axe-core/build/tasks/aria-supported.js

Accessibility engine for automated Web UI testing

/*eslint-env node */
'use strict';

const { roles, aria: props } = require('aria-query');
const mdTable = require('markdown-table');

module.exports = function (grunt) {
	grunt.registerMultiTask(
		'aria-supported',
		'Task for generating a diff of supported aria roles and properties.',
		function () {
			const entry = this.data.entry;
			const destFile = this.data.destFile;
			const listType = this.data.listType.toLowerCase();

			/**
			 * `axe` has to be dynamically required at this stage, as `axe` does not exist until grunt task `build:uglify` is complete, and hence cannot be required at the top of the file.
			 */
			const axe = require('../../axe');

			/**
			 * As `aria-query` roles map, does not list all aria attributes in its props,
			 * the below reduce function aims to concatanate and unique the below two, 
			 * - list from props with in roles map
			 * - list from aria map
			 * 
			 * @return {Map} `aQaria` - This gives a composite list of aria attributes, which is later used to diff against axe-core supported attributes.
			 */
			const ariaKeys = Array.from(props).map(([key]) => key)
			const roleAriaKeys = Array.from(roles)
				.reduce((out, [name, rule]) => {
					return [...out, ...Object.keys(rule.props)]
				}, []);
			const aQaria = new Set(axe.utils.uniqueArray(roleAriaKeys, ariaKeys));

			/**
			 * Given a `base` Map and `subject` Map object, 
			 * The function converts the `base` Map entries to an array which is sorted then enumerated to compare each entry against the `subject` Map 
			 * The function constructs a `string` to represent a `markdown table` to 
			 * @param {Map} base Base Map Object
			 * @param {Map} subject Subject Map Object
			 * @return {Array[]} Example Output: [ [ 'alert', 'No' ], [ 'figure', 'Yes' ] ]
			 */
			const getDiff = (base, subject) => {
				return Array.from(base.entries()).sort().reduce((out, [key] = item) => {
					switch (listType) {
						case 'supported':
							if (subject.includes(key)) {
								out.push([`${key}`, 'Yes']);
							}
							break;
						case 'unsupported':
							if (!subject.includes(key)) {
								out.push([`${key}`, 'No']);
							}
							break;
						case 'all':
						default:
							out.push([`${key}`, subject.includes(key) ? 'Yes' : 'No']);
							break;
					}
					return out;
				}, []);
			}

			const getMdContent = (heading, rolesTable, attributesTable) => {
				return `${heading}\n\n## Roles\n\n${rolesTable}\n\n## Attributes\n\n${attributesTable}`;
			}

			const generateDoc = () => {
				const content = getMdContent(
					`# ARIA Roles and Attributes ${listType === 'all' ? 'available' : listType} in axe-core.`,
					mdTable([['aria-role', 'axe-core support'], ...getDiff(roles, Object.keys(axe.commons.aria.lookupTable.role))]),
					mdTable([['aria-attribute', 'axe-core support'], ...getDiff(aQaria, Object.keys(axe.commons.aria.lookupTable.attributes))])
				);
				grunt.file.write(destFile, content)
			}

			generateDoc();
		}
	);
};