com.google.debugging.sourcemap.SourceMapObjectParserJs.java Source code

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Here is the source code for com.google.debugging.sourcemap.SourceMapObjectParserJs.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.debugging.sourcemap;

import com.google.common.collect.ImmutableList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
import jsinterop.annotations.JsMethod;
import jsinterop.annotations.JsPackage;
import jsinterop.annotations.JsType;

/**
 * ClientSide implementation of the source map parser using jsinterop.
 *
 * Note: This is invoked through super sourcing of SourceMapObjectParser.
 */
public class SourceMapObjectParserJs {

    // TODO(dankurka): Use elemental2 here once available
    @JsMethod(name = "parse", namespace = "JSON")
    private static native Object parseJson(String json);

    // TODO(dankurka): Use elemental2 here once available
    @JsMethod(name = "keys", namespace = "Object")
    private static native String[] keys(Object o);

    // TODO(dankurka): Switch to our general util once available
    // JsMethod to prevent mangling
    @JsMethod
    public static native Object get(Object o, String key) /*-{
                                                          return o[key];
                                                          }-*/;

    @JsType(isNative = true, name = "Object", namespace = JsPackage.GLOBAL)
    private static class JsonMap {
        int version;
        String file;
        String mappings;
        String sourceRoot;
        Section[] sections;
        String[] sources;
        String[] names;
    }

    @JsType(isNative = true, name = "Object", namespace = JsPackage.GLOBAL)
    private static class Section {
        Offset offset;
        String url;
        String map;
    }

    @JsType(isNative = true, name = "Object", namespace = JsPackage.GLOBAL)
    private static class Offset {
        int line;
        int column;
    }

    public static SourceMapObject parse(String contents) throws SourceMapParseException {

        SourceMapObject.Builder builder = SourceMapObject.builder();

        Object jsonInstance = null;

        try {
            jsonInstance = parseJson(contents);
        } catch (Exception ex) {
            throw new SourceMapParseException("JSON parse exception: " + ex);
        }

        JsonMap sourceMap = (JsonMap) jsonInstance;

        builder.setVersion(sourceMap.version);
        builder.setFile(sourceMap.file);
        // Line count is no longer part of the source map spec. -1 is the magic "not provided" value
        builder.setLineCount(-1);
        builder.setMappings(sourceMap.mappings);
        builder.setSourceRoot(sourceMap.sourceRoot);

        if (sourceMap.sections != null) {
            ImmutableList.Builder<SourceMapSection> listBuilder = ImmutableList.builder();
            for (Section section : sourceMap.sections) {
                listBuilder.add(buildSection(section));
            }
            builder.setSections(listBuilder.build());
        } else {
            builder.setSections(null);
        }

        builder.setSources(sourceMap.sources);
        builder.setNames(sourceMap.names);

        Map<String, Object> extensions = new LinkedHashMap<>();
        String[] keys = keys(sourceMap);

        for (String key : keys) {
            if (key.startsWith("x_")) {
                extensions.put(key, get(sourceMap, key));
            }
        }

        builder.setExtensions(Collections.unmodifiableMap(extensions));
        return builder.build();
    }

    private static SourceMapSection buildSection(Section section) throws SourceMapParseException {
        int line = section.offset.line;
        int column = section.offset.column;

        if (section.map != null && section.url != null) {
            throw new SourceMapParseException("Invalid map format: section may not have both 'map' and 'url'");
        } else if (section.url != null) {
            return SourceMapSection.forURL(section.url, line, column);
        } else if (section.map != null) {
            return SourceMapSection.forMap(String.valueOf(section.map), line, column);
        }

        throw new SourceMapParseException("Invalid map format: section must have either 'map' or 'url'");
    }
}