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Diffstat (limited to 'lib/esm.js')
| -rw-r--r-- | lib/esm.js | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/lib/esm.js b/lib/esm.js new file mode 100644 index 000000000..84ac0f353 --- /dev/null +++ b/lib/esm.js @@ -0,0 +1,161 @@ +/* + * Extension to detect ES6 and auto-load Traceur or Babel for processing + */ +(function() { + // good enough ES6 module detection regex - format detections not designed to be accurate, but to handle the 99% use case + var esmRegEx = /(^\s*|[}\);\n]\s*)(import\s*(['"]|(\*\s+as\s+)?[^"'\(\)\n;]+\s*from\s*['"]|\{)|export\s+\*\s+from\s+["']|export\s*(\{|default|function|class|var|const|let|async\s+function))/; + + var traceurRuntimeRegEx = /\$traceurRuntime\s*\./; + var babelHelpersRegEx = /babelHelpers\s*\./; + + hook('translate', function(translate) { + return function(load) { + var loader = this; + var args = arguments; + return translate.apply(loader, args) + .then(function(source) { + // detect & transpile ES6 + if (load.metadata.format == 'esm' || load.metadata.format == 'es6' || !load.metadata.format && source.match(esmRegEx)) { + if (load.metadata.format == 'es6') + warn.call(loader, 'Module ' + load.name + ' has metadata setting its format to "es6", which is deprecated.\nThis should be updated to "esm".'); + + load.metadata.format = 'esm'; + + if (load.metadata.deps) { + var depInject = ''; + for (var i = 0; i < load.metadata.deps.length; i++) + depInject += 'import "' + load.metadata.deps[i] + '"; '; + load.source = depInject + source; + } + + if (loader.transpiler === false) { + // we accept translation to esm for builds though to enable eg rollup optimizations + if (loader.builder) + return source; + throw new TypeError('Unable to dynamically transpile ES module as SystemJS.transpiler set to false.'); + } + + // setting _loader.loadedTranspiler = false tells the next block to + // do checks for setting transpiler metadata + loader._loader.loadedTranspiler = loader._loader.loadedTranspiler || false; + if (loader.pluginLoader) + loader.pluginLoader._loader.loadedTranspiler = loader._loader.loadedTranspiler || false; + + // do transpilation + return (loader._loader.transpilerPromise || ( + loader._loader.transpilerPromise = Promise.resolve( + __global[loader.transpiler == 'typescript' ? 'ts' : loader.transpiler] || (loader.pluginLoader || loader).normalize(loader.transpiler) + .then(function(normalized) { + loader._loader.transpilerNormalized = normalized; + return (loader.pluginLoader || loader).load(normalized) + .then(function() { + return (loader.pluginLoader || loader).get(normalized); + }); + }) + ))).then(function(transpiler) { + loader._loader.loadedTranspilerRuntime = true; + + // translate hooks means this is a transpiler plugin instead of a raw implementation + if (transpiler.translate) { + // if transpiler is the same as the plugin loader, then don't run twice + if (transpiler == load.metadata.loaderModule) + return load.source; + load.metadata.loaderModule = transpiler; + load.metadata.loader = loader._loader.transpilerNormalized; + + // convert the source map into an object for transpilation chaining + if (typeof load.metadata.sourceMap == 'string') + load.metadata.sourceMap = JSON.parse(load.metadata.sourceMap); + + return Promise.resolve(transpiler.translate.apply(loader, args)) + .then(function(source) { + // sanitize sourceMap if an object not a JSON string + var sourceMap = load.metadata.sourceMap; + if (sourceMap && typeof sourceMap == 'object') { + var originalName = load.address.split('!')[0]; + + // force set the filename of the original file + if (!sourceMap.file || sourceMap.file == load.address) + sourceMap.file = originalName + '!transpiled'; + + // force set the sources list if only one source + if (!sourceMap.sources || sourceMap.sources.length <= 1 && (!sourceMap.sources[0] || sourceMap.sources[0] == load.address)) + sourceMap.sources = [originalName]; + } + + if (load.metadata.format == 'esm' && !loader.builder && detectRegisterFormat(source)) + load.metadata.format = 'register'; + return source; + }); + } + + // legacy builder support + if (loader.builder) + load.metadata.originalSource = load.source; + + // defined in es6-module-loader/src/transpile.js + return transpile.call(loader, load) + .then(function(source) { + // clear sourceMap as transpiler embeds it + load.metadata.sourceMap = undefined; + return source; + }); + }, function(err) { + throw addToError(err, 'Unable to load transpiler to transpile ' + load.name); + }); + } + + // skip transpiler and transpiler runtime loading when transpiler is disabled + if (loader.transpiler === false) + return source; + + // load the transpiler correctly + if (loader._loader.loadedTranspiler === false && (loader.transpiler == 'traceur' || loader.transpiler == 'typescript' || loader.transpiler == 'babel') + && load.name == loader.normalizeSync(loader.transpiler)) { + + // always load transpiler as a global + if (source.length > 100 && !load.metadata.format) { + load.metadata.format = 'global'; + + if (loader.transpiler === 'traceur') + load.metadata.exports = 'traceur'; + if (loader.transpiler === 'typescript') + load.metadata.exports = 'ts'; + } + + loader._loader.loadedTranspiler = true; + } + + // load the transpiler runtime correctly + if (loader._loader.loadedTranspilerRuntime === false) { + if (load.name == loader.normalizeSync('traceur-runtime') + || load.name == loader.normalizeSync('babel/external-helpers*')) { + if (source.length > 100) + load.metadata.format = load.metadata.format || 'global'; + + loader._loader.loadedTranspilerRuntime = true; + } + } + + // detect transpiler runtime usage to load runtimes + if ((load.metadata.format == 'register' || load.metadata.bundle) && loader._loader.loadedTranspilerRuntime !== true) { + if (loader.transpiler == 'traceur' && !__global.$traceurRuntime && load.source.match(traceurRuntimeRegEx)) { + loader._loader.loadedTranspilerRuntime = loader._loader.loadedTranspilerRuntime || false; + return loader['import']('traceur-runtime').then(function() { + return source; + }); + } + if (loader.transpiler == 'babel' && !__global.babelHelpers && load.source.match(babelHelpersRegEx)) { + loader._loader.loadedTranspilerRuntime = loader._loader.loadedTranspilerRuntime || false; + return loader['import']('babel/external-helpers').then(function() { + return source; + }); + } + } + + return source; + }); + }; + }); + +})(); |