test: simplify tailscale helper coverage

src/infra/tailscale.test.ts

@@ -22,6 +22,13 @@ function createRuntimeWithExitError() {
   };
 }
 
+function expectServeFallbackCommand(params: { callArgs: string[]; sudoArgs: string[] }) {
+  return [
+    [tailscaleBin, expect.arrayContaining(params.callArgs)],
+    ["sudo", expect.arrayContaining(["-n", tailscaleBin, ...params.sudoArgs])],
+  ];
+}
+
 describe("tailscale helpers", () => {
   let envSnapshot: ReturnType<typeof captureEnv>;
 
@@ -53,53 +60,62 @@ describe("tailscale helpers", () => {
     expect(host).toBe("100.2.2.2");
   });
 
-  it("ensureGoInstalled installs when missing and user agrees", async () => {
-    const exec = vi.fn().mockRejectedValueOnce(new Error("no go")).mockResolvedValue({}); // brew install go
-    const prompt = vi.fn().mockResolvedValue(true);
-    const runtime = createRuntimeWithExitError();
-    await ensureGoInstalled(exec as never, prompt, runtime);
-    expect(exec).toHaveBeenCalledWith("brew", ["install", "go"]);
+  it("parses noisy JSON output from tailscale status", async () => {
+    const exec = vi.fn().mockResolvedValue({
+      stdout:
+        'warning: stale state\n{"Self":{"DNSName":"noisy.tailnet.ts.net.","TailscaleIPs":["100.9.9.9"]}}\n',
+    });
+    const host = await getTailnetHostname(exec);
+    expect(host).toBe("noisy.tailnet.ts.net");
   });
 
-  it("ensureGoInstalled exits when missing and user declines install", async () => {
-    const exec = vi.fn().mockRejectedValueOnce(new Error("no go"));
+  it.each([
+    {
+      name: "ensureGoInstalled installs when missing and user agrees",
+      fn: ensureGoInstalled,
+      missingError: new Error("no go"),
+      installCommand: ["brew", ["install", "go"]] as const,
+      promptResult: true,
+    },
+    {
+      name: "ensureTailscaledInstalled installs when missing and user agrees",
+      fn: ensureTailscaledInstalled,
+      missingError: new Error("missing"),
+      installCommand: ["brew", ["install", "tailscale"]] as const,
+      promptResult: true,
+    },
+  ])("$name", async ({ fn, missingError, installCommand, promptResult }) => {
+    const exec = vi.fn().mockRejectedValueOnce(missingError).mockResolvedValue({});
+    const prompt = vi.fn().mockResolvedValue(promptResult);
+    const runtime = createRuntimeWithExitError();
+    await fn(exec as never, prompt, runtime);
+    expect(exec).toHaveBeenCalledWith(installCommand[0], installCommand[1]);
+  });
+
+  it.each([
+    {
+      name: "ensureGoInstalled exits when missing and user declines install",
+      fn: ensureGoInstalled,
+      missingError: new Error("no go"),
+      errorMessage: "Go is required to build tailscaled from source. Aborting.",
+    },
+    {
+      name: "ensureTailscaledInstalled exits when missing and user declines install",
+      fn: ensureTailscaledInstalled,
+      missingError: new Error("missing"),
+      errorMessage: "tailscaled is required for user-space funnel. Aborting.",
+    },
+  ])("$name", async ({ fn, missingError, errorMessage }) => {
+    const exec = vi.fn().mockRejectedValueOnce(missingError);
     const prompt = vi.fn().mockResolvedValue(false);
     const runtime = createRuntimeWithExitError();
 
-    await expect(ensureGoInstalled(exec as never, prompt, runtime)).rejects.toThrow("exit 1");
-
-    expect(runtime.error).toHaveBeenCalledWith(
-      "Go is required to build tailscaled from source. Aborting.",
-    );
-    expect(exec).toHaveBeenCalledTimes(1);
-  });
-
-  it("ensureTailscaledInstalled installs when missing and user agrees", async () => {
-    const exec = vi.fn().mockRejectedValueOnce(new Error("missing")).mockResolvedValue({});
-    const prompt = vi.fn().mockResolvedValue(true);
-    const runtime = createRuntimeWithExitError();
-    await ensureTailscaledInstalled(exec as never, prompt, runtime);
-    expect(exec).toHaveBeenCalledWith("brew", ["install", "tailscale"]);
-  });
-
-  it("ensureTailscaledInstalled exits when missing and user declines install", async () => {
-    const exec = vi.fn().mockRejectedValueOnce(new Error("missing"));
-    const prompt = vi.fn().mockResolvedValue(false);
-    const runtime = createRuntimeWithExitError();
-
-    await expect(ensureTailscaledInstalled(exec as never, prompt, runtime)).rejects.toThrow(
-      "exit 1",
-    );
-
-    expect(runtime.error).toHaveBeenCalledWith(
-      "tailscaled is required for user-space funnel. Aborting.",
-    );
+    await expect(fn(exec as never, prompt, runtime)).rejects.toThrow("exit 1");
+    expect(runtime.error).toHaveBeenCalledWith(errorMessage);
     expect(exec).toHaveBeenCalledTimes(1);
   });
 
   it("enableTailscaleServe attempts normal first, then sudo", async () => {
-    // 1. First attempt fails
-    // 2. Second attempt (sudo) succeeds
     const exec = vi
       .fn()
       .mockRejectedValueOnce(new Error("permission denied"))
@@ -107,19 +123,12 @@ describe("tailscale helpers", () => {
 
     await enableTailscaleServe(3000, exec as never);
 
-    expect(exec).toHaveBeenNthCalledWith(
-      1,
-      tailscaleBin,
-      expect.arrayContaining(["serve", "--bg", "--yes", "3000"]),
-      expect.any(Object),
-    );
-
-    expect(exec).toHaveBeenNthCalledWith(
-      2,
-      "sudo",
-      expect.arrayContaining(["-n", tailscaleBin, "serve", "--bg", "--yes", "3000"]),
-      expect.any(Object),
-    );
+    const [firstCall, secondCall] = expectServeFallbackCommand({
+      callArgs: ["serve", "--bg", "--yes", "3000"],
+      sudoArgs: ["serve", "--bg", "--yes", "3000"],
+    });
+    expect(exec).toHaveBeenNthCalledWith(1, firstCall[0], firstCall[1], expect.any(Object));
+    expect(exec).toHaveBeenNthCalledWith(2, secondCall[0], secondCall[1], expect.any(Object));
   });
 
   it("enableTailscaleServe does NOT use sudo if first attempt succeeds", async () => {
@@ -153,10 +162,6 @@ describe("tailscale helpers", () => {
   });
 
   it("ensureFunnel uses fallback for enabling", async () => {
-    // Mock exec:
-    // 1. status (success)
-    // 2. enable (fails)
-    // 3. enable sudo (success)
     const exec = vi
       .fn()
       .mockResolvedValueOnce({ stdout: JSON.stringify({ BackendState: "Running" }) }) // status
@@ -172,22 +177,17 @@ describe("tailscale helpers", () => {
 
     await ensureFunnel(8080, exec as never, runtime, prompt);
 
-    // 1. status
     expect(exec).toHaveBeenNthCalledWith(
       1,
       tailscaleBin,
       expect.arrayContaining(["funnel", "status", "--json"]),
     );
-
-    // 2. enable normal
     expect(exec).toHaveBeenNthCalledWith(
       2,
       tailscaleBin,
       expect.arrayContaining(["funnel", "--yes", "--bg", "8080"]),
       expect.any(Object),
     );
-
-    // 3. enable sudo
     expect(exec).toHaveBeenNthCalledWith(
       3,
       "sudo",