move babel to main thread

There are many failing tests, but it basically works.

Author: jamestalmage

api.js

@@ -8,8 +8,10 @@ var Promise = require('bluebird');
 var figures = require('figures');
 var globby = require('globby');
 var chalk = require('chalk');
+var assign = require('object-assign');
 var fork = require('./lib/fork');
 var formatter = require('./lib/enhance-assert').formatter();
+var precompileTest = require('./lib/test-transformer');
 
 function Api(files, options) {
 	if (!(this instanceof Api)) {
@@ -40,7 +42,15 @@ util.inherits(Api, EventEmitter);
 module.exports = Api;
 
 Api.prototype._runFile = function (file) {
-	return fork(file, this.options)
+	var precompiled = {};
+	precompiled[file.testPath] = {
+		sourcePath: file.tempPath,
+		mapPath: file.mapPath
+	};
+	var options = assign({}, this.options, {
+		precompiled: precompiled
+	});
+	return fork(file.testPath, options)
 		.on('stats', this._handleStats)
 		.on('test', this._handleTest)
 		.on('unhandledRejections', this._handleRejections)
@@ -129,6 +139,7 @@ Api.prototype.run = function () {
 		.map(function (file) {
 			return path.resolve(file);
 		})
+		.map(precompileTest)
 		.then(function (files) {
 			if (files.length === 0) {
 				return Promise.reject(new Error('Couldn\'t find any files to test'));

lib/babel.js

@@ -23,59 +23,41 @@ var resolveCwd = require('resolve-cwd');
 
 var sourceMapCache = Object.create(null);
 
+var fs = require('fs');
 var sourceMapSupport = require('source-map-support');
 sourceMapSupport.install({
 	handleUncaughtExceptions: false,
 	retrieveSourceMap: function (source) {
 		if (sourceMapCache[source]) {
 			return {
 				url: source,
-				map: sourceMapCache[source]
+				map: fs.readFileSync(sourceMapCache[source], 'utf8')
 			};
 		}
 	}
 });
 
-var createEspowerPlugin = require('babel-plugin-espower/create');
-var requireFromString = require('require-from-string');
 var loudRejection = require('loud-rejection/api')(process);
 var serializeError = require('serialize-error');
-var babel = require('babel-core');
 var send = require('./send');
+var installPrecompiler = require('require-precompiled');
 
 var testPath = opts.file;
 
-// initialize power-assert
-var powerAssert = createEspowerPlugin(babel, {
-	patterns: require('./enhance-assert').PATTERNS
-});
-
-// if generators are not supported, use regenerator
-var options = {
-	presets: [require('babel-preset-stage-2'), require('babel-preset-es2015')],
-	plugins: [powerAssert, require('babel-plugin-transform-runtime')],
-	sourceMaps: true
-};
-
 // check if test files required ava and show error, when they didn't
 exports.avaRequired = false;
 
-// try to load an input source map for the test file, in case the file was
-// already compiled once by the user
-var inputSourceMap = sourceMapSupport.retrieveSourceMap(testPath);
-if (inputSourceMap) {
-	// source-map-support returns the source map as a json-encoded string, but
-	// babel requires an actual object
-	options.inputSourceMap = JSON.parse(inputSourceMap.map);
-}
-
-// include test file
-var transpiled = babel.transformFileSync(testPath, options);
-sourceMapCache[testPath] = transpiled.map;
-requireFromString(transpiled.code, testPath, {
-	appendPaths: module.paths
+installPrecompiler(function (filename) {
+	var precompiled = opts.precompiled[filename];
+	if (precompiled) {
+		sourceMapCache[filename] = precompiled.mapPath;
+		return fs.readFileSync(precompiled.sourcePath, 'utf8');
+	}
+	return null;
 });
 
+require(testPath);
+
 process.on('uncaughtException', function (exception) {
 	send('uncaughtException', {exception: serializeError(exception)});
 });

lib/test-transformer.js

@@ -0,0 +1,55 @@
+var createEspowerPlugin = require('babel-plugin-espower/create');
+var sourceMapSupport = require('source-map-support');
+var babel = require('babel-core');
+var Promise = require('bluebird');
+var tempWrite = require('temp-write');
+var transformFile = Promise.promisify(babel.transformFile);
+var enhanceAssert = require('./enhance-assert');
+
+var cache = {};
+
+module.exports = precompile;
+
+function precompile(testPath) {
+	return cache[testPath] || (cache[testPath] = _precompile(testPath));
+}
+
+function _precompile(testPath) {
+	// initialize power-assert
+	var powerAssert = createEspowerPlugin(babel, {
+		patterns: enhanceAssert.PATTERNS
+	});
+
+	// if generators are not supported, use regenerator
+	var options = {
+		presets: [require('babel-preset-stage-2'), require('babel-preset-es2015')],
+		plugins: [powerAssert, require('babel-plugin-transform-runtime')],
+		sourceMaps: true,
+		ast: false,
+		inputSourceMap: null
+	};
+
+	// try to load an input source map for the test file, in case the file was
+	// already compiled once by the user
+	var inputSourceMap = sourceMapSupport.retrieveSourceMap(testPath);
+	if (inputSourceMap) {
+		// source-map-support returns the source map as a json-encoded string, but
+		// babel requires an actual object
+		options.inputSourceMap = JSON.parse(inputSourceMap.map);
+	}
+
+	return transformFile(testPath, options)
+		.then(function (result) {
+			return Promise.all([
+				tempWrite(result.code, testPath),
+				tempWrite(JSON.stringify(result.map), testPath + '.map')
+			])
+				.spread(function (tempPath, mapPath) {
+					result.mapPath = mapPath;
+					result.tempPath = tempPath;
+					result.testPath = testPath;
+					return result;
+				});
+		});
+}
+

package.json

@@ -110,11 +110,14 @@
     "power-assert-renderers": "^0.1.0",
     "pretty-ms": "^2.0.0",
     "require-from-string": "^1.1.0",
+    "require-precompiled": "^0.1.0",
     "resolve-cwd": "^1.0.0",
+    "resolve-from": "^2.0.0",
     "serialize-error": "^1.1.0",
     "set-immediate-shim": "^1.0.1",
     "source-map-support": "^0.4.0",
     "squeak": "^1.2.0",
+    "temp-write": "^2.1.0",
     "time-require": "^0.1.2",
     "update-notifier": "^0.5.0"
   },