Utility class that diffs 2 maven test run logs and outputs the percentage difference in the run times on test classes that are found in both files

DiffMvnTest.scala

import scala.Option.option2Iterable
import scala.io.Source

/**
 * Utility class that diffs 2 maven test run logs and outputs the percentage difference in the run times on test classes that are found in both files
 *
 * How to run
 *
 * - run first test on the reference
 *      mvn clean install > before.log
 *
 * - change the setup and run again the maven test suite
 *      mvn clean install > after.log
 *
 * - Use the 2 produced logs as an input for the DiffMvnTest
 *      scala DiffMvnTest.scala before.log after.log
 *
 *    and you'll get a report that shows you the percentage difference between tests that are in both log files
 *      org.apache.jackrabbit.oak.api.QueryTest,1(0.06),1(0.03),-50%
 *
 * This means
 *  - the name of the test is 'org.apache.jackrabbit.oak.api.QueryTest'
 *  - the first run had 1 test that executed in 0.06 sec
 *  - the second run had 1 test that executed in 0.03 sec
 *  - the percentage difference is -50%
 *
 * Under the hood the program greps the input file for output like the following:
 *
 * ....
 * Running org.apache.jackrabbit.mk.tests.MkConcurrentAddNodes1CommitTest
 * [possible sysout garbage in between]
 * Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.562 sec
 * ....
 *
 * Next it will build a map of known test cases which it then will try to merge with the map build using the second input file.
 *
 *
 * Tested with Scala 2.10
 *
 */
object DiffMvnTest {

  def diff(file1: String, file2: String) = {
    val m1 = aggregate(file1).toMap;
    val m2 = aggregate(file2).toMap;
    val diffs = for (i1 ← m1; i2 ← m2.get(i1._1)) yield {
      val delta = if (i2._5 != 0 && i1._2._5 != 0) {
        (i2._5 * 100 / i1._2._5).toInt - 100;
      } else {
        0
      }
      new Tuple4(i1._1, i1._2, i2, delta);
    }
    diffs
  }

  def aggregate(file: String) = {
    val firstToken = "Running ";
    val secondToken = "Tests run: ";

    grep(Source.fromFile(file).getLines(), firstToken, secondToken).map(p ⇒ {
      val test = p._1.substring(firstToken.length());

      //  Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.562 sec
      val fragments = p._2.split(", ");
      val tests = fragments(0).substring("Tests run: ".length()).toInt;
      val failures = fragments(1).substring("Failures: ".length()).toInt;
      val errors = fragments(2).substring("Errors: ".length()).toInt;
      val skipped = fragments(3).substring("Skipped: ".length()).toInt;
      val timeRaw = fragments(4).substring("Time elapsed: ".length(), fragments(4).indexOf(" sec")).toDouble;
      val time = (math floor timeRaw * 100) / 100;
      val results = (tests, failures, errors, skipped, time);
      new Pair(test, results);
    });
  }

  def grep(lines: Iterator[String], firstToken: String, secondToken: String): Iterator[Pair[String, String]] = {
    for (x ← lines; l ← findFirst(lines, firstToken); p ← findFirst(lines, secondToken))
      yield new Pair(l, p);
  }

  def findFirst(lines: Iterator[String], starts: String): Option[String] = {
    for (l ← lines if l.startsWith(starts)) {
      return Some(l);
    }
    return None;
  }

  // -------------- print methods -----------------------

  def asPlainText(file1: String, file2: String) = {
    println("Test Name, First Run, Second Run, %Diff");
    diff(file1, file2).toSeq.sortBy(e ⇒ (-e._4, e._1)).foreach(i ⇒ {
      println(i._1 + "," + i._2._1 + "(" + i._2._5 + ")," + i._3._1 + "(" + i._3._5 + ")," + i._4 + "%");
    });
  }

  def asJiraTable(file1: String, file2: String) = {
    println("||Test Name||First Run||Second Run,||%Diff||");
    diff(file1, file2).toSeq.sortBy(e ⇒ (-e._4, e._1)).foreach(i ⇒ {
      println("|" + i._1 + "|" + i._2._1 + "(" + i._2._5 + ")|" + i._3._1 + "(" + i._3._5 + ")|" + i._4 + "%|");
    });
  }

  def main(args: Array[String]) {
    if (args.length != 2 && args.length != 3) {
      println("To run");
      println("    scala DiffMvnTest.scala filename1 filename2 [1]");
      println("");
      println("DiffMvnTest args:");
      println("  filename1, filename2 are paths to the input files (logs generated by running 'mvn test > l.log'");
      println("  [1] is an optional flag controlling the output formatting - use '1' for ");
      println("     - use '1' for a JIRA style table");
      println("     - use '0' or nothing for plain text output");
      return;
    }
    if (args.length == 3 && "1".equals(args(2))) {
      asJiraTable(args(0), args(1));
    } else {
      asPlainText(args(0), args(1));
    }
  }
}