MDL-66265 javascript: Add basic jshint ignores
[moodle.git] / babel-plugin-add-module-to-define.js
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1// This file is part of Moodle - http://moodle.org/
2//
3// Moodle is free software: you can redistribute it and/or modify
4// it under the terms of the GNU General Public License as published by
5// the Free Software Foundation, either version 3 of the License, or
6// (at your option) any later version.
7//
8// Moodle is distributed in the hope that it will be useful,
9// but WITHOUT ANY WARRANTY; without even the implied warranty of
10// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11// GNU General Public License for more details.
12//
13// You should have received a copy of the GNU General Public License
14// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
15
16/**
17 * This is a babel plugin to add the Moodle module names to the AMD modules
18 * as part of the transpiling process.
19 *
20 * In addition it will also add a return statement for the default export if the
21 * module is using default exports. This is a highly specific Moodle thing because
22 * we're transpiling to AMD and none of the existing Babel 7 plugins work correctly.
23 *
24 * This will fix the issue where an ES6 module using "export default Foo" will be
25 * transpiled into an AMD module that returns {default: Foo}; Instead it will now
26 * just simply return Foo.
27 *
28 * Note: This means all other named exports in that module are ignored and won't be
29 * exported.
30 *
31 * @copyright 2018 Ryan Wyllie <ryan@moodle.com>
32 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
33 */
34
35"use strict";
36
37module.exports = ({ template, types }) => {
38 const fs = require('fs');
ac1a91bf 39 const path = require('path');
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40 const glob = require('glob');
41 const cwd = process.cwd();
42
43 // Static variable to hold the modules.
44 let moodleSubsystems = null;
45 let moodlePlugins = null;
46
47 /**
48 * Parse Moodle's JSON files containing the lists of components.
49 *
50 * The values are stored in the static variables because we
51 * only need to load them once per transpiling run.
52 */
53 function loadMoodleModules() {
54 moodleSubsystems = {'lib': 'core'};
55 moodlePlugins = {};
56 let components = fs.readFileSync('lib/components.json');
57 components = JSON.parse(components);
58
59 for (const [component, path] of Object.entries(components.subsystems)) {
60 if (path) {
61 // Prefix "core_" to the front of the subsystems.
62 moodleSubsystems[path] = `core_${component}`;
63 }
64 }
65
66 for (const [component, path] of Object.entries(components.plugintypes)) {
67 if (path) {
68 moodlePlugins[path] = component;
69 }
70 }
71
72 for (const file of glob.sync('**/db/subplugins.json')) {
73 var rawContents = fs.readFileSync(file);
74 var subplugins = JSON.parse(rawContents);
75
2c28ba88 76 for (const [component, path] of Object.entries(subplugins.plugintypes)) {
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77 if (path) {
78 moodlePlugins[path] = component;
79 }
80 }
81 }
82 }
83
84 /**
85 * Search the list of components that match the given file name
86 * and return the Moodle component for that file, if found.
87 *
88 * Throw an exception if no matching component is found.
89 *
90 * @throws {Error}
91 * @param {string} searchFileName The file name to look for.
92 * @return {string} Moodle component
93 */
94 function getModuleNameFromFileName(searchFileName) {
95 searchFileName = fs.realpathSync(searchFileName);
ac1a91bf 96 const relativeFileName = searchFileName.replace(`${cwd}${path.sep}`, '').replace(/\\/g, '/');
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97 const [componentPath, file] = relativeFileName.split('/amd/src/');
98 const fileName = file.replace('.js', '');
99
100 // Check subsystems first which require an exact match.
101 if (moodleSubsystems.hasOwnProperty(componentPath)) {
102 return `${moodleSubsystems[componentPath]}/${fileName}`;
103 }
104
105 // It's not a subsystem so it must be a plugin. Moodle defines root folders
106 // where plugins can be installed so our path with be <plugin_root>/<plugin_name>.
107 // Let's separate the two.
108 let pathParts = componentPath.split('/');
109 const pluginName = pathParts.pop();
110 const pluginPath = pathParts.join('/');
111
112 // The plugin path mutch match exactly because some plugins are subplugins of
113 // other plugins which means their paths would partially match.
114 if (moodlePlugins.hasOwnProperty(pluginPath)) {
115 return `${moodlePlugins[pluginPath]}_${pluginName}/${fileName}`;
116 }
117
118 // This matches the previous PHP behaviour that would throw an exception
119 // if it couldn't parse an AMD file.
120 throw new Error('Unable to find module name for ' + searchFileName);
121 }
122
123 // This is heavily inspired by the babel-plugin-add-module-exports plugin.
124 // See: https://github.com/59naga/babel-plugin-add-module-exports
125 //
126 // This is used when we detect a module using "export default Foo;" to make
127 // sure the transpiled code just returns Foo directly rather than an object
128 // with the default property (i.e. {default: Foo}).
129 //
130 // Note: This means that we can't support modules that combine named exports
131 // with a default export.
132 function addModuleExportsDefaults(path, exportObjectName) {
133 const rootPath = path.findParent(path => {
134 return path.key === 'body' || !path.parentPath;
135 });
136
137 // HACK: `path.node.body.push` instead of path.pushContainer(due doesn't work in Plugin.post).
138 // This is hardcoded to work specifically with AMD.
139 rootPath.node.body.push(template(`return ${exportObjectName}.default`)())
140 }
141
142 return {
143 pre() {
144 this.seenDefine = false;
145 this.addedReturnForDefaultExport = false;
146
147 if (moodleSubsystems === null) {
148 loadMoodleModules();
149 }
150 },
151 visitor: {
152 // Plugin ordering is only respected if we visit the "Program" node.
153 // See: https://babeljs.io/docs/en/plugins.html#plugin-preset-ordering
154 //
155 // We require this to run after the other AMD module transformation so
156 // let's visit the "Program" node.
157 Program: {
158 exit(path) {
159 path.traverse({
160 CallExpression(path) {
161 // If we find a "define" function call.
162 if (!this.seenDefine && path.get('callee').isIdentifier({name: 'define'})) {
163 // We only want to modify the first instance of define that we find.
164 this.seenDefine = true;
165 // Get the Moodle component for the file being processed.
166 var moduleName = getModuleNameFromFileName(this.file.opts.filename);
167 // Add the module name as the first argument to the define function.
168 path.node.arguments.unshift(types.stringLiteral(moduleName));
169 // Add a space after the define function in the built file so that previous versions
170 // of Moodle will not try to add the module name to the file when it's being served
171 // by PHP. This forces the regex in PHP to not match for this file.
172 path.node.callee.name = 'define ';
173 }
174
175 // Check for any Object.defineProperty('exports', 'default') calls.
176 if (!this.addedReturnForDefaultExport && path.get('callee').matchesPattern('Object.defineProperty')) {
177 const [identifier, prop] = path.get('arguments')
178 const objectName = identifier.get('name').node
179 const propertyName = prop.get('value').node
180
181 if ((objectName === 'exports' || objectName === '_exports') && propertyName === 'default') {
182 addModuleExportsDefaults(path, objectName);
183 this.addedReturnForDefaultExport = true;
184 }
185 }
186 },
187 AssignmentExpression(path) {
188 // Check for an exports.default assignments.
189 if (
190 !this.addedReturnForDefaultExport &&
191 (
192 path.get('left').matchesPattern('exports.default') ||
193 path.get('left').matchesPattern('_exports.default')
194 )
195 ) {
196 const objectName = path.get('left.object.name').node;
197 addModuleExportsDefaults(path, objectName);
198 this.addedReturnForDefaultExport = true;
199 }
200 }
201 }, this);
202 }
203 }
204 }
205 };
2c28ba88 206};