forked from babel/babel
/
index.js
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/
index.js
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// use if ie
// "es3-member-expression-literals",
// "es3-property-literals",
// "proto-to-assign",
// "es5-property-mutators",
import pluginList from "../data/plugins.json";
export const plugins = [
"es3-member-expression-literals",
"es3-property-literals",
"proto-to-assign",
"es5-property-mutators",
];
export const stagePlugins = [
// "transform-class-constructor-call", proposal is removed
"transform-class-properties",
"transform-transform-decorators-legacy", // legacy plugin
"transform-do-expressions",
"transform-export-extensions",
"transform-function-bind",
"transform-object-rest-spread",
];
export const MODULE_TRANSFORMATIONS = {
"amd": "transform-es2015-modules-amd",
"commonjs": "transform-es2015-modules-commonjs",
"systemjs": "transform-es2015-modules-systemjs",
"umd": "transform-es2015-modules-umd"
};
/**
* Determine if a transformation is required
* @param {Object} supportedEnvironments An Object containing environment keys and the lowest
* supported version as a value
* @param {Object} plugin An Object containing environment keys and the lowest
* version the feature was implmented in as a value
* @return {Boolean} Whether or not the transformation is required
*/
export const isPluginRequired = (supportedEnvironments, plugin) => {
const targetEnvironments = Object.keys(supportedEnvironments);
if (targetEnvironments.length === 0) { return true; }
const isRequiredForEnvironments = targetEnvironments
.filter(environemt => {
// Feature is not implemented in that environment
if (!plugin[environemt]) { return true; }
const lowestImplementedVersion = plugin[environemt];
const lowestTargetedVersion = targetEnvironments[environemt];
if (lowestTargetedVersion <= lowestImplementedVersion) { return true; }
return false;
});
return isRequiredForEnvironments.length > 0 ? true : false;
};
const getTargets = targetOpts => {
return targetOpts || {};
}
// TODO: Allow specifying plugins as either shortened or full name
// babel-plugin-transform-es2015-classes
// transform-es2015-classes
export const validateLooseOption = (looseOpt = false) => {
if (typeof looseOpt !== "boolean") {
throw new Error("Preset env: 'loose' option must be a boolean.");
}
return looseOpt;
}
export const validateModulesOption = (modulesOpt = "commonjs") => {
if (modulesOpt !== false && Object.keys(MODULE_TRANSFORMATIONS).indexOf(modulesOpt) === -1) {
throw new Error("The 'modules' option must be 'false' to indicate no modules\n" +
"or a module type which be be one of: 'commonjs' (default), 'amd', 'umd', 'systemjs'");
}
return modulesOpt;
}
export default function buildPreset(context, opts) {
const loose = validateLooseOption(opts.loose);
const moduleType = validateModulesOption(opts.modules);
const targets = getTargets(opts.targets);
const transformations = Object.keys(pluginList)
.filter(pluginName => isPluginRequired(targets, pluginList[pluginName]))
.map(pluginName => {
return [require(`babel-plugin-${pluginName}`), { loose }]
});
const modules = [
moduleType === "commonjs" && [require("babel-plugin-transform-es2015-modules-commonjs"), { loose }],
moduleType === "systemjs" && [require("babel-plugin-transform-es2015-modules-systemjs"), { loose }],
moduleType === "amd" && [require("babel-plugin-transform-es2015-modules-amd"), { loose }],
moduleType === "umd" && [require("babel-plugin-transform-es2015-modules-umd"), { loose }],
].filter(Boolean);
return {
plugins: [
...modules,
...transformations
]
}
}