Author: John Au-Yeung

To unit test routes with Express and JavaScript, we use supertest.

For instance, we write

describe("GET /users", () => {
  it("respond with json", (done) => {
    request(app)
      .get("/users")
      .set("Accept", "application/json")
      .expect(200)
      .end((err, res) => {
        if (err) return done(err);
        done();
      });
  });
});

to call request with app to use the Express app to make requests.

Then we call get to make a get request to the /users route.

We call set to set the request header.

We call expect to check that the status code returned is 200.

And we call end with a callback that calls done to finish the test.

The test passes if done is called with no argument.

To add dates to pm2 error logs with JavaScript, we add the --lof-date-format option.

For instance, we run

pm2 start app.js --log-date-format 'DD-MM HH:mm:ss.SSS'

to set the --log-date-format to the date format we want for the log entry date to include the date in each log entry.

To fix npm – "Can’t find Python executable "python", you can set the PYTHON env variable." error with JavaScript, we install the window-build-tools package.

To fix this, we run

npm install -g windows-build-tools

to install the window-build-tools package globally which includes Python.

To fix the /usr/bin/env: node: No such file or directory error with Node forever, we clear the npm cache.

We run

sudo npm cache clean -f
sudo npm install -g n
sudo n stable

to force clear the NPM cache with

sudo npm cache clean -f

Then we install the latest version of n with

sudo npm install -g n

We run the latest stablke version with

n stable

To protect the password field in Mongoose/MongoDB so it won’t return in a query when populating collections with JavaScript, we set the select option to false.

For instance, we write

const userSchema = new Schema({
  name: { type: String, required: false, minlength: 5 },
  email: { type: String, required: true, minlength: 5 },
  phone: String,
  password: { type: String, select: false },
});

to create a schema with the password field having the select option set to false.

Then the field’s value won’t be returned when we query the userSchema.