com.google.javascript.refactoring.testing.RefasterJsTestCase Maven / Gradle / Ivy

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Closure Compiler is a JavaScript optimizing compiler. It parses your JavaScript, analyzes it, removes dead code and rewrites and minimizes what's left. It also checks syntax, variable references, and types, and warns about common JavaScript pitfalls. It is used in many of Google's JavaScript apps, including Gmail, Google Web Search, Google Maps, and Google Docs.

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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.refactoring.testing;

import static com.google.common.collect.ImmutableList.toImmutableList;
import static com.google.common.truth.Truth.assertThat;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.auto.value.AutoValue;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.io.Files;
import com.google.common.truth.Correspondence;
import com.google.javascript.jscomp.CommandLineRunner;
import com.google.javascript.jscomp.CompilerOptions;
import com.google.javascript.refactoring.ApplySuggestedFixes;
import com.google.javascript.refactoring.RefactoringDriver;
import com.google.javascript.refactoring.RefasterJsScanner;
import com.google.javascript.refactoring.SuggestedFix;
import java.io.File;
import java.io.IOException;
import java.util.List;

/** RefasterJsTestCase */
@AutoValue
public abstract class RefasterJsTestCase {

  public static Builder builder() {
    return new AutoValue_RefasterJsTestCase.Builder();
  }

  /** Path of the resource containing the RefasterJs template to apply. */
  public abstract String getTemplatePath();

  /** Path of the resource containing the input JS file. */
  public abstract String getInputPath();

  /** Paths of the resources containing the expected output JS files. */
  public abstract ImmutableSet getExpectedOutputPaths();

  /** Paths of the resources containing other JS files to include. */
  public abstract ImmutableSet getAdditionalSourcePaths();

  /** Builder */
  @AutoValue.Builder
  public abstract static class Builder {

    public abstract Builder setTemplatePath(String x);

    public abstract Builder setInputPath(String x);

    public final Builder addExpectedOutputPath(String x) {
      this.expectedOutputPathsBuilder().add(x);
      return this;
    }

    public final Builder addAdditionalSourcePath(String x) {
      this.additionalSourcePathsBuilder().add(x);
      return this;
    }

    public final void test() {
      try {
        this.build().test();
      } catch (IOException e) {
        throw new AssertionError(e);
      }
    }

    abstract ImmutableSet.Builder expectedOutputPathsBuilder();

    abstract ImmutableSet.Builder additionalSourcePathsBuilder();

    abstract RefasterJsTestCase build();
  }

  private void test() throws IOException {
    // Given
    RefasterJsScanner scanner = new RefasterJsScanner();
    scanner.loadRefasterJsTemplate(this.getTemplatePath());

    ImmutableList expectedOutputs =
        this.getExpectedOutputPaths().stream()
            .map(RefasterJsTestCase::slurpFile)
            .collect(toImmutableList());

    RefactoringDriver.Builder driverBuilder =
        new RefactoringDriver.Builder()
            .addExterns(CommandLineRunner.getBuiltinExterns(CompilerOptions.Environment.BROWSER));
    for (String additionalSourcePath : this.getAdditionalSourcePaths()) {
      driverBuilder.addInputsFromFile(additionalSourcePath);
    }
    RefactoringDriver driver = driverBuilder.addInputsFromFile(this.getInputPath()).build();

    // When
    List fixes = driver.drive(scanner);
    ImmutableList newCode =
        ApplySuggestedFixes.applyAllSuggestedFixChoicesToCode(
                fixes, ImmutableMap.of(this.getInputPath(), slurpFile(this.getInputPath())))
            .stream()
            .map(m -> m.get(this.getInputPath()))
            .collect(toImmutableList());

    // Then
    assertThat(driver.getCompiler().getErrors()).isEmpty();
    assertThat(driver.getCompiler().getWarnings()).isEmpty();
    assertThat(newCode)
        .comparingElementsUsing(IGNORING_WHITESPACE_CORRESPONDENCE)
        .containsExactlyElementsIn(expectedOutputs);
  }

  private static String slurpFile(String originalFile) {
    try {
      return Files.asCharSource(new File(originalFile), UTF_8).read();
    } catch (IOException e) {
      throw new AssertionError(e);
    }
  }

  private static final Correspondence IGNORING_WHITESPACE_CORRESPONDENCE =
      Correspondence.transforming(
          RefasterJsTestCase::replaceTrailingWhitespace,
          RefasterJsTestCase::replaceTrailingWhitespace,
          "equals (except for whitespace)");

  private static String replaceTrailingWhitespace(String contents) {
    return contents.replaceAll("[ \t]*\n", "\n");
  }

  RefasterJsTestCase() {
    // Only subclassed by AutoValue.
  }
}