feat(storage): support delete source objects on compose

storage/composeFile.js

@@ -0,0 +1,74 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+'use strict';
+
+/**
+ * This application demonstrates how to compose/combine multiple files into a
+ * single destination file with the Google Cloud Storage API.
+ *
+ * For more information, see the README.md under /storage and the documentation
+ * at https://cloud.google.com/storage/docs.
+ */
+
+async function main(
+  bucketName = 'my-bucket',
+  firstFileName = 'first.txt',
+  secondFileName = 'second.txt',
+  destinationFileName = 'destination.txt',
+  deleteSourceObjects = false
+) {
+  // [START storage_compose_file]
+  /**
+   * TODO(developer): Uncomment the following lines before running the sample.
+   */
+  // const bucketName = 'your-unique-bucket-name';
+  // const firstFileName = 'first.txt';
+  // const secondFileName = 'second.txt';
+  // const destinationFileName = 'destination.txt';
+  // const deleteSourceObjects = false;
+
+  // Imports the Google Cloud client library
+  const {Storage} = require('@google-cloud/storage');
+
+  // Creates a client
+  const storage = new Storage();
+
+  async function composeFile() {
+    const bucket = storage.bucket(bucketName);
+    const sources = [firstFileName, secondFileName];
+
+    await bucket.combine(sources, destinationFileName);
+
+    const deleteSources = String(deleteSourceObjects) === 'true';
+    if (deleteSources) {
+      await Promise.all(sources.map(name => bucket.file(name).delete()));
+    }
+
+    const deletionMessage = deleteSources
+      ? ' and the source objects were deleted.'
+      : '.';
+    console.log(
+      `New composite file ${destinationFileName} was created by combining ${sources.join(', ')}${deletionMessage}`
+    );
+  }
+
+  await composeFile();
+  // [END storage_compose_file]
+}
+
+main(...process.argv.slice(2)).catch(err => {
+  console.error(err);
+  process.exitCode = 1;
+});

storage/system-test/files.test.js

@@ -146,6 +146,52 @@ describe('file', () => {
       await bucket.file(noContextFileName).delete();
     });
   });
+
+  describe('compose file', () => {
+    it('should combine multiple files into one new file and optionally delete source objects', async () => {
+      const firstFileName = 'first.txt';
+      const secondFileName = 'second.txt';
+      const destinationFileName = 'destination.txt';
+
+      // upload test.txt twice
+      await bucket.upload(filePath, {destination: firstFileName});
+      await bucket.upload(filePath, {destination: secondFileName});
+
+      // Test with deleteSourceObjects = false
+      let output = execSync(
+        `node composeFile.js ${bucketName} ${firstFileName} ${secondFileName} ${destinationFileName} false`
+      );
+      assert.include(
+        output,
+        `New composite file ${destinationFileName} was created by combining ${firstFileName}, ${secondFileName}.`
+      );
+
+      let [destExists] = await bucket.file(destinationFileName).exists();
+      assert.strictEqual(destExists, true);
+      let [firstExists] = await bucket.file(firstFileName).exists();
+      assert.strictEqual(firstExists, true);
+      let [secondExists] = await bucket.file(secondFileName).exists();
+      assert.strictEqual(secondExists, true);
+
+      await bucket.file(destinationFileName).delete();
+
+      // Test with deleteSourceObjects = true
+      output = execSync(
+        `node composeFile.js ${bucketName} ${firstFileName} ${secondFileName} ${destinationFileName} true`
+      );
+      assert.include(
+        output,
+        `New composite file ${destinationFileName} was created by combining ${firstFileName}, ${secondFileName} and the source objects were deleted.`
+      );
+
+      [destExists] = await bucket.file(destinationFileName).exists();
+      assert.strictEqual(destExists, true);
+      [firstExists] = await bucket.file(firstFileName).exists();
+      assert.strictEqual(firstExists, false);
+      [secondExists] = await bucket.file(secondFileName).exists();
+      assert.strictEqual(secondExists, false);
+    });
+  });
 });
 
 function generateName() {