mock-gcs

library2.1.0jsnpmunverified

mock-gcs is a TypeScript library providing mock implementations of Google Cloud Storage SDK classes (Storage, Bucket, File) for testing and development. Version 2.1.0 supports most basic features like bucket and file operations, upload/download, signed URLs, and error simulation via mockErrorOnce. It also exports TypeScript interfaces (IStorage, IBucket, IFile) to facilitate type-safe code that works with both @google-cloud/storage and mock-gcs. The library is actively maintained and encourages community contributions for missing methods.

testing

npm install mock-gcs

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · MOCK-GCS

mock-gcs

testingjavascriptv2.1.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

MockStorage

✓ import { MockStorage } from 'mock-gcs'

✗ const mockGcs = require('mock-gcs'); const MockStorage = mockGcs.MockStorage;

ESM-only; named export. CommonJS require can be used but is not tree-shakable.

IStorage

✓ import { IStorage } from 'mock-gcs'

✗ import { Storage } from '@google-cloud/storage'; // wrong, IStorage is the interface

Use IStorage for type-safe mocking instead of using the real Storage type.

Bucket

✓ import { MockStorage } from 'mock-gcs'; const bucket = new MockStorage().bucket('name');

✗ import { Bucket } from 'mock-gcs'; // Bucket is not exported directly

Bucket class is not exported; use storage.bucket() method.

Demonstrates how to use MockStorage in a class that accepts IStorage for type safety, then test with mock.

import { MockStorage } from 'mock-gcs'; import { Storage } from '@google-cloud/storage'; class FileProcessor { constructor(private storage: IStorage) {} async save(path: string, content: string) { const file = this.storage.bucket('my-bucket').file(path); await file.save(content); } async download(path: string): Promise<string> { const file = this.storage.bucket('my-bucket').file(path); const [data] = await file.download(); return data.toString(); } } // In test: const storage = new MockStorage(); const processor = new FileProcessor(storage); await processor.save('test.txt', 'hello'); const result = await processor.download('test.txt'); console.log(result); // 'hello'

Debug

Known issues

breakingVersion 2.x changed from CommonJS to ESM-only; require() may need dynamic import.

fix

Use import syntax or const { MockStorage } = await import('mock-gcs');

affects: >=2.0.0

gotchaNot all GCS methods are implemented; see README for list.

fix

Check available methods in documentation; submit PR for missing ones.

affects: >=0.0.0

gotchaPromise-based methods only; no callback support.

fix

Use async/await or Promise.then().

affects: >=0.0.0

gotchamockErrorOnce only works for methods that were previously called; subsequent calls are normal.

fix

Call mockErrorOnce before the method you want to fail.

affects: >=1.0.0

Errors

Common errors & fixes

Module not found: Can't resolve 'mock-gcs'

Package not installed or missing in package.json.

fix

npm install mock-gcs

Class constructor MockStorage cannot be invoked without 'new'

Importing as default or calling without new.

fix

Use: const storage = new MockStorage(); // not MockStorage() without new

Property 'mockErrorOnce' does not exist on type 'File'

mocked file object not created via MockStorage; using real @google-cloud/storage types.

fix

Use IFile type or cast to any: (file as any).mockErrorOnce('method', error)

Upgrade

Version history

2.1.0latest on npm

Audit

Dependencies

@google-cloud/storageoptionalProvides the real GCS SDK interfaces being mocked; often used alongside mock-gcs in tests.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/aldipermanaetikaputra/mock-gcs ↗

packagemock-gcs ↗

homepagehttps://github.com/aldipermanaetikaputra/mock-gcs ↗