How to stubbing S3 upload in Node.js?
I'm using Mocha and Sinon. And I have a file that exports a class instance that including the upload method. It looks like this:
// storage.ts
import * as AWS from 'aws-sdk';
import archiver from 'archiver';
import retry from 'bluebird-retry';
export class Storage {
private readonly s3: AWS.S3 = new AWS.S3({
endpoint: MINIO_ENDPOINT,
accessKeyId: AWS_ACCESS_KEY_ID,
secretAccessKey: AWS_SECRET_ACCESS_KEY,
s3ForcePathStyle: true,
signatureVersion: 'v4',
});
private readonly uploadBucket: string = UPLOAD_BUCKET;
private readonly downloadBucket: string = DOWNLOAD_BUCKET;
public async upload(localPath: string, s3Key: string, onProgress: (progress: number) => void): Promise<void> {
await retry(async () => { // Be careful, it will influence stub.
const stat = fse.statSync(localPath);
let readable: stream.Readable;
let archive: archiver.Archiver | undefined;
if (stat.isFile()) {
readable = fse.createReadStream(localPath);
} else {
archive = archiver('zip', { zlib: { level: 0 } }).directory(localPath, false);
readable = archive;
}
const request = this.s3.upload({ Bucket: this.uploadBucket, Key: s3Key, Body: readable });
request.on('httpUploadProgress', ({ loaded }) => {
onProgress(loaded);
});
if (archive) {
archive.finalize().catch(console.error);
}
await request.promise().catch((err) => {
fse.removeSync(localPath);
throw err;
});
}, { max_tries: UPLOAD_RETRY_TIMES, throw_original: true });
}
}
export const storage = new Storage();
I try to stub this upload method in my unit test, it looks like:
import { storage } from './storage';
import * as AWS from 'aws-sdk';
import sinon from 'sinon';
describe('Storage', () => {
let sandbox: sinon.SinonSandbox;
before(() => {
sandbox = sinon.createSandbox();
});
afterEach(() => {
sandbox.restore();
});
it('upload', async () => {
const s3Stub = sandbox.stub(AWS.S3.prototype, 'upload'); // something wrong
await storage.upload(
'./package.json',
's3Key',
uploadBytes => { return uploadBytes; });
expect(s3Stub).to.have.callCount(1);
s3Stub.restore();
});
});
And I got an error:
Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
I want to test the upload method , but do not upload file to s3 really.
How should I do ?
Thank you everyone.
Enable esModuleInterop: true config in your tsconfig.json file and change the import * as AWS from 'aws-sdk' to import AWS from 'aws-sdk'.
Since the new Storage() statement will execute instantly when you import the this module, you should import the ./storage.ts module after you stub AWS.S3 class.
P.S. I deleted the code not related to the problem
E.g.
storage.ts:
import AWS from 'aws-sdk';
const UPLOAD_BUCKET = 'UPLOAD_BUCKET';
const MINIO_ENDPOINT = 'MINIO_ENDPOINT';
const AWS_ACCESS_KEY_ID = 'AWS_ACCESS_KEY_ID';
const AWS_SECRET_ACCESS_KEY = 'AWS_SECRET_ACCESS_KEY';
export class Storage {
private readonly s3: AWS.S3 = new AWS.S3({
endpoint: MINIO_ENDPOINT,
accessKeyId: AWS_ACCESS_KEY_ID,
secretAccessKey: AWS_SECRET_ACCESS_KEY,
s3ForcePathStyle: true,
signatureVersion: 'v4',
});
private readonly uploadBucket: string = UPLOAD_BUCKET;
public async upload(localPath: string, s3Key: string, onProgress: (progress: number) => void): Promise<void> {
const request = this.s3.upload({ Bucket: this.uploadBucket, Key: s3Key, Body: '123' });
}
}
export const storage = new Storage();
storage.test.ts:
import AWS from 'aws-sdk';
import sinon from 'sinon';
describe('68431461', () => {
let sandbox: sinon.SinonSandbox;
before(() => {
sandbox = sinon.createSandbox();
});
afterEach(() => {
sandbox.restore();
});
it('should pass', async () => {
const s3InstanceStub = { upload: sandbox.stub() };
const s3Stub = sandbox.stub(AWS, 'S3').callsFake(() => s3InstanceStub);
const { storage } = await import('./storage');
const onProgressStub = sandbox.stub();
await storage.upload('./package.json', 's3Key', onProgressStub);
sinon.assert.calledOnce(s3Stub);
sinon.assert.calledOnce(s3InstanceStub.upload);
});
});
test result:
68431461
✓ should pass (796ms)
1 passing (810ms)
------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
------------|---------|----------|---------|---------|-------------------
All files | 100 | 100 | 100 | 100 |
storage.ts | 100 | 100 | 100 | 100 |
------------|---------|----------|---------|---------|-------------------