1 files changed, 163 insertions, 138 deletions

diff --git a/packages/mcp/src/transport.test.ts b/packages/mcp/src/transport.test.ts
index b369e74..8c69ad2 100644
--- a/packages/mcp/src/transport.test.ts
+++ b/packages/mcp/src/transport.test.ts
@@ -9,146 +9,171 @@ import { createStdioTransport } from "./transport.js";
  * what we wrote to the child's stdin (our outgoing framed messages).
  */
 function makePipe(): {
-	process: SpawnedProcess;
-	emitStdout: (data: Uint8Array) => void;
-	emitEnd: () => void;
-	writtenToStdin: () => Uint8Array[];
-	killed: () => boolean;
+  process: SpawnedProcess;
+  emitStdout: (data: Uint8Array) => void;
+  emitEnd: () => void;
+  writtenToStdin: () => Uint8Array[];
+  killed: () => boolean;
 } {
-	const dataListeners: Array<(data: Uint8Array) => void> = [];
-	const endListeners: Array<() => void> = [];
-	const stdinWrites: Uint8Array[] = [];
-	let killed = false;
-
-	const process: SpawnedProcess = {
-		stdin: {
-			write: (bytes: Uint8Array) => {
-				stdinWrites.push(bytes);
-			},
-		},
-		stdout: {
-			on: (event: string, cb: (data: Uint8Array) => void) => {
-				if (event === "data") dataListeners.push(cb);
-				else if (event === "end") endListeners.push(cb as unknown as () => void);
-			},
-		},
-		pid: 12345,
-		kill: () => {
-			killed = true;
-		},
-	};
-
-	return {
-		process,
-		emitStdout: (data: Uint8Array) => {
-			for (const cb of dataListeners) cb(data);
-		},
-		emitEnd: () => {
-			for (const cb of endListeners) cb();
-		},
-		writtenToStdin: () => stdinWrites,
-		killed: () => killed,
-	};
+  const dataListeners: Array<(data: Uint8Array) => void> = [];
+  const endListeners: Array<() => void> = [];
+  const stdinWrites: Uint8Array[] = [];
+  let killed = false;
+
+  const process: SpawnedProcess = {
+    stdin: {
+      write: (bytes: Uint8Array) => {
+        stdinWrites.push(bytes);
+      },
+    },
+    stdout: {
+      on: (event: string, cb: (data: Uint8Array) => void) => {
+        if (event === "data") dataListeners.push(cb);
+        else if (event === "end") endListeners.push(cb as unknown as () => void);
+      },
+    },
+    pid: 12345,
+    kill: () => {
+      killed = true;
+    },
+  };
+
+  return {
+    process,
+    emitStdout: (data: Uint8Array) => {
+      for (const cb of dataListeners) cb(data);
+    },
+    emitEnd: () => {
+      for (const cb of endListeners) cb();
+    },
+    writtenToStdin: () => stdinWrites,
+    killed: () => killed,
+  };
 }
 
 describe("createStdioTransport", () => {
-	it("creates connection with correct pid", () => {
-		const pair = makePipe();
-		const spawn: SpawnProcess = () => pair.process;
-
-		const { connection } = createStdioTransport({ spawn, command: ["test-server"] }, "/tmp");
-
-		expect(connection.pid).toBe(12345);
-		connection.close();
-	});
-
-	it("connection sends framed messages via stdin", () => {
-		const pair = makePipe();
-		const spawn: SpawnProcess = () => pair.process;
-
-		const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
-
-		connection.notify("test/method", { key: "value" });
-
-		const writes = pair.writtenToStdin();
-		expect(writes.length).toBe(1);
-		const text = new TextDecoder().decode(writes[0]);
-		expect(text).toContain("Content-Length:");
-		expect(text).toContain('"method":"test/method"');
-		connection.close();
-	});
-
-	it("close kills the child process", () => {
-		const pair = makePipe();
-		const spawn: SpawnProcess = () => pair.process;
-
-		const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
-
-		connection.close();
-		expect(pair.killed()).toBe(true);
-	});
-
-	it("pipes stdout through framing: a notification triggers onNotification", async () => {
-		const pair = makePipe();
-		const spawn: SpawnProcess = () => pair.process;
-
-		const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
-
-		let received: unknown = null;
-		connection.onNotification("notifications/tools/list_changed", (params) => {
-			received = params;
-		});
-
-		// Simulate the server writing a framed notification to stdout.
-		const notification = JSON.stringify({
-			jsonrpc: "2.0",
-			method: "notifications/tools/list_changed",
-			params: { reason: "tools added" },
-		});
-		pair.emitStdout(encode(notification));
-
-		// onNotification is invoked synchronously inside the data handler.
-		expect(received).toEqual({ reason: "tools added" });
-		connection.close();
-	});
-
-	it("pipes stdout through framing: a response resolves a request", async () => {
-		const pair = makePipe();
-		const spawn: SpawnProcess = () => pair.process;
-
-		const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
-
-		const resultPromise = connection.send("tools/list");
-
-		// The request was framed and written to stdin; respond via stdout.
-		const response = JSON.stringify({
-			jsonrpc: "2.0",
-			id: 1,
-			result: { tools: [{ name: "t", description: "d", inputSchema: { type: "object" } }] },
-		});
-		pair.emitStdout(encode(response));
-
-		const result = await resultPromise;
-		expect(result).toEqual({
-			tools: [{ name: "t", description: "d", inputSchema: { type: "object" } }],
-		});
-		connection.close();
-	});
-
-	it("handles a frame split across two stdout chunks", async () => {
-		const pair = makePipe();
-		const spawn: SpawnProcess = () => pair.process;
-
-		const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
-
-		const resultPromise = connection.send("ping");
-
-		const response = encode(JSON.stringify({ jsonrpc: "2.0", id: 1, result: { ok: true } }));
-		const mid = Math.floor(response.length / 2);
-		pair.emitStdout(response.slice(0, mid));
-		pair.emitStdout(response.slice(mid));
-
-		await expect(resultPromise).resolves.toEqual({ ok: true });
-		connection.close();
-	});
+  it("creates connection with correct pid", () => {
+    const pair = makePipe();
+    const spawn: SpawnProcess = () => pair.process;
+
+    const { connection } = createStdioTransport({ spawn, command: ["test-server"] }, "/tmp");
+
+    expect(connection.pid).toBe(12345);
+    connection.close();
+  });
+
+  it("connection sends newline-delimited messages via stdin (current MCP spec)", () => {
+    const pair = makePipe();
+    const spawn: SpawnProcess = () => pair.process;
+
+    const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
+
+    connection.notify("test/method", { key: "value" });
+
+    const writes = pair.writtenToStdin();
+    expect(writes.length).toBe(1);
+    const text = new TextDecoder().decode(writes[0]);
+    // Outgoing framing is newline-delimited JSON (not Content-Length).
+    expect(text).not.toContain("Content-Length:");
+    expect(text).toContain('"method":"test/method"');
+    expect(text.endsWith("\n")).toBe(true);
+    connection.close();
+  });
+
+  it("decodes a newline-delimited server response (auto-detect)", async () => {
+    const pair = makePipe();
+    const spawn: SpawnProcess = () => pair.process;
+
+    const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
+
+    const resultPromise = connection.send("tools/list");
+
+    // Server responds with newline-delimited JSON (e.g. chrome-devtools-mcp).
+    const response = `${JSON.stringify({
+      jsonrpc: "2.0",
+      id: 1,
+      result: { tools: [{ name: "t", description: "d", inputSchema: { type: "object" } }] },
+    })}\n`;
+    pair.emitStdout(new TextEncoder().encode(response));
+
+    const result = await resultPromise;
+    expect(result).toEqual({
+      tools: [{ name: "t", description: "d", inputSchema: { type: "object" } }],
+    });
+    connection.close();
+  });
+
+  it("close kills the child process", () => {
+    const pair = makePipe();
+    const spawn: SpawnProcess = () => pair.process;
+
+    const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
+
+    connection.close();
+    expect(pair.killed()).toBe(true);
+  });
+
+  it("pipes stdout through framing: a notification triggers onNotification", async () => {
+    const pair = makePipe();
+    const spawn: SpawnProcess = () => pair.process;
+
+    const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
+
+    let received: unknown = null;
+    connection.onNotification("notifications/tools/list_changed", (params) => {
+      received = params;
+    });
+
+    // Simulate the server writing a framed notification to stdout.
+    const notification = JSON.stringify({
+      jsonrpc: "2.0",
+      method: "notifications/tools/list_changed",
+      params: { reason: "tools added" },
+    });
+    pair.emitStdout(encode(notification));
+
+    // onNotification is invoked synchronously inside the data handler.
+    expect(received).toEqual({ reason: "tools added" });
+    connection.close();
+  });
+
+  it("pipes stdout through framing: a response resolves a request", async () => {
+    const pair = makePipe();
+    const spawn: SpawnProcess = () => pair.process;
+
+    const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
+
+    const resultPromise = connection.send("tools/list");
+
+    // The request was framed and written to stdin; respond via stdout.
+    const response = JSON.stringify({
+      jsonrpc: "2.0",
+      id: 1,
+      result: { tools: [{ name: "t", description: "d", inputSchema: { type: "object" } }] },
+    });
+    pair.emitStdout(encode(response));
+
+    const result = await resultPromise;
+    expect(result).toEqual({
+      tools: [{ name: "t", description: "d", inputSchema: { type: "object" } }],
+    });
+    connection.close();
+  });
+
+  it("handles a frame split across two stdout chunks", async () => {
+    const pair = makePipe();
+    const spawn: SpawnProcess = () => pair.process;
+
+    const { connection } = createStdioTransport({ spawn, command: ["test"] }, "/tmp");
+
+    const resultPromise = connection.send("ping");
+
+    const response = encode(JSON.stringify({ jsonrpc: "2.0", id: 1, result: { ok: true } }));
+    const mid = Math.floor(response.length / 2);
+    pair.emitStdout(response.slice(0, mid));
+    pair.emitStdout(response.slice(mid));
+
+    await expect(resultPromise).resolves.toEqual({ ok: true });
+    connection.close();
+  });
 });