fix(cli): Destroy the worker pool after the initial compilation

.changeset/quick-pumas-retire.md

@@ -0,0 +1,5 @@
+---
+"@swc/cli": patch
+---
+
+fix(cli): Destroy the worker pool after the initial compilation

packages/cli/src/swc/__tests__/dir.test.ts

@@ -0,0 +1,76 @@
+import { swcDir } from "../index";
+
+jest.mock("../compile", () => ({
+    outputResult: jest.fn(),
+}));
+
+let mockRun: any;
+const mockDestroy = jest.fn();
+
+jest.mock("piscina", () => ({
+    __esModule: true,
+    default: class {
+        run(...args: any[]) {
+            return mockRun(...args);
+        }
+        destroy() {
+            return mockDestroy();
+        }
+    },
+}));
+
+const cliOptions: any = {
+    outDir: "./.temp/",
+    watch: false,
+    filenames: ["./src/swcx/"],
+    extensions: [".ts"],
+    stripLeadingPaths: true,
+    sync: false,
+};
+const swcOptions: any = {
+    jsc: {
+        target: "esnext",
+        externalHelpers: false,
+    },
+    module: {
+        type: "commonjs",
+    },
+};
+
+describe("dir worker pool", () => {
+    beforeEach(() => {
+        mockDestroy.mockClear();
+    });
+
+    it("should destroy the pool after a successful compilation", async () => {
+        mockRun = () => Promise.resolve(1); // mock compile success
+
+        const onSuccess = jest.fn();
+        const onFail = jest.fn();
+
+        await swcDir({
+            cliOptions,
+            swcOptions,
+            callbacks: { onSuccess, onFail },
+        });
+
+        expect(onSuccess.mock.calls).toHaveLength(1);
+        expect(mockDestroy.mock.calls).toHaveLength(1);
+    });
+
+    it("should destroy the pool when a file fails to compile", async () => {
+        mockRun = () => Promise.reject(new Error("fail")); // mock compile fail
+
+        const onSuccess = jest.fn();
+        const onFail = jest.fn();
+
+        await swcDir({
+            cliOptions,
+            swcOptions,
+            callbacks: { onSuccess, onFail },
+        });
+
+        expect(onFail.mock.calls).toHaveLength(1);
+        expect(mockDestroy.mock.calls).toHaveLength(1);
+    });
+});

packages/cli/src/swc/dir.ts

@@ -156,26 +156,28 @@ async function initialCompilation(
                     handleCopy(file, outDir, stripLeadingPaths)
                 )
             ),
-        ]).then(([compiled, copied]) => {
-            compiled.forEach((result, index) => {
-                const filename = compilable[index];
-                if (result.status === "fulfilled") {
-                    results.set(filename, result.value);
-                } else {
-                    results.set(filename, CompileStatus.Failed);
-                    reasons.set(filename, result.reason.message);
-                }
-            });
+        ])
+            .then(([compiled, copied]) => {
+                compiled.forEach((result, index) => {
+                    const filename = compilable[index];
+                    if (result.status === "fulfilled") {
+                        results.set(filename, result.value);
+                    } else {
+                        results.set(filename, CompileStatus.Failed);
+                        reasons.set(filename, result.reason.message);
+                    }
+                });
 
-            copied.forEach((result, index) => {
-                const filename = copyable[index];
-                if (result.status === "fulfilled") {
-                    results.set(filename, result.value);
-                } else {
-                    results.set(filename, CompileStatus.Failed);
-                }
-            });
-        });
+                copied.forEach((result, index) => {
+                    const filename = copyable[index];
+                    if (result.status === "fulfilled") {
+                        results.set(filename, result.value);
+                    } else {
+                        results.set(filename, CompileStatus.Failed);
+                    }
+                });
+            })
+            .finally(() => workers.destroy());
     }
     const end = process.hrtime(start);