test: comprehensive integration + coverage tests for session-coordinator and session-runtime

src/adapters/acp/acp-adapter-coverage.test.ts

@@ -0,0 +1,66 @@
+/**
+ * Coverage tests targeting lines 62-63 of acp-adapter.ts:
+ * the branch where spawn returns a child process with missing stdin/stdout pipes.
+ *
+ * Branch: `if (!child.stdin || !child.stdout) { child.kill(); throw ... }`
+ */
+
+import type { ChildProcess } from "node:child_process";
+import { EventEmitter } from "node:events";
+import { describe, expect, it, vi } from "vitest";
+import type { SpawnFn } from "./acp-adapter.js";
+import { AcpAdapter } from "./acp-adapter.js";
+
+function makeMinimalChild(overrides: Partial<{ stdin: unknown; stdout: unknown }>): ChildProcess {
+  const child = new EventEmitter() as ChildProcess;
+  const kill = vi.fn((_signal?: string) => true);
+  Object.assign(child, {
+    stdin: overrides.stdin ?? null,
+    stdout: overrides.stdout ?? null,
+    stderr: new EventEmitter(),
+    pid: 99999,
+    killed: false,
+    kill,
+  });
+  return child;
+}
+
+describe("AcpAdapter — missing stdio pipes (lines 62-63)", () => {
+  it("kills child and throws when stdin is null", async () => {
+    // Spawn returns a child whose stdin is null (e.g. stdio: 'ignore')
+    const child = makeMinimalChild({ stdin: null, stdout: new EventEmitter() });
+    const spawnFn: SpawnFn = vi.fn(() => child);
+
+    const adapter = new AcpAdapter(spawnFn);
+    await expect(adapter.connect({ sessionId: "sess-no-stdin" })).rejects.toThrow(
+      "Failed to open stdio pipes for ACP subprocess",
+    );
+
+    expect(child.kill).toHaveBeenCalled();
+  });
+
+  it("kills child and throws when stdout is null", async () => {
+    // Spawn returns a child whose stdout is null
+    const child = makeMinimalChild({ stdin: new EventEmitter(), stdout: null });
+    const spawnFn: SpawnFn = vi.fn(() => child);
+
+    const adapter = new AcpAdapter(spawnFn);
+    await expect(adapter.connect({ sessionId: "sess-no-stdout" })).rejects.toThrow(
+      "Failed to open stdio pipes for ACP subprocess",
+    );
+
+    expect(child.kill).toHaveBeenCalled();
+  });
+
+  it("kills child and throws when both stdin and stdout are null", async () => {
+    const child = makeMinimalChild({ stdin: null, stdout: null });
+    const spawnFn: SpawnFn = vi.fn(() => child);
+
+    const adapter = new AcpAdapter(spawnFn);
+    await expect(adapter.connect({ sessionId: "sess-no-pipes" })).rejects.toThrow(
+      "Failed to open stdio pipes for ACP subprocess",
+    );
+
+    expect(child.kill).toHaveBeenCalled();
+  });
+});