2017-02-21 16:52:42 -08:00

488 lines
17 KiB
JavaScript

import { basename, extname } from "path";
import template from "babel-template";
import * as t from "babel-types";
import transformStrictMode from "babel-plugin-transform-strict-mode";
const buildRequire = template(`
require($0);
`);
const buildExportsModuleDeclaration = template(`
Object.defineProperty(exports, "__esModule", {
value: true
});
`);
const buildExportsFrom = template(`
Object.defineProperty(exports, $0, {
enumerable: true,
get: function () {
return $1;
}
});
`);
const buildLooseExportsModuleDeclaration = template(`
exports.__esModule = true;
`);
const buildExportsAssignment = template(`
exports.$0 = $1;
`);
const buildExportAll = template(`
Object.keys(OBJECT).forEach(function (key) {
if (key === "default" || key === "__esModule") return;
Object.defineProperty(exports, key, {
enumerable: true,
get: function () {
return OBJECT[key];
}
});
});
`);
const THIS_BREAK_KEYS = ["FunctionExpression", "FunctionDeclaration", "ClassProperty",
"ClassMethod", "ObjectMethod"];
export default function () {
const REASSIGN_REMAP_SKIP = Symbol();
const reassignmentVisitor = {
ReferencedIdentifier(path) {
const name = path.node.name;
const remap = this.remaps[name];
if (!remap) return;
// redeclared in this scope
if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
if (path.parentPath.isCallExpression({ callee: path.node })) {
path.replaceWith(t.sequenceExpression([t.numericLiteral(0), remap]));
} else if (path.isJSXIdentifier() && t.isMemberExpression(remap)) {
const { object, property } = remap;
path.replaceWith(t.JSXMemberExpression(t.JSXIdentifier(object.name),
t.JSXIdentifier(property.name)));
} else {
path.replaceWith(remap);
}
this.requeueInParent(path);
},
AssignmentExpression(path) {
let node = path.node;
if (node[REASSIGN_REMAP_SKIP]) return;
const left = path.get("left");
if (!left.isIdentifier()) return;
const name = left.node.name;
const exports = this.exports[name];
if (!exports) return;
// redeclared in this scope
if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
node[REASSIGN_REMAP_SKIP] = true;
for (const reid of exports) {
node = buildExportsAssignment(reid, node).expression;
}
path.replaceWith(node);
this.requeueInParent(path);
},
UpdateExpression(path) {
const arg = path.get("argument");
if (!arg.isIdentifier()) return;
const name = arg.node.name;
const exports = this.exports[name];
if (!exports) return;
// redeclared in this scope
if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
const node = t.assignmentExpression(path.node.operator[0] + "=", arg.node, t.numericLiteral(1));
if ((path.parentPath.isExpressionStatement() && !path.isCompletionRecord()) || path.node.prefix) {
path.replaceWith(node);
this.requeueInParent(path);
return;
}
const nodes = [];
nodes.push(node);
let operator;
if (path.node.operator === "--") {
operator = "+";
} else { // "++"
operator = "-";
}
nodes.push(t.binaryExpression(operator, arg.node, t.numericLiteral(1)));
path.replaceWithMultiple(t.sequenceExpression(nodes));
}
};
return {
inherits: transformStrictMode,
visitor: {
ThisExpression(path, state) {
// If other plugins run after this plugin's Program#exit handler, we allow them to
// insert top-level `this` values. This allows the AMD and UMD plugins to
// function properly.
if (this.ranCommonJS) return;
if (
state.opts.allowTopLevelThis !== true &&
!path.findParent((path) => !path.is("shadow") &&
THIS_BREAK_KEYS.indexOf(path.type) >= 0)
) {
path.replaceWith(t.identifier("undefined"));
}
},
Program: {
exit(path) {
this.ranCommonJS = true;
const strict = !!this.opts.strict;
const { scope } = path;
// rename these commonjs variables if they're declared in the file
scope.rename("module");
scope.rename("exports");
scope.rename("require");
let hasExports = false;
let hasImports = false;
const body: Array<Object> = path.get("body");
const imports = Object.create(null);
const exports = Object.create(null);
const nonHoistedExportNames = Object.create(null);
const topNodes = [];
const remaps = Object.create(null);
const requires = Object.create(null);
function addRequire(source, blockHoist) {
const cached = requires[source];
if (cached) return cached;
const ref = path.scope.generateUidIdentifier(basename(source, extname(source)));
const varDecl = t.variableDeclaration("var", [
t.variableDeclarator(ref, buildRequire(
t.stringLiteral(source)
).expression)
]);
// Copy location from the original import statement for sourcemap
// generation.
if (imports[source]) {
varDecl.loc = imports[source].loc;
}
if (typeof blockHoist === "number" && blockHoist > 0) {
varDecl._blockHoist = blockHoist;
}
topNodes.push(varDecl);
return requires[source] = ref;
}
function addTo(obj, key, arr) {
const existing = obj[key] || [];
obj[key] = existing.concat(arr);
}
for (const path of body) {
if (path.isExportDeclaration()) {
hasExports = true;
const specifiers = [].concat(path.get("declaration"), path.get("specifiers"));
for (const specifier of specifiers) {
const ids = specifier.getBindingIdentifiers();
if (ids.__esModule) {
throw specifier.buildCodeFrameError("Illegal export \"__esModule\"");
}
}
}
if (path.isImportDeclaration()) {
hasImports = true;
const key = path.node.source.value;
const importsEntry = imports[key] || {
specifiers: [],
maxBlockHoist: 0,
loc: path.node.loc,
};
importsEntry.specifiers.push(...path.node.specifiers);
if (typeof path.node._blockHoist === "number") {
importsEntry.maxBlockHoist = Math.max(
path.node._blockHoist,
importsEntry.maxBlockHoist
);
}
imports[key] = importsEntry;
path.remove();
} else if (path.isExportDefaultDeclaration()) {
const declaration = path.get("declaration");
if (declaration.isFunctionDeclaration()) {
const id = declaration.node.id;
const defNode = t.identifier("default");
if (id) {
addTo(exports, id.name, defNode);
topNodes.push(buildExportsAssignment(defNode, id));
path.replaceWith(declaration.node);
} else {
topNodes.push(buildExportsAssignment(defNode, t.toExpression(declaration.node)));
path.remove();
}
} else if (declaration.isClassDeclaration()) {
const id = declaration.node.id;
const defNode = t.identifier("default");
if (id) {
addTo(exports, id.name, defNode);
path.replaceWithMultiple([
declaration.node,
buildExportsAssignment(defNode, id)
]);
} else {
path.replaceWith(buildExportsAssignment(defNode, t.toExpression(declaration.node)));
// Manualy re-queue `export default class {}` expressions so that the ES3 transform
// has an opportunity to convert them. Ideally this would happen automatically from the
// replaceWith above. See #4140 for more info.
path.parentPath.requeue(path.get("expression.left"));
}
} else {
path.replaceWith(buildExportsAssignment(t.identifier("default"), declaration.node));
// Manualy re-queue `export default foo;` expressions so that the ES3 transform
// has an opportunity to convert them. Ideally this would happen automatically from the
// replaceWith above. See #4140 for more info.
path.parentPath.requeue(path.get("expression.left"));
}
} else if (path.isExportNamedDeclaration()) {
const declaration = path.get("declaration");
if (declaration.node) {
if (declaration.isFunctionDeclaration()) {
const id = declaration.node.id;
addTo(exports, id.name, id);
topNodes.push(buildExportsAssignment(id, id));
path.replaceWith(declaration.node);
} else if (declaration.isClassDeclaration()) {
const id = declaration.node.id;
addTo(exports, id.name, id);
path.replaceWithMultiple([
declaration.node,
buildExportsAssignment(id, id)
]);
nonHoistedExportNames[id.name] = true;
} else if (declaration.isVariableDeclaration()) {
const declarators = declaration.get("declarations");
for (const decl of declarators) {
const id = decl.get("id");
const init = decl.get("init");
if (!init.node) init.replaceWith(t.identifier("undefined"));
if (id.isIdentifier()) {
addTo(exports, id.node.name, id.node);
init.replaceWith(buildExportsAssignment(id.node, init.node).expression);
nonHoistedExportNames[id.node.name] = true;
} else {
// todo
}
}
path.replaceWith(declaration.node);
}
continue;
}
const specifiers = path.get("specifiers");
const nodes = [];
const source = path.node.source;
if (source) {
const ref = addRequire(source.value, path.node._blockHoist);
for (const specifier of specifiers) {
if (specifier.isExportNamespaceSpecifier()) {
// todo
} else if (specifier.isExportDefaultSpecifier()) {
// todo
} else if (specifier.isExportSpecifier()) {
if (specifier.node.local.name === "default") {
topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name),
t.memberExpression(
t.callExpression(this.addHelper("interopRequireDefault"), [ref]),
specifier.node.local
)
));
} else {
topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name),
t.memberExpression(ref, specifier.node.local)));
}
nonHoistedExportNames[specifier.node.exported.name] = true;
}
}
} else {
for (const specifier of specifiers) {
if (specifier.isExportSpecifier()) {
addTo(exports, specifier.node.local.name, specifier.node.exported);
nonHoistedExportNames[specifier.node.exported.name] = true;
nodes.push(buildExportsAssignment(specifier.node.exported, specifier.node.local));
}
}
}
path.replaceWithMultiple(nodes);
} else if (path.isExportAllDeclaration()) {
const exportNode = buildExportAll({
OBJECT: addRequire(path.node.source.value, path.node._blockHoist)
});
exportNode.loc = path.node.loc;
topNodes.push(exportNode);
path.remove();
}
}
for (const source in imports) {
const { specifiers, maxBlockHoist } = imports[source];
if (specifiers.length) {
const uid = addRequire(source, maxBlockHoist);
let wildcard;
for (let i = 0; i < specifiers.length; i++) {
const specifier = specifiers[i];
if (t.isImportNamespaceSpecifier(specifier)) {
if (strict) {
remaps[specifier.local.name] = uid;
} else {
const varDecl = t.variableDeclaration("var", [
t.variableDeclarator(
specifier.local,
t.callExpression(
this.addHelper("interopRequireWildcard"),
[uid]
)
)
]);
if (maxBlockHoist > 0) {
varDecl._blockHoist = maxBlockHoist;
}
topNodes.push(varDecl);
}
wildcard = specifier.local;
} else if (t.isImportDefaultSpecifier(specifier)) {
specifiers[i] = t.importSpecifier(specifier.local, t.identifier("default"));
}
}
for (const specifier of specifiers) {
if (t.isImportSpecifier(specifier)) {
let target = uid;
if (specifier.imported.name === "default") {
if (wildcard) {
target = wildcard;
} else {
target = wildcard = path.scope.generateUidIdentifier(uid.name);
const varDecl = t.variableDeclaration("var", [
t.variableDeclarator(
target,
t.callExpression(
this.addHelper("interopRequireDefault"),
[uid]
)
)
]);
if (maxBlockHoist > 0) {
varDecl._blockHoist = maxBlockHoist;
}
topNodes.push(varDecl);
}
}
remaps[specifier.local.name] = t.memberExpression(target,
t.cloneWithoutLoc(specifier.imported));
}
}
} else {
// bare import
const requireNode = buildRequire(t.stringLiteral(source));
requireNode.loc = imports[source].loc;
topNodes.push(requireNode);
}
}
if (hasImports && Object.keys(nonHoistedExportNames).length) {
// avoid creating too long of export assignment to prevent stack overflow
const maxHoistedExportsNodeAssignmentLength = 100;
const nonHoistedExportNamesArr = Object.keys(nonHoistedExportNames);
for (
let currentExportsNodeAssignmentLength = 0;
currentExportsNodeAssignmentLength < nonHoistedExportNamesArr.length;
currentExportsNodeAssignmentLength += maxHoistedExportsNodeAssignmentLength
) {
const nonHoistedExportNamesChunk = nonHoistedExportNamesArr.slice(
currentExportsNodeAssignmentLength,
currentExportsNodeAssignmentLength + maxHoistedExportsNodeAssignmentLength);
let hoistedExportsNode = t.identifier("undefined");
nonHoistedExportNamesChunk.forEach(function (name) {
hoistedExportsNode = buildExportsAssignment(t.identifier(name), hoistedExportsNode)
.expression;
});
const node = t.expressionStatement(hoistedExportsNode);
node._blockHoist = 3;
topNodes.unshift(node);
}
}
// add __esModule declaration if this file has any exports
if (hasExports && !strict) {
let buildTemplate = buildExportsModuleDeclaration;
if (this.opts.loose) buildTemplate = buildLooseExportsModuleDeclaration;
const declar = buildTemplate();
declar._blockHoist = 3;
topNodes.unshift(declar);
}
path.unshiftContainer("body", topNodes);
path.traverse(reassignmentVisitor, {
remaps,
scope,
exports,
requeueInParent: (newPath) => path.requeue(newPath),
});
}
}
}
};
}