GenericDiffReporter.java

package org.approvaltests.reporters;

import java.io.File;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.Arrays;
import java.util.List;

import com.spun.util.SystemUtils;
import com.spun.util.ThreadUtils;
import com.spun.util.io.FileUtils;

public class GenericDiffReporter implements EnvironmentAwareReporter
{
  public static final String STANDARD_ARGUMENTS    = "%s %s";
  public static boolean      REPORT_MISSING_FILES  = false;
  protected String           diffProgram;
  protected String           arguments;
  protected String           diffProgramNotFoundMessage;
  private List<String>       validExtensions;
  public static List<String> TEXT_FILE_EXTENSIONS  = Arrays.asList(".txt", ".csv", ".htm", ".html", ".xml", ".eml",
      ".java", ".css", ".js", ".json");
  public static List<String> IMAGE_FILE_EXTENSIONS = Arrays.asList(".png", ".gif", ".jpg", ".jpeg", ".bmp", ".tif",
      ".tiff");
  public GenericDiffReporter(String diffProgram, String diffProgramNotFoundMessage)
  {
    this(diffProgram, STANDARD_ARGUMENTS, diffProgramNotFoundMessage);
  }
  private GenericDiffReporter(String diffProgram, String argumentsFormat, String diffProgramNotFoundMessage)
  {
    this(diffProgram, argumentsFormat, diffProgramNotFoundMessage, TEXT_FILE_EXTENSIONS);
  }
  public GenericDiffReporter(String diffProgram, String argumentsFormat, String diffProgramNotFoundMessage,
      List<String> validFileExtensions)
  {
    this.diffProgram = diffProgram;
    this.arguments = argumentsFormat;
    this.diffProgramNotFoundMessage = diffProgramNotFoundMessage;
    validExtensions = validFileExtensions;
  }
  public GenericDiffReporter(DiffInfo info)
  {
    this(info.diffProgram, info.parameters,
        MessageFormat.format("Unable to find program at {0}", info.diffProgram), info.fileExtensions);
  }
  @Override
  public void report(String received, String approved) throws Exception
  {
    if (!isWorkingInThisEnvironment(received)) { throw new RuntimeException(diffProgramNotFoundMessage); }
    FileUtils.createIfNeeded(approved);
    launch(received, approved);
  }
  private void launch(String received, String approved) throws IOException
  {
    ProcessBuilder builder = new ProcessBuilder(getCommandLine(received, approved));
    preventProcessFromClosing(builder);
    Process process = builder.start();
    ThreadUtils.sleep(800); //Give program time to start
  }
  private void preventProcessFromClosing(ProcessBuilder builder)
  {
    if (!SystemUtils.isWindowsEnviroment())
    {
      File output = new File("/dev/null");
      builder.redirectError(output).redirectOutput(output);
    }
  }
  public String[] getCommandLine(String received, String approved)
  {
    String[] p = arguments.split(" ");
    String r = String.format(p[0], received);
    String a = String.format(p[1], approved);
    String[] commands = new String[]{diffProgram, r, a};
    System.out.println(Arrays.toString(commands));
    return commands;
  }
  @Override
  public boolean isWorkingInThisEnvironment(String forFile)
  {
    return checkFileExists() && isFileExtensionHandled(forFile);
  }
  public boolean checkFileExists()
  {
    boolean exists = new File(diffProgram).exists();
    if (REPORT_MISSING_FILES && !exists)
    {
      System.out.println(String.format("%s can't find '%s'", this.getClass().getSimpleName(), diffProgram));
    }
    return exists;
  }
  public boolean isFileExtensionHandled(String forFile)
  {
    return isFileExtensionValid(forFile, validExtensions);
  }
  public static boolean isFileExtensionValid(String forFile, List<String> validExtensionsWithDot)
  {
    String extensionWithDot = FileUtils.getExtensionWithDot(forFile);
    return validExtensionsWithDot.contains(extensionWithDot);
  }
}