEnableAutoMerge: true,
+      });
+    });
     render(
       <GitHubPanel
         target={pull}
         close={() => {}}
         gh={gh as unknown as GitHubCli}
       />,
     );
-    await screen.findByRole("heading", { name: "Private change #9" });
-    await user.click(screen.getByRole("button", { name: "Squash and merge" }));
+    const button = await screen.findByRole("button", {
+      name: "Queue for merge",
+    });
+    expect(button).toHaveAttribute("data-variant", "prominent");
+    expect(
+      screen.queryByRole("button", { name: "Squash and merge" }),
+    ).not.toBeInTheDocument();
+    await user.click(
+      screen.getByRole("button", { name: "More pull request actions" }),
+    );
+    expect(
+      (await screen.findAllByRole("menuitem")).map((item) => item.textContent),
+    ).toEqual(["Convert to draft"]);
+    await user.keyboard("{Escape}");
+    await user.click(button);
     const dialog = await screen.findByRole("alertdialog");
-    head = "def456";
-    await vi.advanceTimersByTimeAsync(REFRESH_MS);
-    await screen.findByRole("heading", { name: "Pushed again #9" });
-    expect(dialog).not.toBeInTheDocument();
-    // Confirming again names the head now shown.
-    await user.click(screen.getByRole("button", { name: "Squash and merge" }));
+    expect(dialog).toHaveAccessibleName("Queue for merge #9?");
+    expect(gh).toHaveBeenCalledTimes(1);
     await user.click(
-      within(await screen.findByRole("alertdialog")).getByRole("button", {
-        name: "Merge",
+      within(dialog).getByRole("button", { name: "Queue for merge" }),
+    );
+    await screen.findByText("Queued for merge");
+    expect(row("Merge")).toHaveTextContent("Queued for merge into main");
+    expect(gh.mock.calls[0]?.[0]).toContain(
+      "isMergeQueueEnabled isInMergeQueue",
+    );
+    expect(gh.mock.calls[1]).toEqual([
+      "mutation($input:EnqueuePullRequestInput!){enqueuePullRequest(input:$input){clientMutationId}}",
+      { input: { pullRequestId: "PR_9", expectedHeadOid: "abc123" } },
+      undefined,
+    ]);
+    expect(screen.queryByRole("alertdialog")).not.toBeInTheDocument();
+    expect(
+      screen.queryByRole("button", { name: "Queue for merge" }),
+    ).not.toBeInTheDocument();
+    expect(
+      screen.queryByRole("button", { name: "Merge when ready" }),
+    ).not.toBeInTheDocument();
+  },
+);
+
+it.each([
+  { mergeStateStatus: "DIRTY" },
+  { mergeStateStatus: "UNKNOWN" },
+  { isDraft: true },
+  { isInMergeQueue: true },
+])(
+  "does not offer queueing an ineligible or already queued pull (%j)",
+  async (over) => {
+    const gh = vi.fn(async () =>
+      pullData({
+        isMergeQueueEnabled: true,
+        viewerCanEnableAutoMerge: true,
+        ...over,
       }),
     );
-    await vi.waitFor(() => expect(gh).toHaveBeenCalledTimes(4));
-    expect(gh.mock.calls[2]?.[1]).toEqual({
-      input: {
-        pullRequestId: "PR_9",
-        expectedHeadOid: "def456",
-        mergeMethod: "SQUASH",
-      },
-    });
-  } finally {
-    vi.useRealTimers();
-  }
+    render(
+      <GitHubPanel
+        target={pull}
+        close={() => {}}
+        gh={gh as unknown as GitHubCli}
+      />,
+    );
+    await screen.findByRole("heading", { name: "Private change #9" });
+    expect(
+      screen.queryByRole("button", { name: "Queue for merge" }),
+    ).not.toBeInTheDocument();
+    expect(
+      screen.queryByRole("button", { name: "Merge when ready" }),
+    ).not.toBeInTheDocument();
+  },
+);
+
+it("shows GitHub's queue rejection and allows retrying the confirmed head", async () => {
+  const user = userEvent.setup();
+  const gh = vi.fn(async (query: string) => {
+    if (query.startsWith("mutation"))
+      throw new GitHubError("Required approvals are missing");
+    return pullData({ isMergeQueueEnabled: true, mergeStateStatus: "BLOCKED" });
+  });
+  render(
+    <GitHubPanel
+      target={pull}
+      close={() => {}}
+      gh={gh as unknown as GitHubCli}
+    />,
+  );
+  await user.click(
+    await screen.findByRole("button", { name: "Queue for merge" }),
+  );
+  const dialog = await screen.findByRole("alertdialog");
+  await user.click(
+    within(dialog).getByRole("button", { name: "Queue for merge" }),
+  );
+  expect(await within(dialog).findByRole("alert")).toHaveTextContent(
+    "Required approvals are missing",
+  );
+  expect(
+    within(dialog).getByRole("button", { name: "Queue for merge" }),
+  ).toBeEnabled();
 });
 
-it("closes the merge confirmation when the pull request is retargeted, for good", async () => {
+it("closes a merge confirmation if the branch starts requiring a queue", async () => {
   vi.useFakeTimers({ shouldAdvanceTime: true });
   try {
     const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
-    let base = "main";
+    let queue = false;
     const gh = vi.fn(async () =>
       pullData({
-        baseRefName: base,
-        ...(base !== "main" && { title: "Retargeted" }),
+        isMergeQueueEnabled: queue,
+        ...(queue && { title: "Queue required" }),
       }),
     );
     render(
@@ -659,23 +739,124 @@ it("closes the merge confirmation when the pull request is retargeted, for good"
         gh={gh as unknown as GitHubCli}
       />,
     );
-    await screen.findByRole("heading", { name: "Private change #9" });
-    await user.click(screen.getByRole("button", { name: "Squash and merge" }));
+    await user.click(
+      await screen.findByRole("button", { name: "Squash and merge" }),
+    );
     const dialog = await screen.findByRole("alertdialog");
-    base = "release";
+    queue = true;
     await vi.advanceTimersByTimeAsync(REFRESH_MS);
-    await screen.findByRole("heading", { name: "Retargeted #9" });
+    await screen.findByRole("heading", { name: "Queue required #9" });
     expect(dialog).not.toBeInTheDocument();
-    // Changing back does not open it again without another click.
-    base = "main";
-    await vi.advanceTimersByTimeAsync(REFRESH_MS);
-    await screen.findByRole("heading", { name: "Private change #9" });
-    expect(screen.queryByRole("alertdialog")).not.toBeInTheDocument();
+    expect(
+      screen.getByRole("button", { name: "Queue for merge" }),
+    ).toBeInTheDocument();
   } finally {
     vi.useRealTimers();
   }
 });
 
+it.each([false, true])(
+  "closes the merge confirmation when a refresh brings a newer push (queue=%s)",
+  async (queue) => {
+    vi.useFakeTimers({ shouldAdvanceTime: true });
+    try {
+      const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+      let head = "abc123";
+      const gh = vi.fn(async (query: string, _variables?: unknown) =>
+        query.startsWith("mutation")
+          ? {}
+          : pullData({
+              isMergeQueueEnabled: queue,
+              headRefOid: head,
+              ...(head !== "abc123" && { title: "Pushed again" }),
+            }),
+      );
+      render(
+        <GitHubPanel
+          target={pull}
+          close={() => {}}
+          gh={gh as unknown as GitHubCli}
+        />,
+      );
+      await screen.findByRole("heading", { name: "Private change #9" });
+      await user.click(
+        screen.getByRole("button", {
+          name: queue ? "Queue for merge" : "Squash and merge",
+        }),
+      );
+      const dialog = await screen.findByRole("alertdialog");
+      head = "def456";
+      await vi.advanceTimersByTimeAsync(REFRESH_MS);
+      await screen.findByRole("heading", { name: "Pushed again #9" });
+      expect(dialog).not.toBeInTheDocument();
+      // Confirming again names the head now shown.
+      await user.click(
+        screen.getByRole("button", {
+          name: queue ? "Queue for merge" : "Squash and merge",
+        }),
+      );
+      await user.click(
+        within(await screen.findByRole("alertdialog")).getByRole("button", {
+          name: queue ? "Queue for merge" : "Merge",
+        }),
+      );
+      await vi.waitFor(() => expect(gh).toHaveBeenCalledTimes(4));
+      expect(gh.mock.calls[2]?.[1]).toEqual({
+        input: {
+          pullRequestId: "PR_9",
+          expectedHeadOid: "def456",
+          ...(!queue && { mergeMethod: "SQUASH" }),
+        },
+      });
+    } finally {
+      vi.useRealTimers();
+    }
+  },
+);
+
+it.each([false, true])(
+  "closes the merge confirmation when the pull request is retargeted, for good (queue=%s)",
+  async (queue) => {
+    vi.useFakeTimers({ shouldAdvanceTime: true });
+    try {
+      const user = userEvent.setup({ advanceTimers: vi.advanceTimersByTime });
+      let base = "main";
+      const gh = vi.fn(async () =>
+        pullData({
+          isMergeQueueEnabled: queue,
+          baseRefName: base,
+          ...(base !== "main" && { title: "Retargeted" }),
+        }),
+      );
+      render(
+        <GitHubPanel
+          target={pull}
+          close={() => {}}
+          gh={gh as unknown as GitHubCli}
+        />,
+      );
+      await screen.findByRole("heading", { name: "Private change #9" });
+      await user.click(
+        screen.getByRole("button", {
+          name: queue ? "Queue for merge" : "Squash and merge",
+        }),
+      );
+      const dialog = await screen.findByRole("alertdialog");
+      base = "release";
+      await vi.advanceTimersByTimeAsync(REFRESH_MS);
+      await screen.findByRole("heading", { name: "Retargeted #9" });
+      expect(dialog).not.toBeInTheDocument();
+      // Changing back does not open it again without another click.
+      base = "main";
+      await vi.advanceTimersByTimeAsync(REFRESH_MS);
+      await screen.findByRole("heading", { name: "Private change #9" });
+      expect(screen.queryByRole("alertdialog")).not.toBeInTheDocument();
+    } finally {
+      vi.useRealTimers();
+    }
+  },
+);
+
 it("says when threads beyond the latest 100 went unread, and gates actions on GitHub's viewer flags", async () => {
   const gh = vi.fn(async () =>
     pullData({