How to use nock to intercept requests regardless of body

Question

I'm trying to use nock in my tests to intercept the request calls i'm making from the native https module in Node.js. I'm using Promise.all to make two requests to the external server. I want my tests to intercept the calls, and check some of the form fields to make sure they're filled in as i want.

I have my class setup below (kept the most relevant parts of code in):

const archiver = require('archiver');
const { generateKeyPairSync } = require('crypto');
const FormData = require('form-data');
const fs = require('fs');
const https = require('https');

class Platform {
  constructor() {
    this.FILESTORE_USERNAME = process.env.FILESTORE_USERNAME;
    this.FILESTORE_PASSWORD = process.env.FILESTORE_PASSWORD;
  }

  store(serviceName) {
    const { publicKey, privateKey } = this._generateKeys();

    return Promise.all([this._postKey(publicKey), this._postKey(privateKey)])
      .then(() => {
        return this._zipKeys(publicKey, privateKey, serviceName);
      })
      .catch((err) => {
        throw err;
      });
  }

  _postKey(key) {
    const options = this._getOptions();
    const keyName = (key.search(/(PUBLIC)/) !== -1) ? 'publicKey' : 'privateKey';
    const form = new FormData();
    form.append('file', key);
    form.append('Name', keyName);
    form.append('MimeMajor', 'application');
    form.append('MimeMinor', 'x-pem-file');
    form.append('Extension', (keyName == 'publicKey') ? 'pub' : '');
    form.append('FileClass', 'MFS::File');
    options.headers = form.getHeaders();
    options.headers.Authorization = 'Basic ' + Buffer.from(this.FILESTORE_USERNAME + ':' + this.FILESTORE_PASSWORD).toString('base64');

    return new Promise((resolve, reject) => {
      let post = https.request(options, (res) => {
        let data = '';
        if (res.statusCode < 200 || res.statusCode > 299) {
          reject(new Error('File Storage API returned a status code outside of acceptable range: ' + res.statusCode));
        } else {
          res.setEncoding('utf8');
          res.on('data', (chunk) => {
            data += chunk;
          });

          res.on('error', (err) => {
            reject(err);
          });

          res.on('end', () => {
            if (data) {
              resolve(JSON.parse(data));
            } else {
              resolve();
            }
          });
        }
      });
      post.on('error', (err) => {
        reject(err);
      });
      form.pipe(post);
      post.end();

    });
  }

  _getOptions() {
    return {
      hostname: 'api.example.com',
      path: '/media/files/',
      method: 'POST',
    };
  }
}

module.exports = Platform;

And then, my testing code looks like the below. I'm using mocha, sinon, chai, sinon-chai and nock.

const Platform = require('/usr/src/app/api/Services/Platform');
const crypto = require('crypto');
const fs = require('fs');
const nock = require('nock');
const yauzl = require('yauzl');

describe('Platform', function() {
  let platform;
  beforeEach(() => {
    platform = new Platform();
  });
  afterEach(() => {
    const list = fs.readdirSync('/usr/src/app/api/Services/data/');
    list.forEach((file) => {
      fs.unlink('/usr/src/app/api/Services/data/' + file, (err) => {
        if (err) throw err;
      });
    });
    nock.cleanAll();
  });
  after(() => {
    nock.restore();
  });
  describe('store', function() {
    it('should post each generated key to an external storage place', async function() {
      this.timeout(5000);
      // const stub = sinon.stub(platform, '_postKey').resolves();
      const scope = nock('https://api.example.com')
        .persist()
        .post('/media/files/', (body) => {
          // console.log(body);
        })
        .reply(200);

      let serviceName = 'test';
      let actual = await platform.store(serviceName)
        .catch((err) => {
          (() => { throw err; }).should.not.throw();
        });

      console.log(scope);
      // expect(stub.callCount).to.equal(2);
      expect(actual).to.be.a('string');
      expect(actual).to.include(serviceName + '.zip');
      // stub.reset();

    });
  });
});

The problem I am coming across is this error that is thrown when running my tests:

AssertionError: expected [Function] to not throw an error but 'Error: Nock: No match for request {\n "method": "POST",\n "url": "https://api.example.com/media/files/",\n "headers": {\n
"content-type": "multipart/form-data; boundary=--------------------------363749230271182821931703",\n
"authorization": "Basic abcdef1224u38454857483hfjdhjgtuyrwyt="\n },\n "body": "----------------------------363749230271182821931703\r\nContent-Disposition: form-data; name=\"file\"\r\n\r\n-----BEGIN PUBLIC KEY-----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\nDWXpfMJUU8TQuLGWZQaGJc8CAwEAAQ==\n-----END PUBLIC KEY-----\n\r\n----------------------------363749230271182821931703\r\nContent-Disposition: form-data; name=\"Name\"\r\n\r\npublicKey\r\n----------------------------363749230271182821931703\r\nContent-Disposition: form-data; name=\"MimeMajor\"\r\n\r\napplication\r\n----------------------------363749230271182821931703\r\nContent-Disposition: form-data; name=\"MimeMinor\"\r\n\r\nx-pem-file\r\n----------------------------363749230271182821931703\r\nContent-Disposition: form-data; name=\"Extension\"\r\n\r\npub\r\n----------------------------363749230271182821931703\r\nContent-Disposition: form-data; name=\"FileClass\"\r\n\r\nMFS::File\r\n----------------------------363749230271182821931703--\r\n"\n}' was thrown

I take it it's because nock expects me to fake out the body for the request to get a correct match? Is there a way of just looking for requests made to that address, regardless of the body, so I can do my own tests or whatever.

Answer 1

When the post method of a Nock Scope is passed a second argument, it is used to match against the body of the request.

Docs for specifying the request body

In your test, you're passing a function as the second argument, but not returning true so Nock is not considering it a match.

From the docs:

Function: nock will evaluate the function providing the request body object as first argument. Return true if it should be considered a match

Since your goal is to assert form fields on the request, your best approach would be to leave the function there, do your assertions where the // console.log(body); line is, but add return true; to the end of the function.

You could also return true or false depending on if your form fields match your assertions, but in my experience it makes the error output from the test convoluted. My preference is to use standard chai expect() calls and let the assertions bubble errors before Nock continues with request matching.