com.google.javascript.jscomp.ProcessCommonJSModules Maven / Gradle / Ivy
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/*
* Copyright 2011 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.javascript.jscomp;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableList;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.jscomp.deps.ModuleLoader;
import com.google.javascript.jscomp.deps.ModuleLoader.ModulePath;
import com.google.javascript.rhino.IR;
import com.google.javascript.rhino.JSDocInfo;
import com.google.javascript.rhino.JSDocInfoBuilder;
import com.google.javascript.rhino.Node;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Objects;
/**
* Rewrites a CommonJS module http://wiki.commonjs.org/wiki/Modules/1.1.1 into a form that can be
* safely concatenated. Does not add a function around the module body but instead adds suffixes to
* global variables to avoid conflicts. Calls to require are changed to reference the required
* module directly.
*/
public final class ProcessCommonJSModules extends NodeTraversal.AbstractPreOrderCallback
implements CompilerPass {
private static final String EXPORTS = "exports";
private static final String MODULE = "module";
private static final String REQUIRE = "require";
private static final String WEBPACK_REQUIRE = "__webpack_require__";
// Webpack transpiles import() statements to __webpack_require__.t(modulePath)
// Always imports the module namespace regardless of module type
private static final String WEBPACK_REQUIRE_NAMESPACE = "__webpack_require__.t";
private static final String EXPORT_PROPERTY_NAME = "default";
public static final DiagnosticType UNKNOWN_REQUIRE_ENSURE =
DiagnosticType.warning(
"JSC_COMMONJS_UNKNOWN_REQUIRE_ENSURE_ERROR", "Unrecognized require.ensure call: {0}");
public static final DiagnosticType SUSPICIOUS_EXPORTS_ASSIGNMENT =
DiagnosticType.warning(
"JSC_COMMONJS_SUSPICIOUS_EXPORTS_ASSIGNMENT",
"Suspicious re-assignment of \"exports\" variable."
+ " Did you actually intend to export something?");
private final AbstractCompiler compiler;
/**
* Creates a new ProcessCommonJSModules instance which can be used to rewrite CommonJS modules to
* a concatenable form.
*
* @param compiler The compiler
*/
public ProcessCommonJSModules(AbstractCompiler compiler) {
this.compiler = compiler;
}
@Override
public void process(Node externs, Node root) {
NodeTraversal.traverse(compiler, root, this);
NodeTraversal.traverse(compiler, externs, this);
}
@Override
public boolean shouldTraverse(NodeTraversal t, Node n, Node parent) {
if (n.isRoot()) {
return true;
} else if (n.isScript()) {
if (compiler.getOptions().getModuleResolutionMode() == ModuleLoader.ResolutionMode.WEBPACK) {
removeWebpackModuleShim(n);
}
FindImportsAndExports finder = new FindImportsAndExports();
ErrorHandler moduleLoaderErrorHandler = compiler.getModuleLoader().getErrorHandler();
compiler.getModuleLoader().setErrorHandler(finder);
NodeTraversal.traverse(compiler, n, finder);
CompilerInput.ModuleType moduleType = compiler.getInput(n.getInputId()).getJsModuleType();
boolean forceModuleDetection = moduleType == CompilerInput.ModuleType.IMPORTED_SCRIPT;
boolean defaultExportIsConst = true;
boolean isCommonJsModule = finder.isCommonJsModule();
ImmutableList.Builder exports = ImmutableList.builder();
if (isCommonJsModule || forceModuleDetection) {
if (!finder.umdPatterns.isEmpty()) {
boolean needsRetraverse = false;
if (finder.replaceUmdPatterns()) {
needsRetraverse = true;
}
// Removing the IIFE rewrites vars. We need to re-traverse
// to get the new references.
if (removeIIFEWrapper(n)) {
needsRetraverse = true;
}
if (needsRetraverse) {
finder = new FindImportsAndExports();
compiler.getModuleLoader().setErrorHandler(finder);
NodeTraversal.traverse(compiler, n, finder);
}
}
defaultExportIsConst = finder.initializeModule();
exports.addAll(finder.getModuleExports());
exports.addAll(finder.getExports());
}
finder.reportModuleErrors();
compiler.getModuleLoader().setErrorHandler(moduleLoaderErrorHandler);
NodeTraversal.traverse(
compiler,
n,
new RewriteModule(
isCommonJsModule || forceModuleDetection, exports.build(), defaultExportIsConst));
}
return false;
}
public static String getModuleName(CompilerInput input) {
ModulePath modulePath = input.getPath();
if (modulePath == null) {
return null;
}
return getModuleName(modulePath);
}
public static String getModuleName(ModulePath input) {
return input.toModuleName();
}
String getBasePropertyImport(String moduleName, Node requireCall) {
checkArgument(requireCall.isCall());
if (compiler.getOptions().getModuleResolutionMode() == ModuleLoader.ResolutionMode.WEBPACK
&& requireCall.getFirstChild().matchesQualifiedName(WEBPACK_REQUIRE_NAMESPACE)) {
return moduleName;
}
return getBasePropertyImport(moduleName);
}
public String getBasePropertyImport(String moduleName) {
CompilerInput.ModuleType moduleType = compiler.getModuleTypeByName(moduleName);
if (moduleType != null && moduleType != CompilerInput.ModuleType.COMMONJS) {
return moduleName;
}
return moduleName + "." + EXPORT_PROPERTY_NAME;
}
public boolean isCommonJsImport(Node requireCall) {
return isCommonJsImport(requireCall, compiler.getOptions().getModuleResolutionMode());
}
/**
* Recognize if a node is a module import. We recognize two forms:
*
*
* - require("something");
*
- __webpack_require__(4); // only when the module resolution is WEBPACK
*
- __webpack_require__.t(4); // only when the module resolution is WEBPACK
*
*/
public static boolean isCommonJsImport(
Node requireCall, ModuleLoader.ResolutionMode resolutionMode) {
if (requireCall.isCall() && requireCall.hasTwoChildren()) {
if (resolutionMode == ModuleLoader.ResolutionMode.WEBPACK
&& (requireCall.getFirstChild().matchesQualifiedName(WEBPACK_REQUIRE)
|| requireCall.getFirstChild().matchesQualifiedName(WEBPACK_REQUIRE_NAMESPACE))
&& (requireCall.getSecondChild().isNumber() || requireCall.getSecondChild().isString())) {
return true;
} else if (requireCall.getFirstChild().matchesQualifiedName(REQUIRE)
&& requireCall.getSecondChild().isString()) {
return true;
}
} else if (requireCall.isCall()
&& requireCall.hasXChildren(3)
&& resolutionMode == ModuleLoader.ResolutionMode.WEBPACK
&& requireCall.getFirstChild().matchesQualifiedName(WEBPACK_REQUIRE + ".bind")
&& requireCall.getSecondChild().isNull()
&& (requireCall.getLastChild().isNumber() || requireCall.getLastChild().isString())) {
return true;
}
return false;
}
public String getCommonJsImportPath(Node requireCall) {
return getCommonJsImportPath(requireCall, compiler.getOptions().getModuleResolutionMode());
}
public static String getCommonJsImportPath(
Node requireCall, ModuleLoader.ResolutionMode resolutionMode) {
if (resolutionMode == ModuleLoader.ResolutionMode.WEBPACK) {
Node pathArgument =
requireCall.getChildCount() >= 3
? requireCall.getChildAtIndex(2)
: requireCall.getSecondChild();
if (pathArgument.isNumber()) {
return String.valueOf((int) pathArgument.getDouble());
} else {
return pathArgument.getString();
}
}
return requireCall.getSecondChild().getString();
}
private String getImportedModuleName(NodeTraversal t, Node requireCall) {
return getImportedModuleName(t, requireCall, getCommonJsImportPath(requireCall));
}
private String getImportedModuleName(NodeTraversal t, Node n, String importPath) {
ModulePath modulePath =
t.getInput()
.getPath()
.resolveJsModule(importPath, n.getSourceFileName(), n.getLineno(), n.getCharno());
if (modulePath == null) {
return ModuleIdentifier.forFile(importPath).getModuleName();
}
return modulePath.toModuleName();
}
/**
* Recognize if a node is a module export. We recognize several forms:
*
*
* - module.exports = something;
*
- module.exports.something = something;
*
- exports.something = something;
*
*
* In addition, we only recognize an export if the base export object is not defined or is
* defined in externs.
*/
public static boolean isCommonJsExport(
NodeTraversal t, Node export, ModuleLoader.ResolutionMode resolutionMode) {
if (export.matchesQualifiedName(MODULE + "." + EXPORTS)
|| (export.isGetElem()
&& export.getFirstChild().matchesQualifiedName(MODULE)
&& export.getSecondChild().isString()
&& export.getSecondChild().getString().equals(EXPORTS))) {
Var v = t.getScope().getVar(MODULE);
if (v == null || v.isExtern()) {
return true;
}
} else if (export.isName() && EXPORTS.equals(export.getString())) {
Var v = t.getScope().getVar(export.getString());
if (v == null || v.isGlobal()) {
return true;
}
}
return false;
}
private boolean isCommonJsExport(NodeTraversal t, Node export) {
return ProcessCommonJSModules.isCommonJsExport(
t, export, compiler.getOptions().getModuleResolutionMode());
}
/**
* Recognize if a node is a dynamic module import. Currently only the webpack dynamic import is
* recognized:
*
*
* - __webpack_require__.e(0).then(function() { return __webpack_require__(4);})
*
- Promise.all([__webpack_require__.e(0)]).then(function() { return
* __webpack_require__(4);})
*
*/
public static boolean isCommonJsDynamicImportCallback(
Node n, ModuleLoader.ResolutionMode resolutionMode) {
if (n == null || resolutionMode != ModuleLoader.ResolutionMode.WEBPACK) {
return false;
}
if (n.isFunction() && isWebpackRequireEnsureCallback(n)) {
return true;
}
return false;
}
/**
* Recognizes __webpack_require__ calls that are the .then callback of a __webpack_require__.e
* call. Example:
*
*
* - __webpack_require__.e(0).then(function() { return __webpack_require__(4); })
*
- Promise.all([__webpack_require__.e(0)]).then(function() { return
* __webpack_require__(4);})
*
*/
private static boolean isWebpackRequireEnsureCallback(Node fnc) {
checkArgument(fnc.isFunction());
if (fnc.getParent() == null) {
return false;
}
Node callParent = fnc.getParent();
if (!callParent.isCall()) {
return false;
}
if (!(callParent.hasChildren()
&& callParent.getFirstChild().isGetProp()
&& callParent.getFirstFirstChild().isCall())) {
return false;
}
Node callParentTarget = callParent.getFirstFirstChild().getFirstChild();
if (callParentTarget.matchesQualifiedName(WEBPACK_REQUIRE + ".e")
&& callParent.getFirstChild().getSecondChild().isString()
&& callParent.getFirstChild().getSecondChild().getString().equals("then")) {
return true;
} else if (callParentTarget.matchesQualifiedName("Promise.all")
&& callParentTarget.getNext() != null
&& callParentTarget.getNext().isArrayLit()) {
boolean allElementsAreDynamicImports = false;
for (Node arrayItem = callParentTarget.getNext().getFirstChild();
arrayItem != null;
arrayItem = arrayItem.getNext()) {
if (!(arrayItem.isCall()
&& arrayItem.hasTwoChildren()
&& arrayItem.getFirstChild().matchesQualifiedName(WEBPACK_REQUIRE + ".e"))) {
return false;
}
allElementsAreDynamicImports = true;
}
return allElementsAreDynamicImports;
}
return false;
}
/**
* Information on a Universal Module Definition A UMD is an IF statement and a reference to which
* branch contains the commonjs export
*/
static class UmdPattern {
final Node ifRoot;
final Node activeBranch;
UmdPattern(Node ifRoot, Node activeBranch) {
this.ifRoot = ifRoot;
this.activeBranch = activeBranch;
}
}
static class ExportInfo {
final Node node;
final Scope scope;
final boolean isInSupportedScope;
ExportInfo(Node node, Scope scope) {
this.node = node;
this.scope = scope;
Node disqualifyingParent =
NodeUtil.getEnclosingNode(
node, (n) -> n.isIf() || n.isHook() || n.isFunction() || n.isArrowFunction());
this.isInSupportedScope = disqualifyingParent == null;
}
}
private Node getBaseQualifiedNameNode(Node n) {
Node refParent = n;
while (refParent.getParent() != null && refParent.getParent().isQualifiedName()) {
refParent = refParent.getParent();
}
return refParent;
}
/**
* UMD modules are often wrapped in an IIFE for cases where they are used as scripts instead of
* modules. Remove the wrapper.
* @return Whether an IIFE wrapper was found and removed.
*/
private boolean removeIIFEWrapper(Node root) {
checkState(root.isScript());
Node n = root.getFirstChild();
// Sometimes scripts start with a semicolon for easy concatenation.
// Skip any empty statements from those
while (n != null && n.isEmpty()) {
n = n.getNext();
}
// An IIFE wrapper must be the only non-empty statement in the script,
// and it must be an expression statement.
if (n == null || !n.isExprResult() || n.getNext() != null) {
return false;
}
// Function expression can be forced with !, just skip !
// TODO(ChadKillingsworth):
// Expression could also be forced with: + - ~ void
// ! ~ void can be repeated any number of times
if (n != null && n.getFirstChild() != null && n.getFirstChild().isNot()) {
n = n.getFirstChild();
}
Node call = n.getFirstChild();
if (call == null || !call.isCall()) {
return false;
}
// Find the IIFE call and function nodes
Node fnc;
if (call.getFirstChild().isFunction()) {
fnc = n.getFirstFirstChild();
} else if (call.getFirstChild().isGetProp()
&& call.getFirstFirstChild().isFunction()
&& call.getFirstFirstChild().getNext().isString()
&& call.getFirstFirstChild().getNext().getString().equals("call")) {
fnc = call.getFirstFirstChild();
// We only support explicitly binding "this" to the parent "this" or "exports"
if (!(call.getSecondChild() != null
&& (call.getSecondChild().isThis()
|| call.getSecondChild().matchesQualifiedName(EXPORTS)))) {
return false;
}
} else {
return false;
}
if (NodeUtil.doesFunctionReferenceOwnArgumentsObject(fnc)) {
return false;
}
CompilerInput ci = compiler.getInput(root.getInputId());
ModulePath modulePath = ci.getPath();
if (modulePath == null) {
return false;
}
String iifeLabel = getModuleName(modulePath) + "_iifeWrapper";
FunctionToBlockMutator mutator =
new FunctionToBlockMutator(compiler, compiler.getUniqueNameIdSupplier());
Node block = mutator.mutateWithoutRenaming(iifeLabel, fnc, call, null, false, false);
root.removeChildren();
root.addChildrenToFront(block.removeChildren());
reportNestedScopesDeleted(fnc);
compiler.reportChangeToEnclosingScope(root);
return true;
}
/**
* For AMD wrappers, webpack adds a shim for the "module" variable. We need that to be a free var
* so we remove the shim.
*/
private void removeWebpackModuleShim(Node root) {
checkState(root.isScript());
Node n = root.getFirstChild();
// Sometimes scripts start with a semicolon for easy concatenation.
// Skip any empty statements from those
while (n != null && n.isEmpty()) {
n = n.getNext();
}
// An IIFE wrapper must be the only non-empty statement in the script,
// and it must be an expression statement.
if (n == null || !n.isExprResult() || n.getNext() != null) {
return;
}
Node call = n.getFirstChild();
if (call == null || !call.isCall()) {
return;
}
// Find the IIFE call and function nodes
Node callTarget = call.getFirstChild();
if (!callTarget.isFunction()) {
return;
}
Node fnc = callTarget;
Node params = NodeUtil.getFunctionParameters(fnc);
Node moduleParam = null;
Node param = params.getFirstChild();
int paramNumber = 0;
while (param != null) {
paramNumber++;
if (param.isName() && param.getString().equals(MODULE)) {
moduleParam = param;
break;
}
param = param.getNext();
}
if (moduleParam == null) {
return;
}
boolean isFreeCall = call.getBooleanProp(Node.FREE_CALL);
Node arg = call.getChildAtIndex(isFreeCall ? paramNumber : paramNumber + 1);
if (arg == null) {
return;
}
Node argCallTarget = arg.getFirstChild();
if (arg.isCall()
&& argCallTarget.isCall()
&& isCommonJsImport(argCallTarget)
&& argCallTarget.getNext().matchesName(MODULE)) {
String importPath = getCommonJsImportPath(argCallTarget);
ModulePath modulePath =
compiler
.getInput(root.getInputId())
.getPath()
.resolveJsModule(
importPath, arg.getSourceFileName(), arg.getLineno(), arg.getCharno());
if (modulePath == null) {
// The module loader will issue an error
return;
}
if (modulePath.toString().contains("/buildin/module.js")) {
arg.detach();
param.detach();
compiler.reportChangeToChangeScope(fnc);
compiler.reportChangeToEnclosingScope(fnc);
}
}
}
/**
* Traverse the script. Find all references to CommonJS require (import) and module.exports or
* export statements. Rewrites any require calls to reference the rewritten module name.
*/
class FindImportsAndExports implements NodeTraversal.Callback, ErrorHandler {
private boolean hasGoogProvideOrModule = false;
private Node script = null;
boolean isCommonJsModule() {
return (exports.size() > 0 || moduleExports.size() > 0) && !hasGoogProvideOrModule;
}
List umdPatterns = new ArrayList<>();
List moduleExports = new ArrayList<>();
List exports = new ArrayList<>();
List errors = new ArrayList<>();
@Override
public void report(CheckLevel ignoredLevel, JSError error) {
errors.add(error);
}
public List getModuleExports() {
return ImmutableList.copyOf(moduleExports);
}
public List getExports() {
return ImmutableList.copyOf(exports);
}
@Override
public boolean shouldTraverse(NodeTraversal nodeTraversal, Node n, Node parent) {
if (n.isScript()) {
checkState(this.script == null);
this.script = n;
}
return true;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// Check for goog.provide or goog.module statements
if (parent == null
|| NodeUtil.isControlStructure(parent)
|| NodeUtil.isStatementBlock(parent)) {
if (n.isExprResult()) {
Node maybeGetProp = n.getFirstFirstChild();
if (maybeGetProp != null
&& (maybeGetProp.matchesQualifiedName("goog.provide")
|| maybeGetProp.matchesQualifiedName("goog.module"))) {
hasGoogProvideOrModule = true;
}
}
}
// Find require.ensure calls
if (n.isCall() && n.getFirstChild().matchesQualifiedName("require.ensure")) {
visitRequireEnsureCall(t, n);
}
if (n.matchesQualifiedName(MODULE + "." + EXPORTS)
|| (n.isGetElem()
&& n.getFirstChild().matchesQualifiedName(MODULE)
&& n.getSecondChild().isString()
&& n.getSecondChild().getString().equals(EXPORTS))) {
if (isCommonJsExport(t, n)) {
moduleExports.add(new ExportInfo(n, t.getScope()));
// If the module.exports statement is nested in an if statement,
// and the test of the if checks for "module" or "define,
// assume the if statement is an UMD pattern with a common js export in the then branch
UmdTestInfo umdTestAncestor = getOutermostUmdTest(parent);
if (umdTestAncestor != null && !isInIfTest(n)) {
UmdPattern existingPattern = findUmdPattern(umdPatterns, umdTestAncestor.enclosingIf);
if (existingPattern == null) {
umdPatterns.add(
new UmdPattern(umdTestAncestor.enclosingIf, umdTestAncestor.activeBranch));
}
}
}
} else if (n.matchesQualifiedName("define.amd")
|| n.matchesQualifiedName("window.define.amd")) {
// If a define.amd statement is in the test of an if statement,
// and the statement has no "else" block, we simply want to remove
// the entire if statement.
UmdTestInfo umdTestAncestor = getOutermostUmdTest(parent);
if (umdTestAncestor != null && isInIfTest(n)) {
UmdPattern existingPattern = findUmdPattern(umdPatterns, umdTestAncestor.enclosingIf);
if (existingPattern == null && umdTestAncestor.enclosingIf.getChildAtIndex(2) == null) {
umdPatterns.add(new UmdPattern(umdTestAncestor.enclosingIf, null));
}
}
}
if (n.isName() && EXPORTS.equals(n.getString())) {
Var v = t.getScope().getVar(EXPORTS);
if (v == null || v.isGlobal()) {
Node qNameRoot = getBaseQualifiedNameNode(n);
if (qNameRoot != null
&& qNameRoot.matchesQualifiedName(EXPORTS)
&& NodeUtil.isLValue(qNameRoot)) {
// Match the special assignment
// exports = module.exports
if (n.getGrandparent().isExprResult()
&& n.getNext() != null
&& ((n.getNext().isGetProp()
&& n.getNext().matchesQualifiedName(MODULE + "." + EXPORTS))
|| (n.getNext().isAssign()
&& n.getNext()
.getFirstChild()
.matchesQualifiedName(MODULE + "." + EXPORTS)))) {
exports.add(new ExportInfo(n, t.getScope()));
// Ignore inlining created identity vars
// var exports = exports
} else if (!this.hasGoogProvideOrModule
&& (v == null
|| (v.getNameNode() == null && v.getNameNode().getFirstChild() != n))) {
errors.add(JSError.make(qNameRoot, SUSPICIOUS_EXPORTS_ASSIGNMENT));
}
} else {
exports.add(new ExportInfo(n, t.getScope()));
// If the exports statement is nested in the then branch of an if statement,
// and the test of the if checks for "module" or "define,
// assume the if statement is an UMD pattern with a common js export in the then branch
UmdTestInfo umdTestAncestor = getOutermostUmdTest(parent);
if (umdTestAncestor != null && !isInIfTest(n)) {
UmdPattern existingPattern = findUmdPattern(umdPatterns, umdTestAncestor.enclosingIf);
if (existingPattern == null) {
umdPatterns.add(
new UmdPattern(umdTestAncestor.enclosingIf, umdTestAncestor.activeBranch));
}
}
}
}
} else if (n.isThis() && n.getParent().isGetProp() && t.inGlobalScope()) {
exports.add(new ExportInfo(n, t.getScope()));
}
if (isCommonJsImport(n)) {
visitRequireCall(t, n, parent);
}
}
/** Visit require calls. */
private void visitRequireCall(NodeTraversal t, Node require, Node parent) {
// When require("name") is used as a standalone statement (the result isn't used)
// it indicates that a module is being loaded for the side effects it produces.
// In this case the require statement should just be removed as the dependency
// sorting will insert the file for us.
if (!NodeUtil.isExpressionResultUsed(require)
&& parent.isExprResult()
&& NodeUtil.isStatementBlock(parent.getParent())) {
// Attempt to resolve the module so that load warnings are issued
t.getInput()
.getPath()
.resolveJsModule(
getCommonJsImportPath(require),
require.getSourceFileName(),
require.getLineno(),
require.getCharno());
Node grandparent = parent.getParent();
parent.detach();
compiler.reportChangeToEnclosingScope(grandparent);
}
}
/**
* Visit require.ensure calls. Replace the call with an IIFE. Require.ensure must always be of
* the form:
*
* require.ensure(['module1', ...], function(require) {})
*/
private void visitRequireEnsureCall(NodeTraversal t, Node call) {
if (!call.hasXChildren(3)) {
compiler.report(
JSError.make(
call,
UNKNOWN_REQUIRE_ENSURE,
"Expected the function to have 2 arguments but instead found {0}",
"" + call.getChildCount()));
return;
}
Node dependencies = call.getSecondChild();
if (!dependencies.isArrayLit()) {
compiler.report(
JSError.make(
dependencies,
UNKNOWN_REQUIRE_ENSURE,
"The first argument must be an array literal of string literals."));
return;
}
for (Node dep : dependencies.children()) {
if (!dep.isString()) {
compiler.report(
JSError.make(
dep,
UNKNOWN_REQUIRE_ENSURE,
"The first argument must be an array literal of string literals."));
return;
}
}
Node callback = dependencies.getNext();
if (!(callback.isFunction()
&& callback.getSecondChild().hasOneChild()
&& callback.getSecondChild().getFirstChild().isName()
&& "require".equals(callback.getSecondChild().getFirstChild().getString()))) {
compiler.report(
JSError.make(
callback,
UNKNOWN_REQUIRE_ENSURE,
"The second argument must be a function"
+ " whose first argument is named \"require\"."));
return;
}
callback.detach();
// Remove the "require" argument from the parameter list.
callback.getSecondChild().removeChildren();
call.removeChildren();
call.putBooleanProp(Node.FREE_CALL, true);
call.addChildToFront(callback);
t.reportCodeChange();
}
void reportModuleErrors() {
for (JSError error : errors) {
compiler.report(error);
}
}
/**
* If the export is directly assigned more than once, or the assignments are not global, declare
* the module name variable.
*
*
If all of the assignments are simply property assignments, initialize the module name
* variable as a namespace.
*
*
Returns whether the default export can be declared constant
*/
boolean initializeModule() {
CompilerInput ci = compiler.getInput(this.script.getInputId());
ModulePath modulePath = ci.getPath();
if (modulePath == null) {
return true;
}
String moduleName = getModuleName(ci);
List exportsToRemove = new ArrayList<>();
for (ExportInfo export : exports) {
if (NodeUtil.getEnclosingScript(export.node) == null) {
exportsToRemove.add(export);
continue;
}
Node qNameBase = getBaseQualifiedNameNode(export.node);
if (export.node == qNameBase
&& export.node.getParent().isAssign()
&& export.node.getGrandparent().isExprResult()
&& export.node.getPrevious() == null
&& export.node.getNext() != null) {
// Find any identity assignments and just remove them
// exports = module.exports;
if (export.node.getNext().isGetProp()
&& export.node.getNext().matchesQualifiedName(MODULE + "." + EXPORTS)) {
for (ExportInfo moduleExport : moduleExports) {
if (moduleExport.node == export.node.getNext()) {
moduleExports.remove(moduleExport);
break;
}
}
Node changeRoot = export.node.getGrandparent().getParent();
export.node.getGrandparent().detach();
exportsToRemove.add(export);
compiler.reportChangeToEnclosingScope(changeRoot);
// Find compound identity assignments and remove the exports = portion
// exports = module.exports = foo;
} else if (export.node.getNext().isAssign()
&& export
.node
.getNext()
.getFirstChild()
.matchesQualifiedName(MODULE + "." + EXPORTS)) {
Node assign = export.node.getNext();
export.node.getParent().replaceWith(assign.detach());
exportsToRemove.add(export);
compiler.reportChangeToEnclosingScope(assign);
}
// Find babel transpiled interop assignment
// module.exports = exports['default'];
} else if (export.node.getParent().isGetElem()
&& export.node.getNext().isString()
&& export.node.getNext().getString().equals(EXPORT_PROPERTY_NAME)
&& export.node.getGrandparent().isAssign()
&& export.node.getParent().getPrevious() != null
&& export.node.getParent().getPrevious().matchesQualifiedName(MODULE + "." + EXPORTS)) {
Node parent = export.node.getParent();
Node grandparent = parent.getParent();
Node prop = export.node.getNext();
parent.replaceWith(
IR.getprop(export.node.detach(), prop.detach()).useSourceInfoFrom(parent));
compiler.reportChangeToEnclosingScope(grandparent);
}
}
exports.removeAll(exportsToRemove);
exportsToRemove.clear();
HashMap exportsToReplace = new HashMap<>();
for (ExportInfo export : moduleExports) {
if (NodeUtil.getEnclosingScript(export.node) == null) {
exportsToRemove.add(export);
} else if (export.node.isGetElem()) {
Node prop = export.node.getSecondChild().detach();
ExportInfo newExport =
new ExportInfo(IR.getprop(export.node.getFirstChild().detach(), prop), export.scope);
export.node.replaceWith(newExport.node);
compiler.reportChangeToEnclosingScope(newExport.node);
exportsToReplace.put(export, newExport);
}
}
moduleExports.removeAll(exportsToRemove);
for (ExportInfo oldExport : exportsToReplace.keySet()) {
int oldIndex = moduleExports.indexOf(oldExport);
moduleExports.remove(oldIndex);
moduleExports.add(oldIndex, exportsToReplace.get(oldExport));
}
// If we assign to the variable more than once or all the assignments
// are properties, initialize the variable as well.
int directAssignments = 0;
for (ExportInfo export : moduleExports) {
if (NodeUtil.getEnclosingScript(export.node) == null) {
continue;
}
Node base = getBaseQualifiedNameNode(export.node);
if (base == export.node && export.node.getParent().isAssign()) {
Node rValue = NodeUtil.getRValueOfLValue(export.node);
if (rValue == null || !rValue.isObjectLit()) {
directAssignments++;
} else if (rValue.isObjectLit()) {
for (Node key = rValue.getFirstChild(); key != null; key = key.getNext()) {
if ((!key.isStringKey() || key.isQuotedString()) && !key.isMemberFunctionDef()) {
directAssignments++;
break;
}
}
}
}
}
Node initModule = IR.var(IR.name(moduleName), IR.objectlit());
initModule.getFirstChild().putBooleanProp(Node.MODULE_EXPORT, true);
initModule.getFirstChild().makeNonIndexable();
JSDocInfoBuilder builder = new JSDocInfoBuilder(true);
builder.recordConstancy();
initModule.setJSDocInfo(builder.build());
if (directAssignments == 0 || (!exports.isEmpty() && !moduleExports.isEmpty())) {
Node defaultProp = IR.stringKey(EXPORT_PROPERTY_NAME);
defaultProp.putBooleanProp(Node.MODULE_EXPORT, true);
defaultProp.addChildToFront(IR.objectlit());
initModule.getFirstFirstChild().addChildToFront(defaultProp);
if (exports.isEmpty() || moduleExports.isEmpty()) {
builder = new JSDocInfoBuilder(true);
builder.recordConstancy();
defaultProp.setJSDocInfo(builder.build());
}
}
this.script.addChildToFront(initModule.useSourceInfoFromForTree(this.script));
compiler.reportChangeToEnclosingScope(this.script);
return directAssignments < 2 && (exports.isEmpty() || moduleExports.isEmpty());
}
private class UmdTestInfo {
public Node enclosingIf;
public Node activeBranch;
UmdTestInfo(Node enclosingIf, Node activeBranch) {
this.enclosingIf = enclosingIf;
this.activeBranch = activeBranch;
}
}
/**
* Find the outermost if node ancestor for a node without leaving the function scope. To match,
* the test class of the "if" statement must reference "module" or "define" names.
*/
private UmdTestInfo getOutermostUmdTest(Node n) {
if (n == null || NodeUtil.isTopLevel(n) || n.isFunction()) {
return null;
}
Node parent = n.getParent();
if (parent == null) {
return null;
}
// When walking up ternary operations (hook), don't check if parent is the condition,
// because one ternary operation can be then/else branch of another.
if ((parent.isIf() || parent.isHook())) {
UmdTestInfo umdTestInfo = getOutermostUmdTest(parent);
if (umdTestInfo != null) {
// If this is the then block of an else-if statement, set the active branch to the
// then block rather than the "if" itself.
if (parent.isIf()
&& parent.getSecondChild() == n
&& parent.getParent() != null
&& parent.getParent().isBlock()
&& parent.getNext() == null
&& umdTestInfo.activeBranch == parent.getParent()) {
return new UmdTestInfo(umdTestInfo.enclosingIf, n);
}
return umdTestInfo;
}
final List umdTests = new ArrayList<>();
NodeUtil.visitPreOrder(
parent.getFirstChild(),
new NodeUtil.Visitor() {
@Override
public void visit(Node node) {
if ((node.isName()
&& (node.getString().equals(MODULE) || node.getString().equals("define")))
|| (node.isGetProp() && node.matchesQualifiedName("window.define"))
|| (node.isString()
&& node.getString().equals("amd")
&& node.getParent().isIn())) {
umdTests.add(node);
}
}
});
// Webpack replaces tests of `typeof module !== 'undefined'` with `true`
if (umdTests.isEmpty() && parent.getFirstChild().isTrue()) {
umdTests.add(parent.getFirstChild());
}
if (!umdTests.isEmpty()) {
return new UmdTestInfo(parent, n);
}
return null;
}
return getOutermostUmdTest(parent);
}
/** Return whether the node is within the test portion of an if statement */
private boolean isInIfTest(Node n) {
if (n == null || NodeUtil.isTopLevel(n) || n.isFunction()) {
return false;
}
Node parent = n.getParent();
if (parent == null) {
return false;
}
if ((parent.isIf() || parent.isHook()) && parent.getFirstChild() == n) {
return true;
}
return isInIfTest(parent);
}
/** Remove a Universal Module Definition and leave just the commonjs export statement */
boolean replaceUmdPatterns() {
boolean needsRetraverse = false;
Node changeScope;
for (UmdPattern umdPattern : umdPatterns) {
if (NodeUtil.getEnclosingScript(umdPattern.ifRoot) == null) {
reportNestedScopesDeleted(umdPattern.ifRoot);
continue;
}
Node parent = umdPattern.ifRoot.getParent();
Node newNode = umdPattern.activeBranch;
if (newNode == null) {
parent.removeChild(umdPattern.ifRoot);
reportNestedScopesDeleted(umdPattern.ifRoot);
compiler.reportChangeToEnclosingScope(parent);
needsRetraverse = true;
continue;
}
// Remove redundant block node. Not strictly necessary, but makes tests more legible.
if (umdPattern.activeBranch.isBlock() && umdPattern.activeBranch.hasOneChild()) {
newNode = umdPattern.activeBranch.removeFirstChild();
} else {
newNode.detach();
}
needsRetraverse = true;
parent.replaceChild(umdPattern.ifRoot, newNode);
reportNestedScopesDeleted(umdPattern.ifRoot);
changeScope = NodeUtil.getEnclosingChangeScopeRoot(newNode);
if (changeScope != null) {
compiler.reportChangeToEnclosingScope(newNode);
}
Node block = parent;
if (block.isExprResult()) {
block = block.getParent();
}
// Detect UMD Factory Patterns and inline the functions
if (block.isBlock() && block.getParent().isFunction()
&& block.getGrandparent().isCall()
&& parent.hasOneChild()) {
Node enclosingFnCall = block.getGrandparent();
Node fn = block.getParent();
Node enclosingScript = NodeUtil.getEnclosingScript(enclosingFnCall);
if (enclosingScript == null) {
continue;
}
CompilerInput ci = compiler.getInput(
NodeUtil.getEnclosingScript(enclosingFnCall).getInputId());
ModulePath modulePath = ci.getPath();
if (modulePath == null) {
continue;
}
needsRetraverse = true;
String factoryLabel =
modulePath.toModuleName() + "_factory" + compiler.getUniqueNameIdSupplier().get();
FunctionToBlockMutator mutator =
new FunctionToBlockMutator(compiler, compiler.getUniqueNameIdSupplier());
Node newStatements =
mutator.mutateWithoutRenaming(factoryLabel, fn, enclosingFnCall, null, false, false);
// Check to see if the returned block is of the form:
// {
// var jscomp$inline = function() {};
// jscomp$inline();
// }
//
// or
//
// {
// var jscomp$inline = function() {};
// module.exports = jscomp$inline();
// }
//
// If so, inline again
if (newStatements.isBlock()
&& newStatements.hasTwoChildren()
&& newStatements.getFirstChild().isVar()
&& newStatements.getFirstFirstChild().hasOneChild()
&& newStatements.getFirstFirstChild().getFirstChild().isFunction()
&& newStatements.getSecondChild().isExprResult()) {
Node inlinedFn = newStatements.getFirstFirstChild().getFirstChild();
Node expr = newStatements.getSecondChild().getFirstChild();
Node call = null;
String assignedName = null;
if (expr.isAssign() && expr.getSecondChild().isCall()) {
call = expr.getSecondChild();
assignedName =
modulePath.toModuleName() + "_iife" + compiler.getUniqueNameIdSupplier().get();
} else if (expr.isCall()) {
call = expr;
}
if (call != null) {
newStatements =
mutator.mutateWithoutRenaming(
factoryLabel, inlinedFn, call, assignedName, false, false);
if (assignedName != null) {
Node newName =
IR.var(
NodeUtil.newName(
compiler,
assignedName,
fn,
expr.getFirstChild().getQualifiedName()))
.useSourceInfoFromForTree(fn);
if (newStatements.hasChildren()
&& newStatements.getFirstChild().isExprResult()
&& newStatements.getFirstFirstChild().isAssign()
&& newStatements.getFirstFirstChild().getFirstChild().isName()
&& newStatements
.getFirstFirstChild()
.getFirstChild()
.getString()
.equals(assignedName)) {
newName
.getFirstChild()
.addChildToFront(
newStatements.getFirstFirstChild().getSecondChild().detach());
newStatements.replaceChild(newStatements.getFirstChild(), newName);
} else {
newStatements.addChildToFront(newName);
}
expr.replaceChild(expr.getSecondChild(), newName.getFirstChild().cloneNode());
newStatements.addChildToBack(expr.getParent().detach());
}
}
}
Node callRoot = enclosingFnCall.getParent();
if (callRoot.isNot()) {
callRoot = callRoot.getParent();
}
if (callRoot.isExprResult()) {
Node callRootParent = callRoot.getParent();
callRootParent.addChildrenAfter(newStatements.removeChildren(), callRoot);
callRoot.detach();
reportNestedScopesChanged(callRootParent);
compiler.reportChangeToEnclosingScope(callRootParent);
reportNestedScopesDeleted(enclosingFnCall);
} else {
parent.replaceChild(umdPattern.ifRoot, newNode);
compiler.reportChangeToEnclosingScope(newNode);
reportNestedScopesDeleted(umdPattern.ifRoot);
}
}
}
return needsRetraverse;
}
}
private void reportNestedScopesDeleted(Node n) {
NodeUtil.visitPreOrder(
n,
new NodeUtil.Visitor() {
@Override
public void visit(Node n) {
if (n.isFunction()) {
compiler.reportFunctionDeleted(n);
}
}
});
}
private void reportNestedScopesChanged(Node n) {
NodeUtil.visitPreOrder(
n,
new NodeUtil.Visitor() {
@Override
public void visit(Node n) {
if (n.isFunction()) {
compiler.reportChangeToChangeScope(n);
}
}
});
}
private static UmdPattern findUmdPattern(List umdPatterns, Node n) {
for (UmdPattern umd : umdPatterns) {
if (umd.ifRoot == n) {
return umd;
}
}
return null;
}
/**
* Traverse a file and rewrite all references to imported names directly to the targeted module
* name.
*
* If a file is a CommonJS module, rewrite export statements. Typically exports create an alias
* - the rewriting tries to avoid such aliases.
*/
private class RewriteModule extends AbstractPostOrderCallback {
private final boolean allowFullRewrite;
private final ImmutableCollection exports;
private final List imports = new ArrayList<>();
private final List rewrittenClassExpressions = new ArrayList<>();
private final List functionsToHoist = new ArrayList<>();
private final boolean defaultExportIsConst;
public RewriteModule(
boolean allowFullRewrite,
ImmutableCollection exports,
boolean defaultExportIsConst) {
this.allowFullRewrite = allowFullRewrite;
this.exports = exports;
this.defaultExportIsConst = defaultExportIsConst;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
switch (n.getToken()) {
case SCRIPT:
// Class names can't be changed during the middle of a traversal. Unlike functions,
// the name can be the EMPTY token rather than just a zero length string.
for (Node clazz : rewrittenClassExpressions) {
clazz.replaceChild(
clazz.getFirstChild(), IR.empty().useSourceInfoFrom(clazz.getFirstChild()));
t.reportCodeChange();
}
CompilerInput ci = compiler.getInput(n.getInputId());
String moduleName = getModuleName(ci);
// If a function is the direct module export, move it to the top.
for (int i = 1; i < functionsToHoist.size(); i++) {
if (functionsToHoist
.get(i)
.getFirstFirstChild()
.matchesQualifiedName(getBasePropertyImport(moduleName))) {
Node fncVar = functionsToHoist.get(i);
functionsToHoist.remove(i);
functionsToHoist.add(0, fncVar);
break;
}
}
// Hoist functions in reverse order so that they maintain the same relative
// order after hoisting.
for (int i = functionsToHoist.size() - 1; i >= 0; i--) {
Node functionExpr = functionsToHoist.get(i);
Node scopeRoot = t.getClosestHoistScopeRoot();
Node insertionPoint = scopeRoot.getFirstChild();
if (insertionPoint == null
|| !(insertionPoint.isVar()
&& insertionPoint.getFirstChild().getString().equals(moduleName))) {
insertionPoint = null;
}
if (insertionPoint == null) {
if (scopeRoot.getFirstChild() != functionExpr) {
scopeRoot.addChildToFront(functionExpr.detach());
}
} else if (insertionPoint != functionExpr && insertionPoint.getNext() != functionExpr) {
scopeRoot.addChildAfter(functionExpr.detach(), insertionPoint);
}
}
for (ExportInfo export : exports) {
visitExport(t, export);
}
for (Node require : imports) {
visitRequireCall(t, require, require.getParent());
}
break;
case CALL:
if (isCommonJsImport(n)) {
imports.add(n);
}
break;
case VAR:
case LET:
case CONST:
// Multiple declarations need split apart so that they can be refactored into
// property assignments or removed altogether. Don't split declarations for
// ES module export calls as it breaks AST and ES modules shouldn't be affected at all
// by this pass.
if (n.hasMoreThanOneChild() && !NodeUtil.isAnyFor(parent) && !parent.isExport()) {
List vars = splitMultipleDeclarations(n);
t.reportCodeChange();
for (Node var : vars) {
visit(t, var.getFirstChild(), var);
}
}
// UMD Inlining can shadow global variables - these are just removed.
//
// var exports = exports;
if (n.getFirstChild().hasChildren()
&& n.getFirstFirstChild().isName()
&& n.getFirstChild().getString().equals(n.getFirstFirstChild().getString())) {
n.detach();
t.reportCodeChange();
return;
}
break;
case NAME:
{
// If this is a name declaration with multiple names, it will be split apart when
// the parent is visited and then revisit the children.
if (NodeUtil.isNameDeclaration(n.getParent())
&& n.getParent().hasMoreThanOneChild()
&& !NodeUtil.isAnyFor(n.getGrandparent())) {
break;
}
String qName = n.getQualifiedName();
if (qName == null) {
break;
}
final Var nameDeclaration = t.getScope().getVar(qName);
if (nameDeclaration != null) {
if (NodeUtil.isLhsByDestructuring(n)) {
maybeUpdateName(t, n, nameDeclaration);
} else if (nameDeclaration.getNode() != null
&& Objects.equals(nameDeclaration.getNode().getInputId(), n.getInputId())) {
// Avoid renaming a shadowed global
//
// var angular = angular; // value is global ref
Node enclosingDeclaration =
NodeUtil.getEnclosingNode(
n,
new Predicate() {
@Override
public boolean apply(Node node) {
return node == nameDeclaration.getNameNode();
}
});
if (enclosingDeclaration == null
|| enclosingDeclaration == n
|| nameDeclaration.getScope() != t.getScope()) {
maybeUpdateName(t, n, nameDeclaration);
}
}
// Replace loose "module" references with an object literal
} else if (allowFullRewrite
&& n.getString().equals(MODULE)
&& !(n.getParent().isGetProp()
|| n.getParent().isGetElem()
|| n.getParent().isTypeOf())) {
Node objectLit = IR.objectlit().useSourceInfoFrom(n);
n.replaceWith(objectLit);
t.reportCodeChange(objectLit);
}
break;
}
// ES6 object literal shorthand notation can refer to renamed variables
case STRING_KEY:
{
if (n.hasChildren() || n.isQuotedString() || NodeUtil.isLhsByDestructuring(n)) {
break;
}
Var nameDeclaration = t.getScope().getVar(n.getString());
if (nameDeclaration == null) {
break;
}
String importedName = getModuleImportName(t, nameDeclaration.getNode());
if (nameDeclaration.isGlobal() || importedName != null) {
Node value = IR.name(n.getString()).useSourceInfoFrom(n);
n.addChildToBack(value);
maybeUpdateName(t, value, nameDeclaration);
}
break;
}
case GETPROP:
if (n.matchesQualifiedName(MODULE + ".id")
|| n.matchesQualifiedName(MODULE + ".filename")) {
Var v = t.getScope().getVar(MODULE);
if (v == null || v.isExtern()) {
n.replaceWith(IR.string(t.getInput().getPath().toString()).useSourceInfoFrom(n));
}
} else if (allowFullRewrite
&& n.getFirstChild().isName()
&& n.getFirstChild().getString().equals(MODULE)
&& !n.matchesQualifiedName(MODULE + "." + EXPORTS)) {
Var v = t.getScope().getVar(MODULE);
if (v == null || v.isExtern()) {
n.getFirstChild().replaceWith(IR.objectlit().useSourceInfoFrom(n.getFirstChild()));
}
}
break;
case TYPEOF:
if (allowFullRewrite
&& n.getFirstChild().isName()
&& (n.getFirstChild().getString().equals(MODULE)
|| n.getFirstChild().getString().equals(EXPORTS))) {
Var v = t.getScope().getVar(n.getFirstChild().getString());
if (v == null || v.isExtern()) {
n.replaceWith(IR.string("object"));
}
}
break;
default:
break;
}
fixTypeAnnotationsForNode(t, n);
}
private void fixTypeAnnotationsForNode(NodeTraversal t, Node n) {
JSDocInfo info = n.getJSDocInfo();
if (info != null) {
for (Node typeNode : info.getTypeNodes()) {
fixTypeNode(t, typeNode);
}
}
}
/**
* Visit require calls. Rewrite require statements to be a direct reference to name of require
* module. By this point all references to the import alias should have already been renamed.
*/
private void visitRequireCall(NodeTraversal t, Node require, Node parent) {
String moduleName = getImportedModuleName(t, require);
Node moduleRef =
NodeUtil.newQName(compiler, getBasePropertyImport(moduleName, require))
.useSourceInfoFromForTree(require.getSecondChild());
parent.replaceChild(require, moduleRef);
t.reportCodeChange();
}
/**
* Visit export statements. Export statements can be either a direct assignment: module.exports
* = foo or a property assignment: module.exports.foo = foo; exports.foo = foo;
*/
private void visitExport(NodeTraversal t, ExportInfo export) {
Node root = getBaseQualifiedNameNode(export.node);
Node rValue = NodeUtil.getRValueOfLValue(root);
// For object literal assignments to module.exports, convert them to
// individual property assignments.
//
// module.exports = { foo: bar};
//
// becomes
//
// module.exports = {};
// module.exports.foo = bar;
if (root.matchesQualifiedName("module.exports")) {
if (rValue != null
&& rValue.isObjectLit()
&& root.getParent().isAssign()
&& root.getParent().getParent().isExprResult()) {
if (expandObjectLitAssignment(t, root, export.scope)) {
return;
}
}
}
String moduleName = getModuleName(t.getInput());
Var moduleInitialization = t.getScope().getVar(moduleName);
// If this is an assignment to module.exports or exports, renaming
// has already handled this case. Remove the export.
Var rValueVar = null;
if (rValue != null && rValue.isQualifiedName()) {
rValueVar = export.scope.getVar(rValue.getQualifiedName());
}
if (root.getParent().isAssign()
&& root.getGrandparent().isExprResult()
&& (root.getNext() != null && (root.getNext().isName() || root.getNext().isGetProp()))
&& root.getParent().getParent().isExprResult()
&& rValueVar != null
&& (NodeUtil.getEnclosingScript(rValueVar.nameNode) == null
|| (rValueVar.nameNode.getParent() != null && !rValueVar.isParam()))
&& export.isInSupportedScope
&& (rValueVar.getNameNode().getParent() == null
|| !NodeUtil.isLhsByDestructuring(rValueVar.getNameNode()))) {
root.getParent().getParent().detach();
t.reportCodeChange();
return;
}
moduleName = moduleName + "." + EXPORT_PROPERTY_NAME;
Node updatedExport =
NodeUtil.newQName(compiler, moduleName, export.node, export.node.getQualifiedName());
updatedExport.putBooleanProp(Node.MODULE_EXPORT, true);
boolean exportIsConst =
defaultExportIsConst
&& updatedExport.matchesQualifiedName(
getBasePropertyImport(getModuleName(t.getInput())))
&& root == export.node
&& NodeUtil.isLValue(export.node);
Node changeScope = null;
if (root.matchesQualifiedName("module.exports")
&& rValue != null
&& export.scope.getVar("module.exports") == null
&& root.getParent().isAssign()
&& root.getGrandparent().isExprResult()
&& moduleInitialization == null) {
// Rewrite "module.exports = foo;" to "var moduleName = {default: foo};"
Node parent = root.getParent();
Node exportName = IR.exprResult(IR.assign(updatedExport, rValue.detach()));
if (exportIsConst) {
JSDocInfoBuilder info = new JSDocInfoBuilder(false);
info.recordConstancy();
exportName.getFirstChild().setJSDocInfo(info.build());
}
parent.getParent().replaceWith(exportName.useSourceInfoFromForTree(root.getParent()));
changeScope = NodeUtil.getEnclosingChangeScopeRoot(parent);
} else if (root.getNext() != null
&& root.getNext().isName()
&& rValueVar != null
&& rValueVar.isGlobal()
&& export.isInSupportedScope
&& (rValueVar.getNameNode().getParent() == null
|| !NodeUtil.isLhsByDestructuring(rValueVar.getNameNode()))) {
// This is a where a module export assignment is used in a complex expression.
// Before: `SOME_VALUE !== undefined && module.exports = SOME_VALUE`
// After: `SOME_VALUE !== undefined && module$name`
Node parent = root.getParent();
root.detach();
parent.replaceWith(root);
if (root == export.node) {
root = updatedExport;
}
export.node.replaceWith(updatedExport);
changeScope = NodeUtil.getEnclosingChangeScopeRoot(root);
} else {
// Other references to "module.exports" are just replaced with the module name.
export.node.replaceWith(updatedExport);
if (updatedExport.getParent().isAssign() && exportIsConst) {
JSDocInfoBuilder infoBuilder =
JSDocInfoBuilder.maybeCopyFrom(updatedExport.getParent().getJSDocInfo());
infoBuilder.recordConstancy();
updatedExport.getParent().setJSDocInfo(infoBuilder.build());
}
changeScope = NodeUtil.getEnclosingChangeScopeRoot(updatedExport);
}
if (changeScope != null) {
compiler.reportChangeToChangeScope(changeScope);
}
}
/**
* Since CommonJS modules may have only a single export, it's common to see the export be an
* object pattern. We want to expand this to individual property assignments. If any individual
* property assignment has been renamed, it will be removed.
*
* We need to keep assignments which aren't names
*
*
module.exports = { foo: bar, baz: function() {} }
*
*
becomes
*
*
module.exports.foo = bar; // removed later module.exports.baz = function() {};
*/
private boolean expandObjectLitAssignment(NodeTraversal t, Node export, Scope scope) {
checkState(export.getParent().isAssign());
Node insertionRef = export.getParent().getParent();
checkState(insertionRef.isExprResult());
Node insertionParent = insertionRef.getParent();
checkNotNull(insertionParent);
Node rValue = NodeUtil.getRValueOfLValue(export);
Node key = rValue.getFirstChild();
boolean removedNodes = false;
while (key != null) {
Node lhs;
if ((!key.isStringKey() || key.isQuotedString()) && !key.isMemberFunctionDef()) {
key = key.getNext();
continue;
}
lhs = IR.getprop(export.cloneTree(), IR.string(key.getString()));
Node value = null;
if (key.isStringKey()) {
if (key.hasChildren()) {
value = key.removeFirstChild();
} else {
value = IR.name(key.getString());
}
} else if (key.isMemberFunctionDef()) {
value = key.getFirstChild().detach();
}
Node expr = null;
expr = IR.exprResult(IR.assign(lhs, value)).useSourceInfoIfMissingFromForTree(key);
insertionParent.addChildAfter(expr, insertionRef);
ExportInfo newExport = new ExportInfo(lhs.getFirstChild(), scope);
visitExport(t, newExport);
// Export statements can be removed in visitExport
if (expr != null && expr.getParent() != null) {
insertionRef = expr;
}
Node currentKey = key;
key = key.getNext();
currentKey.detach();
removedNodes = true;
}
if (!rValue.hasChildren()) {
export.getGrandparent().detach();
return true;
}
if (removedNodes) {
t.reportCodeChange(rValue);
}
return false;
}
/**
* Given a name reference, check to see if it needs renamed.
*
*
We handle 3 main cases: 1. References to an import alias. These are replaced with a direct
* reference to the imported module. 2. Names which are exported. These are rewritten to be the
* export assignment directly. 3. Global names: If a name is global to the script, add a suffix
* so it doesn't collide with any other global.
*
*
Rewriting case 1 is safe to perform on all files. Cases 2 and 3 can only be done if this
* file is a commonjs module.
*/
private void maybeUpdateName(NodeTraversal t, Node n, Var var) {
checkNotNull(var);
checkState(n.isName() || n.isGetProp());
checkState(n.getParent() != null);
String importedModuleName = getModuleImportName(t, var.getNode());
String name = n.getQualifiedName();
// Check if the name refers to a alias for a require('foo') import.
if (importedModuleName != null && n != var.getNode()) {
// Reference the imported name directly, rather than the alias
updateNameReference(t, n, name, importedModuleName, false, false);
} else if (allowFullRewrite) {
String exportedName = getExportedName(t, n, var);
// We need to exclude the alias created by the require import. We assume dead
// code elimination will remove these later.
if ((n != var.getNode() || n.getParent().isClass())
&& exportedName == null
&& (var == null
|| var.getNameNode().getParent() == null
|| !NodeUtil.isLhsByDestructuring(var.getNameNode()))) {
// The name is actually the export reference itself.
// This will be handled later by visitExports.
if (n.getParent().isClass() && n.getParent().getFirstChild() == n) {
rewrittenClassExpressions.add(n.getParent());
}
return;
}
// Check if the name is used as an export
if (importedModuleName == null
&& exportedName != null
&& !exportedName.equals(name)
&& !var.isParam()
&& (var.getNameNode().getParent() == null
|| !NodeUtil.isLhsByDestructuring(var.getNameNode()))) {
boolean exportPropIsConst =
defaultExportIsConst
&& getBasePropertyImport(getModuleName(t.getInput())).equals(exportedName)
&& getBaseQualifiedNameNode(n) == n
&& NodeUtil.isLValue(n);
updateNameReference(t, n, name, exportedName, true, exportPropIsConst);
// If it's a global name, rename it to prevent conflicts with other scripts
} else if (var.isGlobal()) {
String currentModuleName = getModuleName(t.getInput());
if (currentModuleName.equals(name)) {
return;
}
// refs to 'exports' are handled separately.
if (EXPORTS.equals(name)) {
return;
}
// closure_test_suite looks for test*() functions
if (compiler.getOptions().exportTestFunctions && currentModuleName.startsWith("test")) {
return;
}
String newName = name + "$$" + currentModuleName;
updateNameReference(t, n, name, newName, false, false);
}
}
}
/**
* @param nameRef the qualified name node
* @param originalName of nameRef
* @param newName for nameRef
* @param requireFunctionExpressions Whether named class or functions should be rewritten to
* variable assignments
*/
private void updateNameReference(
NodeTraversal t,
Node nameRef,
String originalName,
String newName,
boolean requireFunctionExpressions,
boolean qualifiedNameIsConst) {
Node parent = nameRef.getParent();
checkNotNull(parent);
checkNotNull(newName);
boolean newNameIsQualified = newName.indexOf('.') >= 0;
boolean newNameIsModuleExport =
newName.equals(getBasePropertyImport(getModuleName(t.getInput())));
Var newNameDeclaration = t.getScope().getVar(newName);
switch (parent.getToken()) {
case CLASS:
if (parent.getIndexOfChild(nameRef) == 0
&& (newNameIsQualified || requireFunctionExpressions)) {
// Refactor a named class to a class expression
// We can't remove the class name during a traversal, so save it for later
rewrittenClassExpressions.add(parent);
Node newNameRef = NodeUtil.newQName(compiler, newName, nameRef, originalName);
if (newNameIsModuleExport) {
newNameRef.putBooleanProp(Node.MODULE_EXPORT, true);
}
Node grandparent = parent.getParent();
Node expr;
if (!newNameIsQualified && newNameDeclaration == null) {
expr = IR.let(newNameRef, IR.nullNode()).useSourceInfoIfMissingFromForTree(nameRef);
} else {
expr =
IR.exprResult(IR.assign(newNameRef, IR.nullNode()))
.useSourceInfoIfMissingFromForTree(nameRef);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(parent.getJSDocInfo());
parent.setJSDocInfo(null);
if (qualifiedNameIsConst) {
info.recordConstancy();
}
expr.getFirstChild().setJSDocInfo(info.build());
fixTypeAnnotationsForNode(t, expr.getFirstChild());
}
grandparent.replaceChild(parent, expr);
if (expr.isLet()) {
expr.getFirstChild().replaceChild(expr.getFirstFirstChild(), parent);
} else {
expr.getFirstChild().replaceChild(expr.getFirstChild().getSecondChild(), parent);
}
} else if (parent.getIndexOfChild(nameRef) == 1) {
Node newNameRef = NodeUtil.newQName(compiler, newName, nameRef, originalName);
if (newNameIsModuleExport) {
newNameRef.putBooleanProp(Node.MODULE_EXPORT, true);
}
parent.replaceChild(nameRef, newNameRef);
} else {
nameRef.setString(newName);
nameRef.setOriginalName(originalName);
}
break;
case FUNCTION:
if (newNameIsQualified || requireFunctionExpressions) {
// Refactor a named function to a function expression
if (NodeUtil.isFunctionExpression(parent)) {
// Don't refactor if the parent is a named function expression.
// e.g. var foo = function foo() {};
return;
}
Node newNameRef = NodeUtil.newQName(compiler, newName, nameRef, originalName);
if (newNameIsModuleExport) {
newNameRef.putBooleanProp(Node.MODULE_EXPORT, true);
}
Node grandparent = parent.getParent();
nameRef.setString("");
Node expr;
if (!newNameIsQualified && newNameDeclaration == null) {
expr = IR.var(newNameRef, IR.nullNode()).useSourceInfoIfMissingFromForTree(nameRef);
} else {
expr =
IR.exprResult(IR.assign(newNameRef, IR.nullNode()))
.useSourceInfoIfMissingFromForTree(nameRef);
}
grandparent.replaceChild(parent, expr);
if (expr.isVar()) {
expr.getFirstChild().replaceChild(expr.getFirstFirstChild(), parent);
} else {
expr.getFirstChild().replaceChild(expr.getFirstChild().getSecondChild(), parent);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(parent.getJSDocInfo());
parent.setJSDocInfo(null);
if (qualifiedNameIsConst) {
info.recordConstancy();
}
expr.getFirstChild().setJSDocInfo(info.build());
fixTypeAnnotationsForNode(t, expr.getFirstChild());
}
functionsToHoist.add(expr);
} else {
nameRef.setString(newName);
nameRef.setOriginalName(originalName);
}
break;
case VAR:
case LET:
case CONST:
// Multiple declaration - needs split apart.
if (parent.hasMoreThanOneChild() && !NodeUtil.isAnyFor(parent.getParent())) {
splitMultipleDeclarations(parent);
parent = nameRef.getParent();
newNameDeclaration = t.getScope().getVar(newName);
}
if (newNameIsQualified) {
// Var declarations without initialization can simply
// be removed if they are being converted to a property.
if (!nameRef.hasChildren() && parent.getJSDocInfo() == null) {
parent.detach();
break;
}
// Refactor a var declaration to a getprop assignment
Node getProp = NodeUtil.newQName(compiler, newName, nameRef, originalName);
if (newNameIsModuleExport) {
getProp.putBooleanProp(Node.MODULE_EXPORT, true);
}
JSDocInfo info = parent.getJSDocInfo();
parent.setJSDocInfo(null);
if (nameRef.hasChildren()) {
Node assign = IR.assign(getProp, nameRef.removeFirstChild());
assign.setJSDocInfo(info);
Node expr = IR.exprResult(assign).useSourceInfoIfMissingFromForTree(nameRef);
parent.replaceWith(expr);
JSDocInfoBuilder infoBuilder = JSDocInfoBuilder.maybeCopyFrom(info);
parent.setJSDocInfo(null);
if (qualifiedNameIsConst) {
infoBuilder.recordConstancy();
}
assign.setJSDocInfo(infoBuilder.build());
fixTypeAnnotationsForNode(t, assign);
} else {
getProp.setJSDocInfo(info);
parent.replaceWith(IR.exprResult(getProp).useSourceInfoFrom(getProp));
}
} else if (newNameDeclaration != null && newNameDeclaration.getNameNode() != nameRef) {
// Variable is already defined. Convert this to an assignment.
// If the variable declaration has no initialization, we simply
// remove the node. This can occur when the variable which is exported
// is declared in an outer scope but assigned in an inner one.
if (!nameRef.hasChildren()) {
parent.detachFromParent();
break;
}
Node name = NodeUtil.newName(compiler, newName, nameRef, originalName);
Node assign = IR.assign(name, nameRef.removeFirstChild());
JSDocInfo info = parent.getJSDocInfo();
if (info != null) {
parent.setJSDocInfo(null);
assign.setJSDocInfo(info);
}
parent.replaceWith(IR.exprResult(assign).useSourceInfoFromForTree(nameRef));
} else {
nameRef.setString(newName);
nameRef.setOriginalName(originalName);
}
break;
default:
// Whenever possible, reuse the existing reference
if (!newNameIsQualified && nameRef.isName()) {
nameRef.setString(newName);
nameRef.setOriginalName(originalName);
} else {
Node name =
newNameIsQualified
? NodeUtil.newQName(compiler, newName, nameRef, originalName)
: NodeUtil.newName(compiler, newName, nameRef, originalName);
if (newNameIsModuleExport) {
name.putBooleanProp(Node.MODULE_EXPORT, true);
}
JSDocInfo info = nameRef.getJSDocInfo();
if (info != null) {
nameRef.setJSDocInfo(null);
name.setJSDocInfo(info);
}
name.useSourceInfoFromForTree(nameRef);
parent.replaceChild(nameRef, name);
if (nameRef.hasChildren()) {
name.addChildrenToFront(nameRef.removeChildren());
}
}
break;
}
t.reportCodeChange();
}
/**
* Determine whether the given name Node n is referenced in an export
*
* @return string - If the name is not used in an export, return it's own name If the name node
* is actually the export target itself, return null;
*/
private String getExportedName(NodeTraversal t, Node n, Var var) {
if (var == null || !Objects.equals(var.getNode().getInputId(), n.getInputId())) {
return n.getQualifiedName();
}
String baseExportName = getBasePropertyImport(getModuleName(t.getInput()));
for (ExportInfo export : this.exports) {
Node exportBase = getBaseQualifiedNameNode(export.node);
Node exportRValue = NodeUtil.getRValueOfLValue(exportBase);
if (exportRValue == null) {
continue;
}
Node exportedName = getExportedNameNode(export);
// We don't want to handle the export itself
if (export.isInSupportedScope
&& (exportRValue == n
|| ((NodeUtil.isClassExpression(exportRValue)
|| NodeUtil.isFunctionExpression(exportRValue))
&& exportedName == n))) {
return null;
}
String exportBaseQName = exportBase.getQualifiedName();
if (exportRValue.isObjectLit()) {
if (!"module.exports".equals(exportBaseQName)) {
return n.getQualifiedName();
}
Node key = exportRValue.getFirstChild();
boolean keyIsExport = false;
while (key != null) {
if (key.isStringKey()
&& !key.isQuotedString()
&& NodeUtil.isValidPropertyName(
compiler.getOptions().getLanguageIn().toFeatureSet(), key.getString())) {
if (key.hasChildren()) {
if (key.getFirstChild().isQualifiedName()) {
if (key.getFirstChild() == n) {
return null;
}
Var valVar = t.getScope().getVar(key.getFirstChild().getQualifiedName());
if (valVar != null && valVar.getNameNode() == var.getNameNode()) {
keyIsExport = true;
break;
}
}
} else {
if (key == n) {
return null;
}
// Handle ES6 object lit shorthand assignments
Var valVar = t.getScope().getVar(key.getString());
if (valVar != null && valVar.getNameNode() == var.getNameNode()) {
keyIsExport = true;
break;
}
}
}
key = key.getNext();
}
if (key != null && keyIsExport) {
if (export.isInSupportedScope) {
return baseExportName + "." + key.getString();
} else {
return n.getQualifiedName();
}
}
} else {
if (!export.isInSupportedScope) {
return n.getQualifiedName();
}
if (var.getNameNode() == exportedName) {
String exportPrefix;
if (exportBaseQName.startsWith(MODULE)) {
exportPrefix = MODULE + "." + EXPORTS;
} else {
exportPrefix = EXPORTS;
}
if (exportBaseQName.length() == exportPrefix.length()) {
return baseExportName;
}
return baseExportName + exportBaseQName.substring(exportPrefix.length());
}
}
}
return n.getQualifiedName();
}
private Node getExportedNameNode(ExportInfo info) {
Node qNameBase = getBaseQualifiedNameNode(info.node);
Node rValue = NodeUtil.getRValueOfLValue(qNameBase);
if (rValue == null) {
return null;
}
if (NodeUtil.isFunctionExpression(rValue)) {
return rValue.getFirstChild();
}
if (NodeUtil.isClassExpression(rValue) && rValue.getFirstChild() == qNameBase) {
return rValue.getFirstChild();
}
if (!rValue.isName()) {
return null;
}
Var var = info.scope.getVar(rValue.getString());
if (var == null) {
return null;
}
return var.getNameNode();
}
/**
* Determine if the given Node n is an alias created by a module import.
*
* @return null if it's not an alias or the imported module name
*/
private String getModuleImportName(NodeTraversal t, Node n) {
Node rValue = null;
String propSuffix = "";
Node parent = n.getParent();
if (parent != null && parent.isStringKey()) {
Node grandparent = parent.getParent();
if (grandparent.isObjectPattern() && grandparent.getParent().isDestructuringLhs()) {
rValue = grandparent.getNext();
propSuffix = "." + parent.getString();
}
}
if (propSuffix.isEmpty() && parent != null) {
rValue = NodeUtil.getRValueOfLValue(n);
}
if (rValue == null) {
return null;
}
if (rValue.isCall() && isCommonJsImport(rValue)) {
return getBasePropertyImport(getImportedModuleName(t, rValue), rValue) + propSuffix;
} else if (rValue.isGetProp() && isCommonJsImport(rValue.getFirstChild())) {
// var foo = require('bar').foo;
String importName =
getBasePropertyImport(
getImportedModuleName(t, rValue.getFirstChild()), rValue.getFirstChild());
String suffix =
rValue.getSecondChild().isGetProp()
? rValue.getSecondChild().getQualifiedName()
: rValue.getSecondChild().getString();
return importName + "." + suffix + propSuffix;
}
return null;
}
/**
* Update any type references in JSDoc annotations to account for all the rewriting we've done.
*/
private void fixTypeNode(NodeTraversal t, Node typeNode) {
if (typeNode.isString()) {
String name = typeNode.getString();
// Type nodes can be module paths.
if (ModuleLoader.isPathIdentifier(name)) {
int lastSlash = name.lastIndexOf('/');
int endIndex = name.indexOf('.', lastSlash);
String localTypeName = null;
if (endIndex == -1) {
endIndex = name.length();
} else {
localTypeName = name.substring(endIndex);
}
String moduleName = name.substring(0, endIndex);
String globalModuleName = getImportedModuleName(t, typeNode, moduleName);
String baseImportProperty = getBasePropertyImport(globalModuleName);
typeNode.setString(
localTypeName == null ? baseImportProperty : baseImportProperty + localTypeName);
} else {
// A type node can be a getprop. Any portion of the getprop
// can be either an import alias or export alias. Check each
// segment.
boolean wasRewritten = false;
int endIndex = -1;
while (endIndex < name.length()) {
endIndex = name.indexOf('.', endIndex + 1);
if (endIndex == -1) {
endIndex = name.length();
}
String baseName = name.substring(0, endIndex);
String suffix = endIndex < name.length() ? name.substring(endIndex) : "";
Var typeDeclaration = t.getScope().getVar(baseName);
// Make sure we can find a variable declaration (and it's in this file)
if (typeDeclaration != null && typeDeclaration.getNode() != null
&& Objects.equals(typeDeclaration.getNode().getInputId(), typeNode.getInputId())) {
String importedModuleName = getModuleImportName(t, typeDeclaration.getNode());
// If the name is an import alias, rewrite it to be a reference to the
// module name directly
if (importedModuleName != null) {
typeNode.setString(importedModuleName + suffix);
typeNode.setOriginalName(name);
wasRewritten = true;
break;
} else if (this.allowFullRewrite) {
// Names referenced in export statements can only be rewritten in
// commonjs modules.
String exportedName = getExportedName(t, typeNode, typeDeclaration);
if (exportedName != null && !exportedName.equals(name)) {
typeNode.setString(exportedName + suffix);
typeNode.setOriginalName(name);
wasRewritten = true;
break;
}
}
}
}
// If the name was neither an import alias or referenced in an export,
// We still may need to rename it if it's global
if (!wasRewritten && this.allowFullRewrite) {
endIndex = name.indexOf('.');
if (endIndex == -1) {
endIndex = name.length();
}
String baseName = name.substring(0, endIndex);
Var typeDeclaration = t.getScope().getVar(baseName);
if (typeDeclaration != null && typeDeclaration.isGlobal()) {
String moduleName = getModuleName(t.getInput());
String newName = baseName + "$$" + moduleName;
if (endIndex < name.length()) {
newName += name.substring(endIndex);
}
typeNode.setString(newName);
typeNode.setOriginalName(name);
}
}
}
}
for (Node child = typeNode.getFirstChild(); child != null;
child = child.getNext()) {
fixTypeNode(t, child);
}
}
private List splitMultipleDeclarations(Node var) {
checkState(NodeUtil.isNameDeclaration(var));
List vars = new ArrayList<>();
JSDocInfo info = var.getJSDocInfo();
while (var.getSecondChild() != null) {
Node newVar = new Node(var.getToken(), var.removeFirstChild());
if (info != null) {
newVar.setJSDocInfo(info.clone());
}
newVar.useSourceInfoFrom(var);
var.getParent().addChildBefore(newVar, var);
vars.add(newVar);
}
vars.add(var);
return vars;
}
}
}