com.google.api.codegen.MixedPathTestDataLocator.java Source code

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Here is the source code for com.google.api.codegen.MixedPathTestDataLocator.java

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/* Copyright 2018 Google LLC
 *
 * 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
 *
 *      https://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.api.codegen;

import com.google.api.tools.framework.model.testing.ClassPathTestDataLocator;
import com.google.common.collect.ImmutableList;
import com.google.common.io.CharStreams;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;
import javax.annotation.Nullable;

/**
 * A test data locator which first tries to find the specified resource on a file system, and if the
 * file was not found this class fallbacks to the default ({@link ClassPathTestDataLocator})
 * implementation.
 *
 * <p>This behavior is useful for cases when some parts of test infrastructure expect an actual file
 * on a disk (instead of classpath resource) and the resource is packaged inside a jar file (thus
 * cannot be handled as a regular file). Specifically when a test is executed by gradle or IDE the
 * compiled code and its resources are not packaged in a jar file, thus a resource can be read as a
 * regular file. Unfortunately it does not work that well in bazel, which normally packages compiled
 * classes and resources in a single jar file.
 */
public class MixedPathTestDataLocator extends ClassPathTestDataLocator {

    private final List<String> pathPrefixes;

    public MixedPathTestDataLocator(Class<?> classContext, String... pathPrefixes) {
        super(classContext);
        this.pathPrefixes = ImmutableList.copyOf(pathPrefixes);
    }

    @Nullable
    @Override
    public URL resolveTestData(String name) {
        for (String pathPrefix : pathPrefixes) {
            try {
                Path filePath = Paths.get(pathPrefix, name);
                if (Files.isReadable(filePath)) {
                    return filePath.toUri().toURL();
                }
            } catch (MalformedURLException e) {
                // Ignore, try another path or fallback to parent's implementation.
            }
        }
        return super.resolveTestData(name);
    }

    @Override
    public String fetchTestData(URL url) {
        if ("file".equals(url.getProtocol())) {
            try (Reader reader = new InputStreamReader(url.openStream())) {
                return CharStreams.toString(reader);
            } catch (IOException e) {
                // Ignore, fallback to parent's implementation.
            }
        }

        return super.fetchTestData(url);
    }
}