TestFile.js

'use strict';
/**
 * Event Emitter of Node.JS
 *
 * @external EventEmitter
 *
 * @see {@link https://nodejs.org/dist/latest-v4.x/docs/api/events.html#events_class_eventemitter}
 */
const EventEmitter = require('events'),
      Path = require('path'),
      Beautify = require('js-beautify');


/**
 * **Test script** class
 *
 * @extends external:EventEmitter
 */
class TestScript extends EventEmitter {
    /**
     * @author TechQuery <shiy007@qq.com>
     *
     * @param {string} URI        - Path of a **Source module**
     * @param {string} sourcePath - Path of the **Source directory**
     * @param {string} testPath   - Path of the **Test directory**
     */
    constructor(URI, sourcePath, testPath) {

        super().length = 0;

        this.sourcePath = Path.join(process.cwd(), sourcePath);

        this.testPath = Path.join(process.cwd(), testPath);

        this.URI = (
            Path.isAbsolute( URI )  ?
                Path.relative(this.sourcePath, URI)  :  URI
        ).replace(/\\/g, '/');

        this.testURI = Path.join(this.testPath, this.URI);

        this.sourceURI = Path.relative(
            this.testURI,  Path.join(this.sourcePath, this.URI)
        ).replace(/\\/g, '/');

        this.ID = TestScript.toBigCamel( Path.basename(URI, '.js') );

        this.header = [ ];
    }

    static toBigCamel(raw) {

        return  raw.replace(/^\w|[_\-](\w)/g,  function (A, B) {

            return  (B || A).toUpperCase();
        });
    }

    addHeader(raw) {

        if (raw  &&  (this.header.indexOf( raw )  <  0))
            this.header.push( raw );
    }

    /**
     * Add Test unit
     *
     * @author TechQuery
     * @since  0.2.0
     *
     * @param {object} Doclet
     *
     * @throws {SyntaxError} While the `title`, `script` or `expected` of
     *                       an Example is missing
     */
    addUnit(Doclet) {

        if (! (Doclet.examples instanceof Array))  return;

        var case_key = ['title', 'script', 'expected'];

        this[ this.length++ ] = {
            title:    Doclet.longname,
            item:     Doclet.examples.map(function (item) {

                item = item.match(
                    /^\/\/\s*(.+?)(?:\r|\n|\r\n){2,}([\s\S]+)\s+\/\/([\s\S]+)/
                )  ||  [ ];
                /**
                 * **Test item** object
                 *
                 * @typedef {object} TestItem
                 *
                 * @property {string} title       - **Comment text** in the
                 *                                  same line of `@example`
                 * @property {string} script      - **Source code** to be tested
                 * @property {string} expected    - Expected result
                 * @property {string} [source=''] - Full source code of
                 *                                  this test
                 */
                var test_case = {source: ''};

                for (let i = 0;  case_key[i];  i++)
                    if (! (
                        test_case[ case_key[i] ] = (item[i + 1] || '').trim()
                            .replace(/\r\n|\r/g, "\n")
                    ))
                        throw SyntaxError(
                            `The ${case_key[i]} of ${Doclet.longname} is missing`
                        );

                return  test_case;
            })
        };
    }

    getHeader() {
        /**
         * **Test header** object
         *
         * @typedef {object} TestHeader
         *
         * @property {string} URI         - Module URI relative to
         *                                  the **Source directory**
         * @property {string} sourceURI   - Module URI relative to
         *                                  this **Test scirpt**
         * @property {string} [source=''] - The header's source code of
         *                                  this **Test script**
         */
        var header = {
                URI:          this.URI,
                sourceURI:    this.sourceURI,
                source:       ''
            };
        /**
         * Before the **Test script** writed
         *
         * @event TestScript#fileWrite
         */
        this.emit('fileWrite', header);

        if ( header.source )  this.addHeader( header.source );

        /**
         * Before the header of **Test script** writed
         *
         * @event TestScript#headerWrite
         */
        header.source = '';

        this.emit('headerWrite', header);

        return header.source;
    }

    /**
     * @author TechQuery <shiy007@qq.com>
     * @since  0.2.0
     *
     * @return {string} Source code of this **Test script**
     */
    toString() {

        var _this_ = this, header = this.getHeader();

        return  Beautify(`'use strict';

            require('should');

            ${this.header.join("\n\n")}

            describe('${this.URI}',  function () {

                ${header}

            ${Array.from(this,  function (test) {

                return `describe('${test.title}',  function () {

                    ${test.item.map(function (item) {
                        /**
                         * Before **Test item** writed
                         *
                         * @event TestScript#itemWrite
                         */
                        _this_.emit('itemWrite', item);

                        return  item.source || `it('${item.title}',  function () {

                            var result = ${item.script};

                            result.should.be.deepEqual( ${item.expected} );
                        });`;
                    }).join('')}
                    });
                `;
            }).join("\n")}
            });`
        );
    }
}


/**
 * @callback fileWrite
 *
 * @param {TestHeader} header
 *
 * @example  // TestHook.js
 *
 *     exports.fileWrite = function (header) {
 *
 *         header.source = 'custom test script';
 *     };
 */

/**
 * @callback headerWrite
 *
 * @param {TestHeader} header
 *
 * @example  // TestHook.js
 *
 *     exports.headerWrite = function (header) {
 *
 *         header.source = 'custom test script';
 *     };
 */

/**
 * @callback itemWrite
 *
 * @param {TestItem} item
 *
 * @example  // TestHook.js
 *
 *     exports.itemWrite = function (item) {
 *
 *         item.source = 'custom test script';
 *     };
 */


module.exports = TestScript;