Function stagingTest

test/tests/stage.js:27–168

(isUnstaged, newFileContent, discarding)

  });

  function stagingTest(isUnstaged, newFileContent, discarding) {
    var fileContent = newFileContent ||
                      "One line of text\n" +
                      "Two lines of text\n"+
                      "Three lines of text\n"+
                      "Four lines of text\n"+
                      "Five lines of text\n"+
                      "Six lines of text\n"+
                      "Seven lines of text\n"+
                      "Eight lines of text\n"+
                      "Nine lines of text\n"+
                      "Ten lines of text\n"+
                      "Eleven lines of text\n"+
                      "Twelve lines of text\n"+
                      "Thirteen lines of text\n"+
                      "Fourteen lines of text\n"+
                      "Fifteen lines of text\n"+
                      "Sixteen lines of text\n"+
                      "Seventeen lines of text\n"+
                      "Eighteen lines of text\n"+
                      "Nineteen lines of text\n"+
                      "Twenty lines of text\n";
    var fileName = "stagedLinesTest.txt";
    var expectedContent;
    var workingDirFile;
    var getDiffFunction;

    if (!isUnstaged || discarding) {
      expectedContent = fileContent.replace("Three", "Changed three")
                            .replace("Seventeen", "Changed seventeen");
      workingDirFile = expectedContent.replace("Fifteen", "Changed fifteen");
    }
    else {
      expectedContent = fileContent.replace("Fifteen", "Changed fifteen");
      workingDirFile = expectedContent.replace("Three", "Changed three")
                            .replace("Seventeen", "Changed seventeen");
    }

    if (isUnstaged) {
      getDiffFunction = function() {
        return test.repository.refreshIndex()
          .then(function(index) {
            return NodeGit.Diff.indexToWorkdir(
              test.repository,
              index,
              {
                flags:
                  NodeGit.Diff.OPTION.SHOW_UNTRACKED_CONTENT |
                  NodeGit.Diff.OPTION.RECURSE_UNTRACKED_DIRS
              }
            );
          });
      };
    }
    else {
      getDiffFunction = function() {
        return RepoUtils.addFileToIndex(test.repository, fileName)
          .then(function() {