com.google.javascript.jscomp.FindModuleDependencies Maven / Gradle / Ivy
/*
* Copyright 2017 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 com.google.javascript.jscomp.CompilerInput.ModuleType;
import com.google.javascript.jscomp.Es6RewriteModules.FindGoogProvideOrGoogModule;
import com.google.javascript.jscomp.deps.ModuleLoader;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
/**
* Find and update any direct dependencies of an input. Used to walk the dependency graph and
* support a strict depth-first dependency ordering. Marks an input as providing its module name.
*
* Discovers dependencies from:
*
* - goog.require calls
*
- ES6 import statements
*
- CommonJS require statements
*
*
* The order of dependency references is preserved so that a deterministic depth-first ordering
* can be achieved.
*
* @author [email protected] (Chad Killingsworth)
*/
public class FindModuleDependencies extends NodeTraversal.AbstractPostOrderCallback {
private final AbstractCompiler compiler;
private final boolean supportsEs6Modules;
private final boolean supportsCommonJsModules;
private ModuleType moduleType = ModuleType.NONE;
FindModuleDependencies(
AbstractCompiler compiler, boolean supportsEs6Modules, boolean supportsCommonJsModules) {
this.compiler = compiler;
this.supportsEs6Modules = supportsEs6Modules;
this.supportsCommonJsModules = supportsCommonJsModules;
}
public void process(Node root) {
checkArgument(root.isScript());
if (Es6RewriteModules.isEs6ModuleRoot(root)) {
moduleType = ModuleType.ES6;
}
CompilerInput input = compiler.getInput(root.getInputId());
// The "goog" namespace isn't always specifically required.
// The deps parser will pick up any access to a `goog.foo()` call
// and add "goog" as a dependency. If "goog" is a dependency of the
// file we add it here to the ordered requires so that it's always
// first.
if (input.getRequires().contains("goog")) {
input.addOrderedRequire("goog");
}
NodeTraversal.traverseEs6(compiler, root, this);
if (moduleType == ModuleType.ES6) {
convertToEs6Module(root, true);
}
input.addProvide(input.getPath().toModuleName());
input.setJsModuleType(moduleType);
input.setHasFullParseDependencyInfo(true);
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
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"))) {
moduleType = ModuleType.GOOG;
return;
}
}
}
if (supportsEs6Modules && n.isExport()) {
moduleType = ModuleType.ES6;
if (n.getBooleanProp(Node.EXPORT_DEFAULT)) {
// export default
} else if (n.hasTwoChildren()) {
// export * from 'moduleIdentifier';
// export {x, y as z} from 'moduleIdentifier';
addEs6ModuleImportToGraph(t, n);
}
} else if (supportsEs6Modules && n.isImport()) {
moduleType = ModuleType.ES6;
addEs6ModuleImportToGraph(t, n);
} else if (supportsCommonJsModules) {
if (moduleType != ModuleType.GOOG && ProcessCommonJSModules.isCommonJsExport(t, n)) {
moduleType = ModuleType.COMMONJS;
} else if (ProcessCommonJSModules.isCommonJsImport(n)) {
String path = ProcessCommonJSModules.getCommonJsImportPath(n);
ModuleLoader.ModulePath modulePath =
t.getInput()
.getPath()
.resolveJsModule(path, n.getSourceFileName(), n.getLineno(), n.getCharno());
if (modulePath != null) {
t.getInput().addOrderedRequire(modulePath.toModuleName());
}
}
// TODO(ChadKillingsworth) add require.ensure support
}
if (parent != null
&& (parent.isExprResult() || !t.inGlobalHoistScope())
&& n.isCall()
&& n.getFirstChild().matchesQualifiedName("goog.require")
&& n.getSecondChild() != null
&& n.getSecondChild().isString()) {
String namespace = n.getSecondChild().getString();
if (namespace.startsWith("goog.")) {
t.getInput().addOrderedRequire("goog");
}
t.getInput().addOrderedRequire(namespace);
}
}
/**
* Convert a script into a module by marking it's root node as a module body. This allows a script
* which is imported as a module to be scoped as a module even without "import" or "export"
* statements. Fails if the file contains a goog.provide or goog.module.
*
* @return True, if the file is now an ES6 module. False, if the file must remain a script.
*/
public boolean convertToEs6Module(Node root) {
return this.convertToEs6Module(root, false);
}
/**
* Adds an es6 module from an import node (import or export statement) to the graph.
*/
private void addEs6ModuleImportToGraph(NodeTraversal t, Node n) {
String moduleName = getEs6ModuleNameFromImportNode(t, n);
if (moduleName.startsWith("goog.")) {
t.getInput().addOrderedRequire("goog");
}
t.getInput().addOrderedRequire(moduleName);
}
/**
* Get the module name from an import node (import or export statement).
*/
private String getEs6ModuleNameFromImportNode(NodeTraversal t, Node n) {
String importName = n.getLastChild().getString();
boolean isNamespaceImport = importName.startsWith("goog:");
if (isNamespaceImport) {
// Allow importing Closure namespace objects (e.g. from goog.provide or goog.module) as
// import ... from 'goog:my.ns.Object'.
// These are rewritten to plain namespace object accesses.
return importName.substring("goog:".length());
} else {
ModuleLoader.ModulePath modulePath =
t.getInput()
.getPath()
.resolveJsModule(importName, n.getSourceFileName(), n.getLineno(), n.getCharno());
if (modulePath == null) {
// The module loader issues an error
// Fall back to assuming the module is a file path
modulePath = t.getInput().getPath().resolveModuleAsPath(importName);
}
return modulePath.toModuleName();
}
}
private boolean convertToEs6Module(Node root, boolean skipGoogProvideModuleCheck) {
if (Es6RewriteModules.isEs6ModuleRoot(root)) {
return true;
}
if (!skipGoogProvideModuleCheck) {
FindGoogProvideOrGoogModule finder = new FindGoogProvideOrGoogModule();
NodeTraversal.traverseEs6(compiler, root, finder);
if (finder.isFound()) {
return false;
}
}
Node moduleNode = new Node(Token.MODULE_BODY).srcref(root);
moduleNode.addChildrenToBack(root.removeChildren());
root.addChildToBack(moduleNode);
return true;
}
}