fix: handle cross-device cache locations (#336)

Co-authored-by: Cacie Prins <[email protected]>
Co-authored-by: Kevin Cui <[email protected]>

Author: 3 people

src/Cache.ts

@@ -49,7 +49,22 @@ export class Cache {
       d('* Replacing existing file');
       await fs.promises.rm(cachePath, { recursive: true, force: true });
     }
-    await fs.promises.rename(currentPath, cachePath);
+
+    try {
+      await fs.promises.rename(currentPath, cachePath);
+    } catch (err) {
+      if ((err as NodeJS.ErrnoException).code === 'EXDEV') {
+        // Cross-device link, fallback to copy and delete
+        await fs.promises.cp(currentPath, cachePath, {
+          force: true,
+          recursive: true,
+          verbatimSymlinks: true,
+        });
+        await fs.promises.rm(currentPath, { force: true, recursive: true });
+      } else {
+        throw err;
+      }
+    }
 
     return cachePath;
   }

test/Cache.spec.ts

@@ -3,7 +3,7 @@ import os from 'node:os';
 import path from 'node:path';
 import util from 'node:util';
 
-import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 
 import { Cache } from '../src/Cache';
 
@@ -88,5 +88,25 @@ describe('Cache', () => {
       expect(cachePath.startsWith(cacheDir)).toEqual(true);
       expect(await util.promisify(fs.readFile)(cachePath, 'utf8')).toEqual('example content');
     });
+
+    it('can handle cross-device cache paths', async () => {
+      const error: NodeJS.ErrnoException = new Error('EXDEV: cross-device link not permitted');
+      error.code = 'EXDEV';
+
+      const spy = vi.spyOn(fs.promises, 'rename').mockRejectedValueOnce(error);
+
+      try {
+        const originalFolder = path.resolve(cacheDir, sanitizedDummyUrl);
+        await fs.promises.mkdir(originalFolder, { recursive: true });
+        const originalPath = path.resolve(originalFolder, 'original.txt');
+        await util.promisify(fs.writeFile)(originalPath, 'example content');
+        const cachePath = await cache.putFileInCache(dummyUrl, originalPath, 'test.txt');
+        expect(cachePath.startsWith(cacheDir)).toEqual(true);
+        expect(await util.promisify(fs.readFile)(cachePath, 'utf8')).toEqual('example content');
+        expect(spy).toHaveBeenCalled();
+      } finally {
+        spy.mockRestore();
+      }
+    });
   });
 });