cxelegance / utestfn

quick unit test for vanilla JavaScript

uTest

quick unit test for vanilla JavaScript

Is this for you?

Most likely you should be using a mainstream unit testing library/package for JavaScript; I personally didn't have time to research and choose one – I just quickly made this.

Is it better to quickly reinvent a wheel?

As mentioned, I didn't have time to look at the other wheels, and this here was very quick to make. What was great for me is that I could define a function, then tack on some test inputs and some expected test outputs, then essentially say "run" and have it report any failures. I could enter the test cases in the same file as the function I was developing, which I found convenient.

How does it work?

First, have a function to test; e.g:

function gcd (num1, num2){
   // if you want uTestFn to control debugging info
   var isDebug = this && this.isDebug;
   
   if(isDebug) console.log('you want the gcd of '+num1+' and '+num2+'?');
   
   // let's fail on a specific case
   if(num1 == 3 && num2 == 4) return 4; // wrong!
   else return goodTestedGCD(3, 4);
}

Then ask uTest to prepare to test your function:

uTestFn(gcd);

Then push some test inputs and expected outputs:

gcd.uTestInputs.push([2, 4]);
gcd.uTestOutputs.push(2);

gcd.uTestInputs.push([3, 4]);
gcd.uTestOutputs.push(1);

gcd.uTestInputs.push([7, 14]);
gcd.uTestOutputs.push(7);

Then run the test:

if(!gcd.uTest()) throw 'gcd() failed at least one test!';

If one of your test cases failed, execution will stop on the thrown exception; you can then:

gcd.uTest(null, true);

You will see a list (in console) of all tests and their pass/fail status.

test 0; pass; params: [2,1]; output: 2; expected: "04" uTestFn.js:61:31
test 1; FAIL; params: [3,4]; output: 4; expected: 1 uTestFn.js:61:31
test 2; pass; params: [7,14]; output: 7; expected: 7 uTestFn.js:61:31
false

You can then dig into the failed test:

gct.uTest(2, true, true);

The final parameter "true" will ensure that any debugging output is shown.