feat(daemon): add IPC communication and health checks #84

galligan · 2026-01-23T05:42:21Z

Add daemon communication and monitoring infrastructure:

createIpcServer(): Unix socket server with JSON protocol
createIpcClient(): Client for sending requests to daemon
createHealthChecker(): Parallel health check execution
Request/response protocol with timeouts
Handler registration for custom IPC commands
Health status aggregation with pass/fail thresholds
Comprehensive test coverage (52 tests)

Co-Authored-By: Claude Opus 4.5 noreply@anthropic.com

Contributes to #56

galligan · 2026-01-23T05:42:41Z

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greptile-apps · 2026-01-23T21:08:09Z

Greptile Summary

Implements comprehensive IPC communication infrastructure with Unix socket server/client for daemon processes
Adds parallel health check execution system with status aggregation and dynamic registration
Creates structured daemon package API with proper TypeScript contracts and TDD-first implementation approach

Important Files Changed

Filename	Overview
packages/daemon/src/ipc.ts	Implements Unix socket IPC communication with message buffering, request-response protocol, and connection lifecycle management
packages/daemon/src/health.ts	Health checking framework with parallel execution, error aggregation, and dynamic registration capabilities

Confidence score: 4/5

This PR is safe to merge with only minor risks related to IPC implementation complexity
Score reflects comprehensive test coverage (52 tests) and adherence to project standards, but Unix socket message buffering and error handling logic requires careful review
Pay close attention to packages/daemon/src/ipc.ts message buffering logic and connection cleanup mechanisms

Sequence Diagram

sequenceDiagram
    participant Client as IpcClient
    participant Socket as Unix Socket
    participant Server as IpcServer
    participant Handler as MessageHandler

    Client->>Socket: "connect()"
    Socket->>Server: "open connection"
    Server->>Socket: "accept connection"
    Socket->>Client: "connection established"

    Client->>Socket: "send(message)"
    Socket->>Server: "data received"
    Server->>Server: "parse JSON message"
    Server->>Handler: "call handler(payload)"
    Handler->>Server: "return response"
    Server->>Socket: "write JSON response"
    Socket->>Client: "response received"
    Client->>Client: "resolve pending request"

greptile-apps

_{6 files reviewed, 4 comments}

_{Edit Code Review Agent Settings | Greptile}

greptile-apps · 2026-01-23T21:08:06Z

packages/daemon/src/__tests__/lifecycle.test.ts

+		expect(daemon.state).toBe("stopped");
+		// The daemon should have handled the timeout gracefully
+		// Either returning an error or completing anyway
+		expect(result.isOk() || result.isErr()).toBe(true);


logic: This assertion doesn't verify the expected behavior - should check for specific timeout error rather than accepting any result

Prompt To Fix With AI

This is a comment left during a code review. Path: packages/daemon/src/__tests__/lifecycle.test.ts Line: 382:382 Comment: **logic:** This assertion doesn't verify the expected behavior - should check for specific timeout error rather than accepting any result How can I resolve this? If you propose a fix, please make it concise.

greptile-apps · 2026-01-23T21:08:07Z

packages/daemon/src/__tests__/ipc.test.ts

+		const client = createIpcClient(socketPath);
+		await client.connect();
+
+		const response = await client.send<{ echo: string }>({ hello: "world" });


logic: Type annotation inconsistent - expecting { echo: string } but receiving { echo: object }

Suggested change

const response = await client.send<{ echo: string }>({ hello: "world" });

const response = await client.send<{ echo: object }>({ hello: "world" });

Prompt To Fix With AI

This is a comment left during a code review. Path: packages/daemon/src/__tests__/ipc.test.ts Line: 216:216 Comment: **logic:** Type annotation inconsistent - expecting `{ echo: string }` but receiving `{ echo: object }` ```suggestion const response = await client.send<{ echo: object }>({ hello: "world" }); ``` How can I resolve this? If you propose a fix, please make it concise.

greptile-apps · 2026-01-23T21:08:08Z

packages/daemon/src/__tests__/ipc.test.ts

+	it("handles malformed messages gracefully", async () => {
+		const socketPath = join(testDir, "test.sock");
+		const server = createIpcServer(socketPath);
+
+		server.onMessage(async (msg) => {
+			return { received: msg };
+		});
+
+		await server.listen();
+
+		// Server should handle invalid JSON without crashing
+		// This test verifies robustness
+
+		const client = createIpcClient(socketPath);
+		await client.connect();
+
+		// Valid message should still work
+		const response = await client.send<{ received: unknown }>({ valid: true });
+		expect(response.received).toEqual({ valid: true });
+
+		client.close();
+		await server.close();
+	});


logic: Test doesn't actually verify malformed message handling - only sends valid JSON. Should this test send actual malformed JSON to verify the server handles it gracefully?

Prompt To Fix With AI

This is a comment left during a code review. Path: packages/daemon/src/__tests__/ipc.test.ts Line: 394:416 Comment: **logic:** Test doesn't actually verify malformed message handling - only sends valid JSON. Should this test send actual malformed JSON to verify the server handles it gracefully? How can I resolve this? If you propose a fix, please make it concise.

greptile-apps · 2026-01-23T21:08:08Z

packages/daemon/src/ipc.ts

+		},
+
+		close(): void {
+			if (!isConnected && !socket) return;


logic: Logic should use OR (||) instead of AND (&&) - function should return early if already disconnected

Suggested change

if (!isConnected && !socket) return;

if (!isConnected || !socket) return;

Prompt To Fix With AI

This is a comment left during a code review. Path: packages/daemon/src/ipc.ts Line: 412:412 Comment: **logic:** Logic should use OR (||) instead of AND (&&) - function should return early if already disconnected ```suggestion if (!isConnected || !socket) return; ``` How can I resolve this? If you propose a fix, please make it concise.

galligan · 2026-01-23T21:58:58Z

IPC framing is buffered per-connection: server/client accumulate into a buffer, split on newlines, and only JSON.parse complete frames. Pre-push tests passed.

galligan · 2026-01-23T23:10:52Z

Restacked after downstack update (formatRelative test stabilization); no additional changes in this PR.

Add daemon communication and monitoring infrastructure: - createIpcServer(): Unix socket server with JSON protocol - createIpcClient(): Client for sending requests to daemon - createHealthChecker(): Parallel health check execution - Request/response protocol with timeouts - Handler registration for custom IPC commands - Health status aggregation with pass/fail thresholds - Comprehensive test coverage (52 tests) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

galligan · 2026-01-24T03:14:17Z

Addressed greptile notes: tightened shutdown timeout assertion, corrected typed IPC response shape, added malformed JSON coverage via raw socket, and fixed client close guard to return when disconnected. Restacked and resubmitted.

galligan force-pushed the p3-22/daemon/ipc-health branch from c4267ec to e7c2227 Compare January 23, 2026 11:45

galligan force-pushed the p3-21/daemon/types-lifecycle branch from 08412d8 to 8754855 Compare January 23, 2026 11:58

galligan force-pushed the p3-22/daemon/ipc-health branch from e7c2227 to 7cb5483 Compare January 23, 2026 11:58

galligan added the enhancement New feature or request label Jan 23, 2026

galligan marked this pull request as ready for review January 23, 2026 12:01

galligan force-pushed the p3-22/daemon/ipc-health branch from 7cb5483 to 77259f9 Compare January 23, 2026 16:03

galligan force-pushed the p3-21/daemon/types-lifecycle branch from 2c791c5 to dfbbb85 Compare January 23, 2026 19:46

galligan force-pushed the p3-22/daemon/ipc-health branch from 77259f9 to 445f46f Compare January 23, 2026 19:46

This was referenced Jan 23, 2026

fix(cli): enforce cursor TTL #114

Open

fix(tests): remove placeholder tests #113

Open

greptile-apps bot reviewed Jan 23, 2026

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galligan mentioned this pull request Jan 23, 2026

chore(gitattributes): prefer ours for bun lockfiles #115

Open

galligan changed the base branch from p3-21/daemon/types-lifecycle to graphite-base/84 January 23, 2026 21:55

galligan force-pushed the graphite-base/84 branch from dfbbb85 to 2f370ee Compare January 23, 2026 21:58

galligan force-pushed the p3-22/daemon/ipc-health branch from 445f46f to c054bed Compare January 23, 2026 21:58

galligan changed the base branch from graphite-base/84 to p3-21/daemon/types-lifecycle January 23, 2026 21:58

galligan force-pushed the p3-21/daemon/types-lifecycle branch from 2f370ee to a1e44c2 Compare January 23, 2026 23:09

galligan force-pushed the p3-22/daemon/ipc-health branch from c054bed to 4ea0f4d Compare January 23, 2026 23:09

galligan changed the base branch from p3-21/daemon/types-lifecycle to graphite-base/84 January 24, 2026 03:08

galligan added 2 commits January 23, 2026 22:12

fix(daemon): harden ipc tests and disconnect handling

9af288c

fix(daemon): adjust ipc malformed test

1bf4162

galligan force-pushed the graphite-base/84 branch from a1e44c2 to 19a7f81 Compare January 24, 2026 03:14

galligan force-pushed the p3-22/daemon/ipc-health branch from 4ea0f4d to 1bf4162 Compare January 24, 2026 03:14

galligan changed the base branch from graphite-base/84 to p3-21/daemon/types-lifecycle January 24, 2026 03:14

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feat(daemon): add IPC communication and health checks #84

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Important Files Changed

Sequence Diagram

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	const response = await client.send<{ echo: string }>({ hello: "world" });
	const response = await client.send<{ echo: object }>({ hello: "world" });

	if (!isConnected && !socket) return;
	if (!isConnected \|\| !socket) return;

feat(daemon): add IPC communication and health checks #84

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Greptile Summary

Important Files Changed

Confidence score: 4/5

Sequence Diagram

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