babel/lib/6to5/transform.js

139 lines
4.4 KiB
JavaScript

var sourceMap = require("source-map");
var traverse = require("./traverse");
var recast = require("recast");
var util = require("./util");
var _ = require("lodash");
var ensureTransformerNames = function (type, keys) {
_.each(keys, function (key) {
if (!transform.transformers[key]) {
throw new ReferenceError("unknown transformer " + key + " specified in " + type);
}
});
};
var transform = module.exports = function (code, opts) {
opts = opts || {};
code = (code || "") + "";
_.defaults(opts, {
blacklist: [],
whitelist: [],
sourceMap: false,
filename: "unknown",
format: {}
});
_.defaults(opts, {
sourceFileName: opts.filename,
sourceMapName: opts.filename
});
ensureTransformerNames("blacklist", opts.blacklist);
ensureTransformerNames("whitelist", opts.whitelist);
return util.parse(opts, code, function (tree) {
return transform._run(code, tree, opts);
});
};
transform._run = function (code, tree, opts) {
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 result = util.generate(tree, opts);
if (opts.sourceMap === "inline") {
result.code += "\n" + util.sourceMapToComment(result.map);
}
result.map = result.map || null;
result.ast = tree;
return result;
};
transform._runTransformer = function (transformer, tree, opts, generateUid) {
var build = function (exit) {
return function (node, parent) {
var fns = transformer[node.type] || transformer.all;
if (!fns) return;
var fn = fns.enter || fns;
if (exit) fn = fns.exit;
if (!fn || !_.isFunction(fn)) return;
return fn(node, parent, opts, generateUid);
};
};
traverse(tree, {
enter: build(),
exit: build(true)
});
};
transform.test = function (task, assert) {
var actual = task.actual;
var expect = task.expect;
var opts = task.options;
opts.filename = actual.filename;
var actualCode = actual.code.trim();
var actualResult = transform(actualCode, opts);
var actualAst = actualResult.ast;
actualCode = recast.prettyPrint(actualAst).code;
var expectCode = expect.code.trim();
var expectAst = util.parse(expect, expectCode);
var expectResult = recast.prettyPrint(expectAst);
expectCode = expectResult.code;
assert.equal(actualCode, expectCode);
if (task.sourceMap) {
assert.deepEqual(task.sourceMap, actualResult.map);
}
if (task.sourceMappings) {
var consumer = new sourceMap.SourceMapConsumer(actualResult.map);
_.each(task.sourceMappings, function (mapping, i) {
var pos = consumer.originalPositionFor(mapping.generated);
var msg = "source mapping " + ++i + " - generated: " + mapping.generated.line + ":" + mapping.generated.column;
assert.equal(pos.line + ":" + pos.column, mapping.original.line + ":" + mapping.original.column, msg);
});
}
};
transform.transformers = {
modules: require("./transformers/modules"),
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"),
generators: require("./transformers/generators"),
blockBinding: require("./transformers/block-binding"),
restParameters: require("./transformers/rest-parameters"),
destructuring: require("./transformers/destructuring"),
forOf: require("./transformers/for-of"),
unicodeRegex: require("./transformers/unicode-regex")
};