read-modify-write/test/runner.js

Node module for reading, modifying and writing files recursively

// `tests` is a singleton variable that will contain all our tests
const tests = [];
const path = require('path');

// The test function accepts a name and a function
function test(name, fn) {
	// it pushes the name and function as an object to
	// the `tests` array
	tests.push({ name, fn })
}

function run() {
	// `run` runs all the tests in the `tests` array
	tests.forEach(t => {
		// For each test, we try to execute the
		// provided function. 
		try {
			const output = t.fn();
			if(output instanceof Promise) {
				return output
					.then(() => console.log('OK    ', t.name))
					.catch((e) => {
						// Exceptions, if any, are caught
						// and the test is considered failed
						console.log('FAIL  ', t.name)
						// log the stack of the error
						console.log(e.stack)
					}); // Error: Whoops!
			}
			// If there is no exception
			// that means it ran correctly
			console.log('OK    ', t.name)
		} catch (e) {
			// Exceptions, if any, are caught
			// and the test is considered failed
			console.log('FAIL  ', t.name)
			// log the stack of the error
			console.log(e.stack)
		}
	})
}

// Get the list of files from the command line
// arguments
const files = process.argv.slice(2)

// expose the test function as a global variable
global.test = test;

// Load each file using `require`
files.forEach(file => {
	// Once a file is loaded, it's tests are
    // added to the `tests` singleton variable
	require(path.join(__dirname, file))
})

// Now that all the tests from all the files are
// added, run them one after the other
run();