babel/lib/6to5/transform.js

119 lines
3.6 KiB
JavaScript

var escodegen = require("escodegen");
var traverse = require("./traverse");
var assert = require("assert");
var util = require("./util");
var _ = require("lodash");
var transform = module.exports = function (code, opts) {
opts = opts || {};
_.defaults(opts, {
sourceMapObject: false,
blacklist: [],
whitelist: [],
sourceMap: false,
filename: "unknown",
format: {}
});
if (opts.sourceMapObject) opts.sourceMap = true;
return util.parse(opts.filename, code, function (tree) {
return transform._run(code, tree, opts);
}, true);
};
transform._run = function (code, tree, opts) {
traverse.replace(tree, function (node) {
if (node.type === "EmptyStatement") {
return traverse.Delete;
}
});
var generateUid = util.buildUidGenerator();
_.each(transform.transformers, function (transformer, name) {
var blacklist = opts.blacklist;
if (blacklist.length && _.contains(blacklist, name)) return;
var whitelist = opts.whitelist;
if (whitelist.length && !_.contains(whitelist, name)) return;
transform._runTransformer(transformer, tree, opts, generateUid);
});
var genOpts = {
comment: true,
format: _.merge(opts.format, {
indent: {
style: " "
}
})
};
if (opts.sourceMap) {
genOpts.sourceMap = true;
genOpts.sourceContent = code;
genOpts.sourceMapWithCode = true;
}
var result = escodegen.generate(tree, genOpts);
if (genOpts.sourceMapWithCode) {
if (opts.sourceMapObject) {
return result;
} else {
return result.code + "\n" + util.sourceMapToComment(result.map) + "\n";
}
} else {
return result + "\n";
}
};
transform._runTransformer = function (transformer, tree, opts, generateUid) {
if (transformer.Program) transformer.Program(tree, opts);
traverse.replace(tree, function (node, parent) {
var fn = transformer[node.type] || transformer.all;
if (!fn) return;
return fn(node, parent, opts, generateUid);
});
};
transform.test = function (actual, expect, opts, debug) {
opts = opts || {};
_.defaults(opts, { filename: "test" });
var actualCode = actual.code.trim();
var transformedCode = transform(actualCode, opts);
var actualAst = util.parse(actual.filename, transformedCode);
var expectCode = expect.code.trim();
var expectAst = util.parse(expect.filename, expectCode);
actualCode = escodegen.generate(actualAst);
expectCode = escodegen.generate(expectAst);
assert.equal(actualCode, expectCode);
};
transform.transformers = {
computedPropertyNames: require("./transformers/computed-property-names"),
propertyNameShorthand: require("./transformers/property-name-shorthand"),
constants: require("./transformers/constants"),
arrayComprehension: require("./transformers/array-comprehension"),
arrowFunctions: require("./transformers/arrow-functions"),
classes: require("./transformers/classes"),
spread: require("./transformers/spread"),
templateLiterals: require("./transformers/template-literals"),
propertyMethodAssignment: require("./transformers/property-method-assignment"),
defaultParameters: require("./transformers/default-parameters"),
destructuring: require("./transformers/destructuring"),
generators: require("./transformers/generators"),
blockBinding: require("./transformers/block-binding"),
modules: require("./transformers/modules"),
restParameters: require("./transformers/rest-parameters"),
forOf: require("./transformers/for-of")
};