chore(utils): extend fs utils with createCacheReadStream and statCach…

lib/util/fs/index.spec.ts

@@ -8,6 +8,7 @@ import {
   cachePathExists,
   cachePathIsFile,
   chmodLocalFile,
+  createCacheReadStream,
   createCacheWriteStream,
   deleteLocalFile,
   ensureCacheDir,
@@ -32,6 +33,7 @@ import {
   readSystemFile,
   renameLocalFile,
   rmCache,
+  statCacheFile,
   statLocalFile,
   writeLocalFile,
   writeSystemFile,
@@ -332,6 +334,29 @@ describe('util/fs/index', () => {
     });
   });
 
+  describe('createCacheReadStream', () => {
+    it('creates read stream', async () => {
+      const path = `${cacheDir}/file.txt`;
+      const fileContent = 'foo';
+      await fs.outputFile(path, fileContent);
+
+      const stream = createCacheReadStream('file.txt');
+      expect(stream).toBeInstanceOf(fs.ReadStream);
+
+      let data = '';
+      stream.on('data', (chunk) => {
+        data += chunk.toString();
+      });
+
+      await new Promise((resolve, reject) => {
+        stream.on('end', resolve);
+        stream.on('error', reject);
+      });
+
+      expect(data).toBe(fileContent);
+    });
+  });
+
   describe('localPathIsFile', () => {
     it('returns true for file', async () => {
       const path = `${localDir}/file.txt`;
@@ -431,6 +456,17 @@ describe('util/fs/index', () => {
     });
   });
 
+  describe('statCacheFile', () => {
+    it('returns stat object', async () => {
+      expect(await statCacheFile('foo')).toBeNull();
+
+      await fs.outputFile(`${cacheDir}/foo`, 'foobar');
+      const stat = await statCacheFile('foo');
+      expect(stat).toBeTruthy();
+      expect(stat!.isFile()).toBeTrue();
+    });
+  });
+
   describe('listCacheDir', () => {
     it('lists directory', async () => {
       await fs.outputFile(`${cacheDir}/foo/bar.txt`, 'foobar');

lib/util/fs/index.ts

@@ -176,6 +176,11 @@ export function createCacheWriteStream(path: string): fs.WriteStream {
   return fs.createWriteStream(fullPath);
 }
 
+export function createCacheReadStream(path: string): fs.ReadStream {
+  const fullPath = ensureCachePath(path);
+  return fs.createReadStream(fullPath);
+}
+
 export async function localPathIsFile(pathName: string): Promise<boolean> {
   const path = ensureLocalPath(pathName);
   try {
@@ -249,6 +254,17 @@ export async function statLocalFile(
   }
 }
 
+export async function statCacheFile(
+  pathName: string,
+): Promise<fs.Stats | null> {
+  const path = ensureCachePath(pathName);
+  try {
+    return await fs.stat(path);
+  } catch (_) {
+    return null;
+  }
+}
+
 export function listCacheDir(
   path: string,
   options: { recursive: boolean } = { recursive: false },