Chris Stead cmstead

cmstead / memoized-lazy-id.js

Created October 11, 2017 06:45

Lazy ID with memoization

	const nullFn = (fn) => typeof fn === 'function' ? fn : () => null;

	function dict(key, value, struct) {
	return (function (localStruct) {
	return (ref) => ref === key ? value : localStruct(ref)
	})(nullFn(struct));
	}

	function memoize(fn) {
	let store = null;

cmstead / multiply-then-divide-composition.js

Created October 1, 2017 20:46

MultiplyThenDivide composition

	const multiply = (a, b) => a * b;
	const divide = (a, b) => a / b;

	const multiplyThenDivide = (a, b, c) => divide(multiply(a, b), c);

cmstead / quickspec-multiplyThenDivide.js

Last active October 1, 2017 19:56

Example of testing composition of multiply and divide with Quickspec

	describe('runMultiplyThenDivide', function() {

	it('should properly evaluate the composition of multiply and divide', function () {
	const specSet = [
	{
	name: 'Zero-multiplication',
	setupValues: { a: 0, b: 1, c: 2 },
	expectedValue: 0
	},
	{

cmstead / Tests for multiplyThenDivide

Last active October 1, 2017 19:53

Example of testing composite multiplyThenDivide, many cases

	describe('multiplyThenDivide', function() {

	it('should return 0 when multiplying by 0, dividing by 2', function() {
	assert.equal(multiplyThenDivide(0, 1, 2), 0);
	});

	it('should return half of value when multiplying by 5, dividing by 2', function() {
	assert.equal(multiplyThenDivide(1, 5, 2), 2.5);
	});

cmstead / testSnippets.json

Last active May 3, 2017 16:03

My test snippets for VS Code

cmstead / extended-simple-ui-test-runner.js

Last active February 7, 2017 06:48

Extended test runner for UI tests

	(function (testRunner) {
	'use strict';

	function logAndTestUi(sample, expectedMean, expectedStandardDeviation) {
	var message = 'Testing -- ' +
	'sample: ' + JSON.stringify(sample) + '; ' +
	'expected mean: ' + expectedMean + '; ' +
	'expected standard deviation: ' + expectedStandardDeviation;

	console.log(message);

cmstead / simple-ui-test-runner.js

Last active February 7, 2017 06:45

Simple UI test runner for stats example program

	var testRunner = (function () {
	'use strict';

	function isMatch (expectedValue, actualValue) {
	var equalMatch = expectedValue === actualValue;
	var NaNMatch = Number.isNaN(expectedValue) && Number.isNaN(actualValue);

	return equalMatch \|\| NaNMatch;
	}

cmstead / stats-computer.html

Last active February 7, 2017 06:47

User view for simple stats API example

	<html>

	<body>
	<input type="text" value="" name="sample" id="sample" />
	<button id="compute">Compute Mean and Standard Deviation</button>

	<h4>Mean:</h4>
	<p id="mean">0</p>

	<h4>Standard Deviation:</h4>

cmstead / view-helper.js

Created February 5, 2017 21:12

Simple helper for Stats API example code

	var viewHelper = (function () {
	'use strict';

	function parseNumberValues (valueStr) {
	return valueStr.trim().split(/[\s\,]+/).map(parseFloat);
	}

	return {
	parseNumberValues: parseNumberValues
	};

cmstead / stats-api.js

Created February 5, 2017 21:11

Simple stats API example

	var statsApi = (function () {
	'use strict';

	var square = pow(2);
	var squareRoot = pow(0.5);

	function getStandardDeviation (values) {
	var xBar = getMean(values);
	var computedValues = values.map(subtractMeanAndSquare(xBar));
	return squareRoot(getMean(computedValues));