fix(coding-agent): use async operations in tools

packages/coding-agent/test/file-mutation-queue.test.ts

@@ -10,6 +10,18 @@ function delay(ms: number): Promise<void> {
 	return new Promise((resolve) => setTimeout(resolve, ms));
 }
 
+function createDeferred(): { promise: Promise<void>; resolve: () => void } {
+	let resolve!: () => void;
+	const promise = new Promise<void>((promiseResolve) => {
+		resolve = promiseResolve;
+	});
+	return { promise, resolve };
+}
+
+async function resolvesWithin(promise: Promise<unknown>, ms: number): Promise<boolean> {
+	return Promise.race([promise.then(() => true), delay(ms).then(() => false)]);
+}
+
 const tempDirs: string[] = [];
 
 async function createTempDir(): Promise<string> {
@@ -160,4 +172,103 @@ describe("built-in edit and write tools", () => {
 		const content = await readFile(filePath, "utf8");
 		expect(content).toBe("replacement\n");
 	});
+
+	it("keeps write queue locked while an aborted write is still in flight", async () => {
+		const dir = await createTempDir();
+		const filePath = join(dir, "abort-write.txt");
+		const firstWriteStarted = createDeferred();
+		const finishFirstWrite = createDeferred();
+		const secondWriteStarted = createDeferred();
+		let firstWriteSettled = false;
+
+		const writeTool = createWriteTool(dir, {
+			operations: {
+				mkdir: async () => {},
+				writeFile: async (path, content) => {
+					if (content === "first\n") {
+						firstWriteStarted.resolve();
+						await finishFirstWrite.promise;
+						await writeFile(path, content, "utf8");
+						firstWriteSettled = true;
+						return;
+					}
+
+					if (content === "second\n") {
+						expect(firstWriteSettled).toBe(true);
+						secondWriteStarted.resolve();
+					}
+					await writeFile(path, content, "utf8");
+				},
+			},
+		});
+
+		const controller = new AbortController();
+		const firstWrite = writeTool.execute("call-1", { path: filePath, content: "first\n" }, controller.signal);
+		await firstWriteStarted.promise;
+		controller.abort();
+
+		const secondWrite = writeTool.execute("call-2", { path: filePath, content: "second\n" });
+		expect(await resolvesWithin(secondWriteStarted.promise, 20)).toBe(false);
+
+		finishFirstWrite.resolve();
+		await expect(firstWrite).rejects.toThrow("Operation aborted");
+		await secondWrite;
+
+		const content = await readFile(filePath, "utf8");
+		expect(content).toBe("second\n");
+	});
+
+	it("keeps edit queue locked while an aborted edit write is still in flight", async () => {
+		const dir = await createTempDir();
+		const filePath = join(dir, "abort-edit.txt");
+		await writeFile(filePath, "alpha\nbeta\n", "utf8");
+		const firstWriteStarted = createDeferred();
+		const finishFirstWrite = createDeferred();
+		const secondWriteStarted = createDeferred();
+		let firstWriteSettled = false;
+
+		const editTool = createEditTool(dir, {
+			operations: {
+				access,
+				readFile,
+				writeFile: async (path, content) => {
+					if (content === "ALPHA\nbeta\n") {
+						firstWriteStarted.resolve();
+						await finishFirstWrite.promise;
+						await writeFile(path, content, "utf8");
+						firstWriteSettled = true;
+						return;
+					}
+
+					if (content === "ALPHA\nBETA\n" || content === "alpha\nBETA\n") {
+						expect(firstWriteSettled).toBe(true);
+						secondWriteStarted.resolve();
+					}
+					await writeFile(path, content, "utf8");
+				},
+			},
+		});
+
+		const controller = new AbortController();
+		const firstEdit = editTool.execute(
+			"call-1",
+			{ path: filePath, edits: [{ oldText: "alpha", newText: "ALPHA" }] },
+			controller.signal,
+		);
+		await firstWriteStarted.promise;
+		controller.abort();
+
+		const secondEdit = editTool.execute("call-2", {
+			path: filePath,
+			edits: [{ oldText: "beta", newText: "BETA" }],
+		});
+		expect(await resolvesWithin(secondWriteStarted.promise, 20)).toBe(false);
+
+		finishFirstWrite.resolve();
+		await expect(firstEdit).rejects.toThrow("Operation aborted");
+		await secondEdit;
+
+		const content = await readFile(filePath, "utf8");
+		expect(content).toBe("ALPHA\nBETA\n");
+	});
 });