string#test ~ drive tests in javascript from strings as descriptors

string-test.js

// Idea: August 10, 14, 2014

// Implementation: February 2, 2021

// Embrace patching of prototypes, and de-clutter the global scope, to 
// allow tests be driven by strings.

String.prototype.test = function(fn) {
  var test = this

  var assert = function(condition, msg) {
    var status = condition ? "Pass" : "Fail"
    
    var report = [status, ": ", test.valueOf(), " > ", condition]
    var method = "log"
    
    if (!condition) {
      report.push(msg ? " ("+msg+")" : "")
      method = "error"
    }
    
    console[method](report.join("").toString())
  }

  fn.call(test, assert)
}

// one assert per test
'should be two'.test(function(assert) {
  
  var a = 1;
  assert(2 * a === 2, "should equal 2");
  
  'should run nested tests like a suite'.test(function(assert) {

    var b = 2;
    assert(typeof b == 'string', "b ain't no string")
    
    // et cetera
  });
});

/* Test output */

// Pass: should be two > true
// Fail: should run nested tests like a suite > false (b ain't no string)