com.google.javascript.jscomp.PolymerPassFindExterns.java Source code

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Here is the source code for com.google.javascript.jscomp.PolymerPassFindExterns.java

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/*
 * 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.collect.ImmutableList;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.rhino.Node;

/**
 * Finds the externs for the PolymerElement base class and all of its properties in the externs.
 */
final class PolymerPassFindExterns extends AbstractPostOrderCallback {

    private static final String POLYMER_ELEMENT_NAME = "PolymerElement";

    private Node polymerElementExterns;
    private final ImmutableList.Builder<Node> polymerElementProps;

    PolymerPassFindExterns() {
        polymerElementProps = ImmutableList.builder();
    }

    @Override
    public void visit(NodeTraversal t, Node n, Node parent) {
        if (isPolymerElementExterns(n)) {
            polymerElementExterns = n;
        } else if (isPolymerElementPropExpr(n)) {
            polymerElementProps.add(n);
        }
    }

    /**
     * @return All properties of the {@code PolymerElement} class in externs.
     */
    ImmutableList<Node> getPolymerElementProps() {
        return polymerElementProps.build();
    }

    /**
     * @return The root {@link Node} {@code PolymerElement} class in externs.
     */
    Node getPolymerElementExterns() {
        return polymerElementExterns;
    }

    /**
     * @return Whether the node is the declaration of PolymerElement.
     */
    private static boolean isPolymerElementExterns(Node value) {
        // Explicitly allow var, let or const.
        return NodeUtil.isNameDeclaration(value)
                && value.getFirstChild().matchesQualifiedName(POLYMER_ELEMENT_NAME);
    }

    /**
     * @return Whether the node is an expression result of an assignment to a property of
     * PolymerElement.
     */
    private static boolean isPolymerElementPropExpr(Node value) {
        return value != null && value.isExprResult() && value.getFirstFirstChild() != null
                && value.getFirstFirstChild().isGetProp() && value.getFirstFirstChild().isQualifiedName()
                && NodeUtil.getRootOfQualifiedName(value.getFirstFirstChild())
                        .matchesQualifiedName(POLYMER_ELEMENT_NAME);
    }
}