npm:mocha-when | Skypack

README

“What's this?”

This is a drop-in enhancement for Mocha's BDD interface, which adds two small but tangible improvements:

A `when()` global

This is the same calling describe(), but the description you give is automatically prefixed by "When ":

when("this test is run", () => {
    it('gets prepended with the word "When"', …);
});

Which is a shorter, clearer way of writing:

describe("when this test is run", () => …);

Tests specified by `it()` actually start with `"It "`

Mocha makes idiomatic tests fun to write ...

describe("when the app starts", () => {
    it("activates successfully", () => …);
    it("connects to the server", () => …);
    it("receives a valid payload", () => …);
});

... but not as fun to read:

when the app starts
  ✓ activates successfully
  ✓ connects to the server
  ✓ receives a valid payload
  ✓ displays the result

This module fixes such broken language by automatically prefixing each test:

when the app starts
  ✓ it activates successfully
  ✓ it connects to the server
  ✓ it receives a valid payload
  ✓ it displays the result

If a test (or suite) description already includes the expected prefix, it won't be modified. So you needn't worry about stuff like this:

when When the prefix is included
  ✓ it it won't repeat the word "it"
  ✓ it it'll check for contractions too

Usage

Add mocha-when to your project's dependencies:

# Using NPM:
npm install --save-dev mocha-when

# Or with Yarn:
yarn add mocha-when

Activate it by calling the function it exports:

require("mocha-when")();

Or simply pass mocha-when/register to Mocha's require option:

// In your `.mocharc.js` file:
module.exports = {
    require: [
        "mocha-when/register",
    ]
};

Caveats

ESLint won't recognise the when() global, so add it to your globals list.
Mocha's ui option is assumed to be bdd (the default).
Tests can be declared without an it prefix using specify().
The enhancements applied by this module are persistent and irrevocable.

Usage no npm install needed!