test(utils): enhance vitestFsMock with unionfs for improved file system handling

Author: radist2s

packages/asyncapi-typescript-plugin/package.json

@@ -50,7 +50,6 @@
     "eslint": "^9.39.1",
     "memfs": "^4.56.10",
     "rimraf": "^6.1.2",
-    "unionfs": "^4.6.0",
     "vitest": "^3.2.4"
   },
   "files": [

packages/test-utils/src/vitestFsMock.ts

@@ -1,23 +1,49 @@
 import { vi } from 'vitest';
 
-const createMemFs = vi.hoisted(
-  () => async (_fsOriginal: typeof import('node:fs')) => {
+const createUnionFs = vi.hoisted(
+  () => async (fsOriginal: typeof import('node:fs')) => {
     const { Volume, createFsFromVolume } = await import('memfs');
+    const { ufs } = await import('unionfs');
 
-    return createFsFromVolume(Volume.fromJSON({}));
+    const memFs = createFsFromVolume(Volume.fromJSON({}));
+    const union = ufs.use(memFs as never).use(fsOriginal as never);
+
+    if (union.promises && typeof fsOriginal.promises?.rm === 'function') {
+      const memFsPromises = (
+        memFs as {
+          promises?: { rm?: (path: string, options?: object) => Promise<void> };
+        }
+      ).promises;
+      (
+        union.promises as {
+          rm: (path: string, options?: object) => Promise<void>;
+        }
+      ).rm = async (path, options) => {
+        if (typeof memFsPromises?.rm === 'function') {
+          try {
+            return await memFsPromises.rm(path, options);
+          } catch {
+            return await fsOriginal.promises.rm(path, options);
+          }
+        }
+        return await fsOriginal.promises.rm(path, options);
+      };
+    }
+
+    return union;
   }
 );
 
 vi.mock('node:fs', async (importOriginal) => {
   return {
-    default: await createMemFs(
+    default: await createUnionFs(
       await importOriginal<typeof import('node:fs')>()
     ),
   };
 });
 
 vi.mock('fs', async (importOriginal) => {
   return {
-    default: await createMemFs(await importOriginal<typeof import('fs')>()),
+    default: await createUnionFs(await importOriginal<typeof import('fs')>()),
   };
 });

yarn.lock

@@ -4745,7 +4745,6 @@ __metadata:
     openapi-typescript: "npm:^7.10.1"
     rimraf: "npm:^6.1.2"
     typescript: "npm:^5.6.2"
-    unionfs: "npm:^4.6.0"
     vitest: "npm:^3.2.4"
   languageName: unknown
   linkType: soft