triple-a
v1.0.0
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The Arrange-Act-Assert testing library to help keep tests focused
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Triple-A
Structured testing for better communication
Table Of Contents
What is it?
Triple-A is a testing tool designed to help you structure your tests in a sensible way. It is directly based on the "AAA" or Arrange/Act/Assert testing approach, and carries a philosophy:
- Only test one thing at a time
- Order of test implementation facilitates communication
- More, descriptive tests is better
- Isolated tests are best
Triple-A is opinionated because that's what it's for.
Installation
Prerequisites
In order to use Triple-A you will need:
- to have Node.js installed on your computer
- a working understanding of how to use npm
- to have a testing framework installed in your project
Installing Triple-A
Triple-A is a testing framework, intended for development use. Don't deploy it to production.
Install it as a development dependency this way:
npm install triple-a --save-dev
How Do I Use It?
Triple-A works through chaining together the arrange, act, and assert segments of your test. Every step stands alone, and supports asynchronous behavior out of the box. Run it and go.
Here's a single test for FizzBuzz:
const tripleA = require('triple-a');
it('returns FizzBuzz when called with 15', () => {
return tripleA
.arrange(() => {
const testValue = 15;
return testValue;
})
.act((testValue) => {
return fizzBuzz(testValue);
})
.assert(({ result }, { assertEqual }) => {
const expectedValue = 'FizzBuzz';
assertEqual(result, expectedValue);
})
});
For promise-returning async tests, follow the same form. Make sure to return the Triple-A output as it provides a promise to the test system. This uniformity makes tests easier to read and understand.
In the end, test code is organized into self-managing buckets. This means it is easier to parse the code when read. Also, when the tests run, the code is fully isolated. This isolation makes it safe, even when tests are parallelized.