parcel-bundler
Version:
Blazing fast, zero configuration web application bundler
452 lines (347 loc) • 15.5 kB
JavaScript
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var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
var _slicedToArray2 = _interopRequireDefault(require("@babel/runtime/helpers/slicedToArray"));
function _createForOfIteratorHelper(o, allowArrayLike) { var it; if (typeof Symbol === "undefined" || o[Symbol.iterator] == null) { if (Array.isArray(o) || (it = _unsupportedIterableToArray(o)) || allowArrayLike && o && typeof o.length === "number") { if (it) o = it; var i = 0; var F = function F() {}; return { s: F, n: function n() { if (i >= o.length) return { done: true }; return { done: false, value: o[i++] }; }, e: function e(_e) { throw _e; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var normalCompletion = true, didErr = false, err; return { s: function s() { it = o[Symbol.iterator](); }, n: function n() { var step = it.next(); normalCompletion = step.done; return step; }, e: function e(_e2) { didErr = true; err = _e2; }, f: function f() { try { if (!normalCompletion && it.return != null) it.return(); } finally { if (didErr) throw err; } } }; }
function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }
function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i]; return arr2; }
const _require = require('path'),
relative = _require.relative;
const template = require('@babel/template').default;
const t = require('@babel/types');
const traverse = require('@babel/traverse').default;
const generate = require('@babel/generator').default;
const treeShake = require('./shake');
const mangleScope = require('./mangler');
const _require2 = require('./utils'),
getName = _require2.getName,
getIdentifier = _require2.getIdentifier;
const EXPORTS_RE = /^\$([^$]+)\$exports$/;
const ESMODULE_TEMPLATE = template(`$parcel$defineInteropFlag(EXPORTS);`);
const DEFAULT_INTEROP_TEMPLATE = template('var NAME = $parcel$interopDefault(MODULE)');
const THROW_TEMPLATE = template('$parcel$missingModule(MODULE)');
const REQUIRE_TEMPLATE = template('require(ID)');
module.exports = (packager, ast) => {
let assets = packager.assets;
let replacements = new Map();
let imports = new Map();
let referenced = new Set(); // Build a mapping of all imported identifiers to replace.
var _iterator = _createForOfIteratorHelper(assets.values()),
_step;
try {
for (_iterator.s(); !(_step = _iterator.n()).done;) {
let asset = _step.value;
for (let name in asset.cacheData.imports) {
let imp = asset.cacheData.imports[name];
imports.set(name, [packager.resolveModule(asset.id, imp[0]), imp[1]]);
}
}
} catch (err) {
_iterator.e(err);
} finally {
_iterator.f();
}
function replaceExportNode(module, originalName, path) {
let _packager$findExportM = packager.findExportModule(module.id, originalName, replacements),
identifier = _packager$findExportM.identifier,
name = _packager$findExportM.name,
id = _packager$findExportM.id;
let mod = assets.get(id);
let node;
if (identifier) {
node = findSymbol(path, identifier);
} // If the module is not in this bundle, create a `require` call for it.
if (!node && !mod) {
node = REQUIRE_TEMPLATE({
ID: t.stringLiteral(id)
}).expression;
return interop(module, name, path, node);
} // If this is an ES6 module, throw an error if we cannot resolve the module
if (!node && !mod.cacheData.isCommonJS && mod.cacheData.isES6Module) {
let relativePath = relative(packager.options.rootDir, mod.name);
throw new Error(`${relativePath} does not export '${name}'`);
} // If it is CommonJS, look for an exports object.
if (!node && mod.cacheData.isCommonJS) {
node = findSymbol(path, getName(mod, 'exports'));
if (!node) {
return null;
}
return interop(mod, name, path, node);
}
return node;
}
function findSymbol(path, symbol) {
if (replacements.has(symbol)) {
symbol = replacements.get(symbol);
} // if the symbol is in the scope there is not need to remap it
if (path.scope.getProgramParent().hasBinding(symbol)) {
return t.identifier(symbol);
}
return null;
}
function interop(mod, originalName, path, node) {
// Handle interop for default imports of CommonJS modules.
if (mod.cacheData.isCommonJS && originalName === 'default') {
let name = getName(mod, '$interop$default');
if (!path.scope.getBinding(name)) {
let _path$getStatementPar = path.getStatementParent().insertBefore(DEFAULT_INTEROP_TEMPLATE({
NAME: t.identifier(name),
MODULE: node
})),
_path$getStatementPar2 = (0, _slicedToArray2.default)(_path$getStatementPar, 1),
decl = _path$getStatementPar2[0];
let binding = path.scope.getBinding(getName(mod, 'exports'));
if (binding) {
binding.reference(decl.get('declarations.0.init'));
}
path.scope.registerDeclaration(decl);
}
return t.memberExpression(t.identifier(name), t.identifier('d'));
} // if there is a CommonJS export return $id$exports.name
if (originalName !== '*') {
return t.memberExpression(node, t.identifier(originalName));
}
return node;
}
function isUnusedValue(path) {
return path.parentPath.isExpressionStatement() || path.parentPath.isSequenceExpression() && (path.key !== path.container.length - 1 || isUnusedValue(path.parentPath));
}
traverse(ast, {
CallExpression(path) {
let _path$node = path.node,
args = _path$node.arguments,
callee = _path$node.callee;
if (!t.isIdentifier(callee)) {
return;
} // each require('module') call gets replaced with $parcel$require(id, 'module')
if (callee.name === '$parcel$require') {
let _args = (0, _slicedToArray2.default)(args, 2),
id = _args[0],
source = _args[1];
if (args.length !== 2 || !t.isStringLiteral(id) || !t.isStringLiteral(source)) {
throw new Error('invariant: invalid signature, expected : $parcel$require(number, string)');
}
let asset = assets.get(id.value);
let mod = packager.resolveModule(id.value, source.value);
if (!mod) {
if (asset.dependencies.get(source.value).optional) {
path.replaceWith(THROW_TEMPLATE({
MODULE: t.stringLiteral(source.value)
}));
} else {
throw new Error(`Cannot find module "${source.value}" in asset ${id.value}`);
}
} else {
let node;
if (assets.get(mod.id)) {
// Replace with nothing if the require call's result is not used.
if (!isUnusedValue(path)) {
let name = getName(mod, 'exports');
node = t.identifier(replacements.get(name) || name); // Insert __esModule interop flag if the required module is an ES6 module with a default export.
// This ensures that code generated by Babel and other tools works properly.
if (asset.cacheData.isCommonJS && mod.cacheData.isES6Module && mod.cacheData.exports.default) {
let binding = path.scope.getBinding(name);
if (binding && !binding.path.getData('hasESModuleFlag')) {
if (binding.path.node.init) {
binding.path.getStatementParent().insertAfter(ESMODULE_TEMPLATE({
EXPORTS: name
}));
}
var _iterator2 = _createForOfIteratorHelper(binding.constantViolations),
_step2;
try {
for (_iterator2.s(); !(_step2 = _iterator2.n()).done;) {
let path = _step2.value;
path.insertAfter(ESMODULE_TEMPLATE({
EXPORTS: name
}));
}
} catch (err) {
_iterator2.e(err);
} finally {
_iterator2.f();
}
binding.path.setData('hasESModuleFlag', true);
}
}
} // We need to wrap the module in a function when a require
// call happens inside a non top-level scope, e.g. in a
// function, if statement, or conditional expression.
if (mod.cacheData.shouldWrap) {
let call = t.callExpression(getIdentifier(mod, 'init'), []);
node = node ? t.sequenceExpression([call, node]) : call;
}
} else {
node = REQUIRE_TEMPLATE({
ID: t.stringLiteral(mod.id)
}).expression;
}
if (node) {
path.replaceWith(node);
} else {
path.remove();
}
}
} else if (callee.name === '$parcel$require$resolve') {
let _args2 = (0, _slicedToArray2.default)(args, 2),
id = _args2[0],
source = _args2[1];
if (args.length !== 2 || !t.isStringLiteral(id) || !t.isStringLiteral(source)) {
throw new Error('invariant: invalid signature, expected : $parcel$require$resolve(number, string)');
}
let mapped = assets.get(id.value);
let dep = mapped.dependencies.get(source.value);
let mod = mapped.depAssets.get(dep);
let bundles = mod.id;
if (dep.dynamic && packager.bundle.childBundles.has(mod.parentBundle)) {
bundles = [];
var _iterator3 = _createForOfIteratorHelper(mod.parentBundle.siblingBundles),
_step3;
try {
for (_iterator3.s(); !(_step3 = _iterator3.n()).done;) {
let child = _step3.value;
if (!child.isEmpty && packager.options.bundleLoaders[child.type]) {
bundles.push(packager.getBundleSpecifier(child));
}
}
} catch (err) {
_iterator3.e(err);
} finally {
_iterator3.f();
}
bundles.push(packager.getBundleSpecifier(mod.parentBundle));
bundles.push(mod.id);
}
path.replaceWith(t.valueToNode(bundles));
}
},
VariableDeclarator: {
exit(path) {
// Replace references to declarations like `var x = require('x')`
// with the final export identifier instead.
// This allows us to potentially replace accesses to e.g. `x.foo` with
// a variable like `$id$export$foo` later, avoiding the exports object altogether.
let _path$node2 = path.node,
id = _path$node2.id,
init = _path$node2.init;
if (!t.isIdentifier(init)) {
return;
}
let match = init.name.match(EXPORTS_RE);
if (!match) {
return;
} // Replace patterns like `var {x} = require('y')` with e.g. `$id$export$x`.
if (t.isObjectPattern(id)) {
var _iterator4 = _createForOfIteratorHelper(path.get('id.properties')),
_step4;
try {
for (_iterator4.s(); !(_step4 = _iterator4.n()).done;) {
let p = _step4.value;
let _p$node = p.node,
computed = _p$node.computed,
key = _p$node.key,
value = _p$node.value;
if (computed || !t.isIdentifier(key) || !t.isIdentifier(value)) {
continue;
}
let _packager$findExportM2 = packager.findExportModule(match[1], key.name, replacements),
identifier = _packager$findExportM2.identifier;
if (identifier) {
replace(value.name, identifier, p);
}
}
} catch (err) {
_iterator4.e(err);
} finally {
_iterator4.f();
}
if (id.properties.length === 0) {
path.remove();
}
} else if (t.isIdentifier(id)) {
replace(id.name, init.name, path);
}
function replace(id, init, path) {
let binding = path.scope.getBinding(id);
if (!binding.constant) {
return;
}
var _iterator5 = _createForOfIteratorHelper(binding.referencePaths),
_step5;
try {
for (_iterator5.s(); !(_step5 = _iterator5.n()).done;) {
let ref = _step5.value;
ref.replaceWith(t.identifier(init));
}
} catch (err) {
_iterator5.e(err);
} finally {
_iterator5.f();
}
replacements.set(id, init);
path.remove();
}
}
},
MemberExpression: {
exit(path) {
if (!path.isReferenced()) {
return;
}
let _path$node3 = path.node,
object = _path$node3.object,
property = _path$node3.property,
computed = _path$node3.computed;
if (!(t.isIdentifier(object) && (t.isIdentifier(property) && !computed || t.isStringLiteral(property)))) {
return;
}
let match = object.name.match(EXPORTS_RE); // If it's a $id$exports.name expression.
if (match) {
let name = t.isIdentifier(property) ? property.name : property.value;
let _packager$findExportM3 = packager.findExportModule(match[1], name, replacements),
identifier = _packager$findExportM3.identifier; // Check if $id$export$name exists and if so, replace the node by it.
if (identifier) {
path.replaceWith(t.identifier(identifier));
}
}
}
},
ReferencedIdentifier(path) {
let name = path.node.name;
if (typeof name !== 'string') {
return;
}
if (imports.has(name)) {
let imp = imports.get(name);
let node = replaceExportNode(imp[0], imp[1], path); // If the export does not exist, replace with an empty object.
if (!node) {
node = t.objectExpression([]);
}
path.replaceWith(node);
return;
}
let match = name.match(EXPORTS_RE);
if (match) {
referenced.add(name);
} // If it's an undefined $id$exports identifier.
if (match && !path.scope.hasBinding(name)) {
path.replaceWith(t.objectExpression([]));
}
},
Program: {
// A small optimization to remove unused CommonJS exports as sometimes Uglify doesn't remove them.
exit(path) {
treeShake(path.scope);
if (packager.options.minify) {
mangleScope(path.scope);
}
}
}
});
let opts = {
sourceMaps: packager.options.sourceMaps,
sourceFileName: packager.bundle.name,
minified: packager.options.minify,
comments: !packager.options.minify
};
return generate(ast, opts);
};