test: add MCP end-to-end coverage (#25)

Author: benvinegar

test/mcp-e2e.test.ts

@@ -0,0 +1,188 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
+
+const repoRoot = process.cwd();
+const sourceEntrypoint = join(repoRoot, "src/main.tsx");
+const tempDirs: string[] = [];
+const ttyToolsAvailable = Bun.spawnSync(["bash", "-lc", "command -v script >/dev/null && command -v timeout >/dev/null"], {
+  stdin: "ignore",
+  stdout: "ignore",
+  stderr: "ignore",
+}).exitCode === 0;
+
+function cleanupTempDirs() {
+  while (tempDirs.length > 0) {
+    const dir = tempDirs.pop();
+    if (dir) {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  }
+}
+
+function shellQuote(value: string) {
+  return `'${value.replaceAll("'", "'\\''")}'`;
+}
+
+function stripTerminalControl(text: string) {
+  return text
+    .replace(/^Script started.*?\n/s, "")
+    .replace(/\nScript done.*$/s, "")
+    .replace(/\x1bP[\s\S]*?\x1b\\/g, "")
+    .replace(/\x1b\][\s\S]*?(?:\x07|\x1b\\)/g, "")
+    .replace(/\x1b\[[0-?]*[ -/]*[@-~]/g, "")
+    .replace(/\x1b[@-_]/g, "");
+}
+
+function createFixtureFiles() {
+  const dir = mkdtempSync(join(tmpdir(), "hunk-mcp-e2e-"));
+  tempDirs.push(dir);
+
+  const before = join(dir, "before.ts");
+  const after = join(dir, "after.ts");
+  const transcript = join(dir, "transcript.txt");
+
+  writeFileSync(before, ["export const alpha = 1;", "export const keep = true;", ""].join("\n"));
+  writeFileSync(after, ["export const alpha = 2;", "export const keep = true;", "export const gamma = true;", ""].join("\n"));
+
+  return { dir, before, after, transcript };
+}
+
+async function waitUntil<T>(label: string, fn: () => Promise<T | null>, timeoutMs = 10_000, intervalMs = 150) {
+  const deadline = Date.now() + timeoutMs;
+
+  for (;;) {
+    const value = await fn();
+    if (value !== null) {
+      return value;
+    }
+
+    if (Date.now() >= deadline) {
+      throw new Error(`Timed out waiting for ${label}.`);
+    }
+
+    await Bun.sleep(intervalMs);
+  }
+}
+
+async function waitForHealth(port: number) {
+  return waitUntil("MCP daemon health endpoint", async () => {
+    try {
+      const response = await fetch(`http://127.0.0.1:${port}/health`);
+      if (!response.ok) {
+        return null;
+      }
+
+      return await response.json();
+    } catch {
+      return null;
+    }
+  });
+}
+
+afterEach(() => {
+  cleanupTempDirs();
+});
+
+describe("MCP end-to-end", () => {
+  test("daemon comment calls reach a live Hunk TTY session and render inline notes", async () => {
+    if (!ttyToolsAvailable) {
+      return;
+    }
+
+    const fixture = createFixtureFiles();
+    const port = 48000 + Math.floor(Math.random() * 1000);
+    const daemonProc = Bun.spawn(["bun", "run", sourceEntrypoint, "--", "mcp", "serve"], {
+      cwd: repoRoot,
+      stdin: "ignore",
+      stdout: "pipe",
+      stderr: "pipe",
+      env: {
+        ...process.env,
+        HUNK_MCP_PORT: String(port),
+      },
+    });
+
+    const hunkCommand = [
+      `(sleep 6; printf q) | timeout 8 script -q -f -e -c`,
+      shellQuote(`bun run ${shellQuote(sourceEntrypoint)} diff ${shellQuote(fixture.before)} ${shellQuote(fixture.after)}`),
+      shellQuote(fixture.transcript),
+    ].join(" ");
+    const hunkProc = Bun.spawn(["bash", "-lc", hunkCommand], {
+      cwd: fixture.dir,
+      stdin: "ignore",
+      stdout: "pipe",
+      stderr: "pipe",
+      env: {
+        ...process.env,
+        TERM: "xterm-256color",
+        COLUMNS: "120",
+        LINES: "24",
+        HUNK_MCP_PORT: String(port),
+      },
+    });
+
+    let client: Client | null = null;
+    let transport: StreamableHTTPClientTransport | null = null;
+
+    try {
+      await waitForHealth(port);
+
+      client = new Client({ name: "mcp-e2e-test", version: "1.0.0" });
+      transport = new StreamableHTTPClientTransport(new URL(`http://127.0.0.1:${port}/mcp`));
+      await client.connect(transport);
+
+      const listed = await waitUntil("registered Hunk session", async () => {
+        const result = await client!.callTool({
+          name: "list_sessions",
+          arguments: {},
+        });
+        const sessions = (result.structuredContent as { sessions?: Array<{ sessionId: string; title: string }> } | undefined)?.sessions;
+
+        if (!sessions || sessions.length === 0) {
+          return null;
+        }
+
+        return sessions;
+      });
+
+      const targetSession = listed.find((session) => session.title.includes("after.ts")) ?? listed[0]!;
+      const commentResult = await client.callTool({
+        name: "comment",
+        arguments: {
+          sessionId: targetSession.sessionId,
+          filePath: "after.ts",
+          side: "new",
+          line: 2,
+          summary: "MCP e2e note",
+          rationale: "Injected from the automated MCP integration test.",
+          author: "Pi",
+          reveal: true,
+        },
+      });
+
+      const structured = commentResult.structuredContent as { result?: { filePath?: string; line?: number } } | undefined;
+      expect(structured?.result?.filePath).toBe("after.ts");
+      expect(structured?.result?.line).toBe(2);
+
+      const hunkExitCode = await hunkProc.exited;
+      expect([0, 124]).toContain(hunkExitCode);
+
+      const transcript = stripTerminalControl(await Bun.file(fixture.transcript).text());
+      expect(transcript).toContain("MCP e2e note");
+      expect(transcript).toContain("Injected from the automated");
+    } finally {
+      if (transport) {
+        await transport.close().catch(() => undefined);
+      }
+
+      hunkProc.kill();
+      daemonProc.kill();
+      await hunkProc.exited.catch(() => undefined);
+      await daemonProc.exited.catch(() => undefined);
+    }
+  }, 20_000);
+});