com.google.javascript.jscomp.PolymerClassRewriter Maven / Gradle / Ivy
/*
* Copyright 2016 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 com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.javascript.jscomp.PolymerBehaviorExtractor.BehaviorDefinition;
import com.google.javascript.jscomp.PolymerPass.MemberDefinition;
import com.google.javascript.jscomp.parsing.parser.FeatureSet;
import com.google.javascript.rhino.IR;
import com.google.javascript.rhino.JSDocInfo.Visibility;
import com.google.javascript.rhino.JSDocInfoBuilder;
import com.google.javascript.rhino.JSTypeExpression;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Rewrites a given call to Polymer({}) to a set of declarations and assignments which can be
* understood by the compiler.
*/
final class PolymerClassRewriter {
private final AbstractCompiler compiler;
private Node polymerElementExterns;
PolymerClassRewriter(AbstractCompiler compiler, Node polymerElementExterns) {
this.compiler = compiler;
this.polymerElementExterns = polymerElementExterns;
}
/**
* Rewrites a given call to Polymer({}) to a set of declarations and assignments which can be
* understood by the compiler.
*
* @param exprRoot The root expression of the call to Polymer({}).
* @param cls The extracted {@link PolymerClassDefinition} for the Polymer element created by this
* call.
*/
void rewritePolymerClass(
Node exprRoot, final PolymerClassDefinition cls, boolean isInGlobalScope) {
Node call = exprRoot.getFirstChild();
if (call.isAssign()) {
call = call.getSecondChild();
} else if (call.isName()) {
call = call.getFirstChild();
}
Node objLit = cls.descriptor;
if (hasShorthandAssignment(objLit)) {
compiler.report(JSError.make(objLit, PolymerPassErrors.POLYMER_SHORTHAND_NOT_SUPPORTED));
return;
}
// Add {@code @lends} to the object literal.
JSDocInfoBuilder objLitDoc = new JSDocInfoBuilder(true);
objLitDoc.recordLends(cls.target.getQualifiedName() + ".prototype");
objLit.setJSDocInfo(objLitDoc.build());
addTypesToFunctions(objLit, cls.target.getQualifiedName());
PolymerPassStaticUtils.switchDollarSignPropsToBrackets(objLit, compiler);
PolymerPassStaticUtils.quoteListenerAndHostAttributeKeys(objLit);
for (MemberDefinition prop : cls.props) {
if (prop.value.isObjectLit()) {
PolymerPassStaticUtils.switchDollarSignPropsToBrackets(prop.value, compiler);
}
}
// For simplicity add everything into a block, before adding it to the AST.
Node block = IR.block();
JSDocInfoBuilder constructorDoc = this.getConstructorDoc(cls);
// Remove the original constructor JS docs from the objlit.
Node ctorKey = cls.constructor.value.getParent();
if (ctorKey != null) {
ctorKey.removeProp(Node.JSDOC_INFO_PROP);
}
if (cls.target.isGetProp()) {
// foo.bar = Polymer({...});
Node assign = IR.assign(
cls.target.cloneTree(),
cls.constructor.value.cloneTree());
assign.setJSDocInfo(constructorDoc.build());
Node exprResult = IR.exprResult(assign);
exprResult.useSourceInfoIfMissingFromForTree(cls.target);
block.addChildToBack(exprResult);
} else {
// var foo = Polymer({...}); OR Polymer({...});
Node var = IR.var(cls.target.cloneTree(), cls.constructor.value.cloneTree());
var.useSourceInfoIfMissingFromForTree(exprRoot);
var.setJSDocInfo(constructorDoc.build());
block.addChildToBack(var);
}
appendPropertiesToBlock(cls, block, cls.target.getQualifiedName() + ".prototype.");
appendBehaviorMembersToBlock(cls, block);
ImmutableList readOnlyProps = parseReadOnlyProperties(cls, block);
addInterfaceExterns(cls, readOnlyProps);
removePropertyDocs(objLit);
Node statements = block.removeChildren();
Node parent = exprRoot.getParent();
// If the call to Polymer() is not in the global scope and the assignment target is not
// namespaced (which likely means it's exported to the global scope), put the type declaration
// into the global scope at the start of the current script.
//
// This avoids unknown type warnings which are a result of the compiler's poor understanding of
// types declared inside IIFEs or any non-global scope. We should revisit this decision after
// moving to the new type inference system which should be able to infer these types better.
if (!isInGlobalScope && !cls.target.isGetProp()) {
Node scriptNode = NodeUtil.getEnclosingScript(parent);
scriptNode.addChildrenToFront(statements);
} else {
Node beforeRoot = exprRoot.getPrevious();
if (beforeRoot == null) {
parent.addChildrenToFront(statements);
} else {
parent.addChildrenAfter(statements, beforeRoot);
}
}
// Since behavior files might contain more language features than the class file, we need to
// update the feature sets.
FeatureSet newFeatures = cls.features;
if (newFeatures != null) {
Node scriptNode = NodeUtil.getEnclosingScript(parent);
FeatureSet oldFeatures = (FeatureSet) scriptNode.getProp(Node.FEATURE_SET);
scriptNode.putProp(Node.FEATURE_SET, oldFeatures.union(newFeatures));
}
if (NodeUtil.isNameDeclaration(exprRoot)) {
Node assignExpr = varToAssign(exprRoot);
parent.replaceChild(exprRoot, assignExpr);
}
compiler.reportCodeChange();
}
/**
* Adds an @this annotation to all functions in the objLit.
*/
private void addTypesToFunctions(Node objLit, String thisType) {
Preconditions.checkState(objLit.isObjectLit());
for (Node keyNode : objLit.children()) {
Node value = keyNode.getLastChild();
if (value != null && value.isFunction()) {
JSDocInfoBuilder fnDoc = JSDocInfoBuilder.maybeCopyFrom(keyNode.getJSDocInfo());
fnDoc.recordThisType(new JSTypeExpression(
new Node(Token.BANG, IR.string(thisType)), PolymerPass.VIRTUAL_FILE));
keyNode.setJSDocInfo(fnDoc.build());
}
}
// Add @this and @return to default property values.
for (MemberDefinition property : PolymerPassStaticUtils.extractProperties(objLit, compiler)) {
if (!property.value.isObjectLit()) {
continue;
}
if (hasShorthandAssignment(property.value)){
compiler.report(
JSError.make(property.value, PolymerPassErrors.POLYMER_SHORTHAND_NOT_SUPPORTED));
return;
}
Node defaultValue = NodeUtil.getFirstPropMatchingKey(property.value, "value");
if (defaultValue == null || !defaultValue.isFunction()) {
continue;
}
Node defaultValueKey = defaultValue.getParent();
JSDocInfoBuilder fnDoc = JSDocInfoBuilder.maybeCopyFrom(defaultValueKey.getJSDocInfo());
fnDoc.recordThisType(new JSTypeExpression(
new Node(Token.BANG, IR.string(thisType)), PolymerPass.VIRTUAL_FILE));
fnDoc.recordReturnType(PolymerPassStaticUtils.getTypeFromProperty(property, compiler));
defaultValueKey.setJSDocInfo(fnDoc.build());
}
}
/**
* Generates the _set* setters for readonly properties and appends them to the given block.
* @return A List of all readonly properties.
*/
private ImmutableList parseReadOnlyProperties(
final PolymerClassDefinition cls, Node block) {
String qualifiedPath = cls.target.getQualifiedName() + ".prototype.";
ImmutableList.Builder readOnlyProps = ImmutableList.builder();
for (MemberDefinition prop : cls.props) {
// Generate the setter for readOnly properties.
if (prop.value.isObjectLit()) {
Node readOnlyValue = NodeUtil.getFirstPropMatchingKey(prop.value, "readOnly");
if (readOnlyValue != null && readOnlyValue.isTrue()) {
Node setter = makeReadOnlySetter(prop.name.getString(), qualifiedPath);
setter.useSourceInfoIfMissingFromForTree(prop.name);
block.addChildToBack(setter);
readOnlyProps.add(prop);
}
}
}
return readOnlyProps.build();
}
/**
* @return The proper constructor doc for the Polymer call.
*/
private JSDocInfoBuilder getConstructorDoc(final PolymerClassDefinition cls) {
JSDocInfoBuilder constructorDoc = JSDocInfoBuilder.maybeCopyFrom(cls.constructor.info);
constructorDoc.recordConstructor();
JSTypeExpression baseType = new JSTypeExpression(
new Node(Token.BANG, IR.string(PolymerPassStaticUtils.getPolymerElementType(cls))),
PolymerPass.VIRTUAL_FILE);
constructorDoc.recordBaseType(baseType);
String interfaceName = getInterfaceName(cls);
JSTypeExpression interfaceType = new JSTypeExpression(
new Node(Token.BANG, IR.string(interfaceName)), PolymerPass.VIRTUAL_FILE);
constructorDoc.recordImplementedInterface(interfaceType);
return constructorDoc;
}
/**
* Appends all properties in the ClassDefinition to the prototype of the custom element.
*/
private void appendPropertiesToBlock(
final PolymerClassDefinition cls, Node block, String basePath) {
for (MemberDefinition prop : cls.props) {
Node propertyNode = IR.exprResult(
NodeUtil.newQName(compiler, basePath + prop.name.getString()));
propertyNode.useSourceInfoIfMissingFromForTree(prop.name);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(prop.info);
JSTypeExpression propType = PolymerPassStaticUtils.getTypeFromProperty(prop, compiler);
if (propType == null) {
return;
}
info.recordType(propType);
propertyNode.getFirstChild().setJSDocInfo(info.build());
block.addChildToBack(propertyNode);
}
}
/**
* Remove all JSDocs from properties of a class definition
*/
private void removePropertyDocs(final Node objLit) {
for (MemberDefinition prop : PolymerPassStaticUtils.extractProperties(objLit, compiler)) {
prop.name.removeProp(Node.JSDOC_INFO_PROP);
}
}
/**
* Appends all required behavior functions and non-property members to the given block.
*/
private void appendBehaviorMembersToBlock(final PolymerClassDefinition cls, Node block) {
String qualifiedPath = cls.target.getQualifiedName() + ".prototype.";
Map nameToExprResult = new HashMap<>();
for (BehaviorDefinition behavior : cls.behaviors) {
for (MemberDefinition behaviorFunction : behavior.functionsToCopy) {
String fnName = behaviorFunction.name.getString();
// Don't copy functions already defined by the element itself.
if (NodeUtil.getFirstPropMatchingKey(cls.descriptor, fnName) != null) {
continue;
}
// Avoid copying over the same function twice. The last definition always wins.
if (nameToExprResult.containsKey(fnName)) {
block.removeChild(nameToExprResult.get(fnName));
}
Node fnValue = behaviorFunction.value.cloneTree();
Node exprResult = IR.exprResult(
IR.assign(NodeUtil.newQName(compiler, qualifiedPath + fnName), fnValue));
exprResult.useSourceInfoIfMissingFromForTree(behaviorFunction.name);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(behaviorFunction.info);
// Uses of private members that come from behaviors are not recognized correctly,
// so just suppress that warning.
info.addSuppression("unusedPrivateMembers");
// If the function in the behavior is @protected, switch it to @public so that
// we don't get a visibility warning. This is a bit of a hack but easier than
// making the type system understand that methods are "inherited" from behaviors.
if (behaviorFunction.info != null
&& behaviorFunction.info.getVisibility() == Visibility.PROTECTED) {
info.overwriteVisibility(Visibility.PUBLIC);
}
// Behaviors whose declarations are not in the global scope may contain references to
// symbols which do not exist in the element's scope. Only copy a function stub.
if (!behavior.isGlobalDeclaration) {
NodeUtil.getFunctionBody(fnValue).removeChildren();
}
exprResult.getFirstChild().setJSDocInfo(info.build());
block.addChildToBack(exprResult);
nameToExprResult.put(fnName, exprResult);
}
// Copy other members.
for (MemberDefinition behaviorProp : behavior.nonPropertyMembersToCopy) {
String propName = behaviorProp.name.getString();
if (nameToExprResult.containsKey(propName)) {
block.removeChild(nameToExprResult.get(propName));
}
Node exprResult = IR.exprResult(NodeUtil.newQName(compiler, qualifiedPath + propName));
exprResult.useSourceInfoFromForTree(behaviorProp.name);
JSDocInfoBuilder info = JSDocInfoBuilder.maybeCopyFrom(behaviorProp.info);
if (behaviorProp.name.isGetterDef()) {
info = new JSDocInfoBuilder(true);
if (behaviorProp.info != null && behaviorProp.info.getReturnType() != null) {
info.recordType(behaviorProp.info.getReturnType());
}
}
exprResult.getFirstChild().setJSDocInfo(info.build());
block.addChildToBack(exprResult);
nameToExprResult.put(propName, exprResult);
}
}
}
/**
* Adds the generated setter for a readonly property.
* @see https://www.polymer-project.org/0.8/docs/devguide/properties.html#read-only
*/
private Node makeReadOnlySetter(String propName, String qualifiedPath) {
String setterName = "_set" + propName.substring(0, 1).toUpperCase() + propName.substring(1);
Node fnNode = IR.function(IR.name(""), IR.paramList(IR.name(propName)), IR.block());
Node exprResNode = IR.exprResult(
IR.assign(NodeUtil.newQName(compiler, qualifiedPath + setterName), fnNode));
JSDocInfoBuilder info = new JSDocInfoBuilder(true);
// This is overriding a generated function which was added to the interface in
// {@code addInterfaceExterns}.
info.recordOverride();
exprResNode.getFirstChild().setJSDocInfo(info.build());
return exprResNode;
}
/**
* Adds an interface for the given ClassDefinition to externs. This allows generated setter
* functions for read-only properties to avoid renaming altogether.
* @see https://www.polymer-project.org/0.8/docs/devguide/properties.html#read-only
*/
private void addInterfaceExterns(
final PolymerClassDefinition cls, List readOnlyProps) {
Node block = IR.block();
String interfaceName = getInterfaceName(cls);
Node fnNode = IR.function(IR.name(""), IR.paramList(), IR.block());
Node varNode = IR.var(NodeUtil.newQName(compiler, interfaceName), fnNode);
JSDocInfoBuilder info = new JSDocInfoBuilder(true);
info.recordInterface();
varNode.setJSDocInfo(info.build());
block.addChildToBack(varNode);
appendPropertiesToBlock(cls, block, interfaceName + ".prototype.");
for (MemberDefinition prop : readOnlyProps) {
// Add all _set* functions to avoid renaming.
String propName = prop.name.getString();
String setterName = "_set" + propName.substring(0, 1).toUpperCase() + propName.substring(1);
Node setterExprNode = IR.exprResult(
NodeUtil.newQName(compiler, interfaceName + ".prototype." + setterName));
JSDocInfoBuilder setterInfo = new JSDocInfoBuilder(true);
JSTypeExpression propType = PolymerPassStaticUtils.getTypeFromProperty(prop, compiler);
setterInfo.recordParameter(propName, propType);
setterExprNode.getFirstChild().setJSDocInfo(setterInfo.build());
block.addChildToBack(setterExprNode);
}
block.useSourceInfoIfMissingFromForTree(polymerElementExterns);
Node parent = polymerElementExterns.getParent();
Node stmts = block.removeChildren();
parent.addChildrenToBack(stmts);
compiler.reportCodeChange();
}
private static boolean hasShorthandAssignment(Node objLit) {
Preconditions.checkState(objLit.isObjectLit());
for (Node property : objLit.children()){
if (property.isStringKey() && !property.hasChildren()){
return true;
}
}
return false;
}
/**
* @return The name of the generated extern interface which the element implements.
*/
private static String getInterfaceName(final PolymerClassDefinition cls) {
return "Polymer" + cls.target.getQualifiedName().replaceAll("\\.", "_") + "Interface";
}
/**
* @return An assign replacing the equivalent var or let declaration.
*/
private static Node varToAssign(Node var) {
Node assign = IR.assign(
var.getFirstChild().cloneNode(),
var.getFirstChild().removeFirstChild());
return IR.exprResult(assign).useSourceInfoIfMissingFromForTree(var);
}
}
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