fix: create-package script (#5123)

## Explanation

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This PR addresses a bug in the yarn `create-package` script introduced
in [this
change](https://github.com/MetaMask/core/pull/3672/files#diff-3424bcceb4f9219f700e2bd2da507f2c742767c7a30f6be5512f62d3b44ffd7aR97),
where `fstatSync` was replaced with `await
fs.stat(packagePath)).isDirectory()`.

The issue arises because fs.stat now throws an `ENOENT` error if the
packagePath is empty. To resolve this, the script has been updated to
handle empty paths gracefully, ensuring the process works as expected
when creating new packages.

## References

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## Changelog

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## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've highlighted breaking changes using the "BREAKING" category
above as appropriate
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

Author: cryptodev-2s

scripts/create-package/utils.test.ts

@@ -87,9 +87,10 @@ describe('create-package/utils', () => {
         nodeVersions: '>=18.0.0',
       };
 
-      (fs.promises.stat as jest.Mock).mockResolvedValueOnce({
-        isDirectory: () => false,
-      });
+      const mockError = new Error('Not found') as NodeJS.ErrnoException;
+      mockError.code = 'ENOENT';
+
+      jest.spyOn(fs.promises, 'stat').mockRejectedValue(mockError);
 
       (fsUtils.readAllFiles as jest.Mock).mockResolvedValueOnce({
         'src/index.ts': 'export default 42;',
@@ -170,9 +171,7 @@ describe('create-package/utils', () => {
         nodeVersions: '20.0.0',
       };
 
-      (fs.promises.stat as jest.Mock).mockResolvedValueOnce({
-        isDirectory: () => true,
-      });
+      (fs.promises.stat as jest.Mock).mockResolvedValue({});
 
       await expect(
         finalizeAndWriteData(packageData, monorepoFileData),
@@ -181,5 +180,34 @@ describe('create-package/utils', () => {
       expect(fs.promises.mkdir).not.toHaveBeenCalled();
       expect(fs.promises.writeFile).not.toHaveBeenCalled();
     });
+
+    it('throws if fs.stat fails with an error other than ENOENT', async () => {
+      const mockError = new Error('Permission denied') as NodeJS.ErrnoException;
+      mockError.code = 'EACCES';
+
+      jest.spyOn(fs.promises, 'stat').mockRejectedValue(mockError);
+
+      const packageData: PackageData = {
+        name: '@metamask/foo',
+        description: 'A foo package.',
+        directoryName: 'foo',
+        nodeVersions: '20.0.0',
+        currentYear: '2023',
+      };
+
+      const monorepoFileData = {
+        tsConfig: {
+          references: [{ path: './packages/bar' }],
+        },
+        tsConfigBuild: {
+          references: [{ path: './packages/bar' }],
+        },
+        nodeVersions: '20.0.0',
+      };
+
+      await expect(
+        finalizeAndWriteData(packageData, monorepoFileData),
+      ).rejects.toThrow('Permission denied');
+    });
   });
 });

scripts/create-package/utils.ts

@@ -94,8 +94,13 @@ export async function finalizeAndWriteData(
   monorepoFileData: MonorepoFileData,
 ) {
   const packagePath = path.join(PACKAGES_PATH, packageData.directoryName);
-  if ((await fs.stat(packagePath)).isDirectory()) {
+  try {
+    await fs.stat(packagePath);
     throw new Error(`The package directory already exists: ${packagePath}`);
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code !== 'ENOENT') {
+      throw error;
+    }
   }
 
   console.log('Writing package and monorepo files...');
@@ -136,7 +141,7 @@ async function writeJsonFile(
 ): Promise<void> {
   await fs.writeFile(
     filePath,
-    prettierFormat(fileContent, { ...prettierRc, parser: 'json' }),
+    await prettierFormat(fileContent, { ...prettierRc, parser: 'json' }),
   );
 }