MMF-2692 Initial git blame command implementation

2 files changed, 226 insertions, 0 deletions

diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scm/git/GitBlameCommand.java b/sonar-scanner-engine/src/main/java/org/sonar/scm/git/GitBlameCommand.java
new file mode 100644
index 00000000000..856a1503ec9
--- /dev/null
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scm/git/GitBlameCommand.java
@@ -0,0 +1,175 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2022 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.scm.git;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+import org.apache.commons.lang.StringUtils;
+import org.sonar.api.batch.scm.BlameLine;
+
+import static java.util.Objects.requireNonNull;
+
+public class GitBlameCommand {
+  private static final String AUTHOR = "author";
+  private static final String COMMIT = "commit";
+  private static final String TIMESTAMP = "timestamp";
+  private static final String TIMEZONE = "timezone";
+  private static final String LINE = "line";
+
+  private static final String GIT_COMMAND = "git";
+  private static final String BLAME_COMMAND = "blame";
+  private static final String BLAME_LONG_FLAG = "-l";
+  private static final String BLAME_SHOW_EMAIL_FLAG = "--show-email";
+  private static final String BLAME_TIMESTAMP_FLAG = "-t";
+
+  public static List<BlameLine> executeCommand(Path directory, String... command) throws IOException, InterruptedException {
+    requireNonNull(directory, "directory");
+
+    if (!Files.exists(directory)) {
+      throw new RuntimeException("Directory does not exist, unable to run git operations:'" + directory + "'");
+    }
+
+    ProcessBuilder pb = new ProcessBuilder()
+      .command(command)
+      .directory(directory.toFile());
+
+    Process p = pb.start();
+
+    List<String> commandOutput = new ArrayList<>();
+    InputStream processStdOutput = p.getInputStream();
+
+    try (BufferedReader br = new BufferedReader(new InputStreamReader(processStdOutput))) {
+        String outputLine;
+
+        while ((outputLine = br.readLine()) != null) {
+          commandOutput.add(outputLine);
+        }
+
+        int exit = p.waitFor();
+
+        if (exit != 0) {
+          throw new AssertionError(String.format("Command execution exited with code: %d", exit));
+        }
+
+    } catch (Exception e) {
+      e.printStackTrace();
+    } finally {
+      p.destroy();
+    }
+
+    return commandOutput
+      .stream()
+      .map(GitBlameCommand::parseBlameLine)
+      .collect(Collectors.toList());
+  }
+
+  private static Map<String, String> getBlameAuthoringData(String blameLine) {
+    String[] blameLineFormatted = blameLine.trim().split("\\s+", 2);
+
+    String commit = blameLineFormatted[0];
+
+    if (commit.length() != 40) {
+      throw new IllegalStateException(String.format("Failed to fetch correct commit hash, must be of length 40: %s", commit));
+    }
+
+    String authoringData = StringUtils.substringBetween(blameLineFormatted[1], "(", ")");
+    String[] authoringDataFormatted = authoringData.trim().split("\\s+", 4);
+
+    String author = StringUtils.substringBetween(authoringDataFormatted[0], "<", ">");
+    String timestamp = authoringDataFormatted[1];
+    String timezone = authoringDataFormatted[2];
+    String line = authoringDataFormatted[3];
+
+    Map<String, String> blameData = new HashMap<>();
+
+    blameData.put(COMMIT, commit);
+    blameData.put(AUTHOR, author);
+    blameData.put(TIMESTAMP, timestamp);
+    blameData.put(TIMEZONE, timezone);
+    blameData.put(LINE, line);
+
+    return blameData;
+  }
+
+  private static BlameLine parseBlameLine(String blameLine) {
+    Map<String, String> blameData = getBlameAuthoringData(blameLine);
+
+    return new BlameLine()
+      .date(new Date(Long.parseLong(blameData.get(TIMESTAMP)))) // should also take timezone into consideration
+      .revision(blameData.get(COMMIT))
+      .author(blameData.get(AUTHOR));
+  }
+
+  public static void gitInit(Path directory) throws IOException, InterruptedException {
+    executeCommand(directory, "git", "init");
+  }
+
+  public static void gitStage(Path directory) throws IOException, InterruptedException {
+    executeCommand(directory, "git", "add", "-A");
+  }
+
+  public static void gitCommit(Path directory, String message) throws IOException, InterruptedException {
+    executeCommand(directory, GIT_COMMAND, COMMIT, "-m", message);
+  }
+
+  public static void gitClone(Path directory, String originUrl) throws IOException, InterruptedException {
+    executeCommand(directory.getParent(), "git", "clone", originUrl, directory.getFileName().toString());
+  }
+
+  public static List<BlameLine> gitBlame(Path directory, String fileName) throws IOException, InterruptedException {
+    return executeCommand(directory, GIT_COMMAND, BLAME_COMMAND, BLAME_LONG_FLAG, BLAME_SHOW_EMAIL_FLAG, BLAME_TIMESTAMP_FLAG, fileName);
+  }
+
+  private static class StreamGobbler extends Thread {
+    private final InputStream is;
+    private final String type;
+
+    private StreamGobbler(InputStream is, String type) {
+      this.is = is;
+      this.type = type;
+    }
+
+    @Override
+    public void run() {
+      try (BufferedReader br = new BufferedReader(new InputStreamReader(is));) {
+        List<String> commandOutput = new ArrayList<>();
+        String outputLine;
+
+        while ((outputLine = br.readLine()) != null) {
+          commandOutput.add(outputLine);
+          System.out.println(type + "> " + outputLine);
+        }
+      } catch (IOException ioe) {
+        ioe.printStackTrace();
+      }
+    }
+  }
+
+}
diff --git a/sonar-scanner-engine/src/test/java/org/sonar/scm/git/GitBlameCommandTest.java b/sonar-scanner-engine/src/test/java/org/sonar/scm/git/GitBlameCommandTest.java
new file mode 100644
index 00000000000..2785ceeb7ad
--- /dev/null
+++ b/sonar-scanner-engine/src/test/java/org/sonar/scm/git/GitBlameCommandTest.java
@@ -0,0 +1,51 @@
+package org.sonar.scm.git;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+import org.junit.Test;
+import org.sonar.api.batch.scm.BlameLine;
+
+import static org.sonar.scm.git.GitBlameCommand.gitBlame;
+import static org.sonar.scm.git.GitBlameCommand.gitClone;
+import static org.sonar.scm.git.GitBlameCommand.gitCommit;
+import static org.sonar.scm.git.GitBlameCommand.gitInit;
+import static org.sonar.scm.git.GitBlameCommand.gitStage;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class GitBlameCommandTest {
+  private static final String ORIGIN_URL = "https://github.com/klaussinani/taskbook.git";
+
+  @Test
+  public void testBlame() throws IOException, InterruptedException {
+    String tmpDirectory = Files.createTempDirectory("tmpDirectory").toFile().getAbsolutePath();
+    Path directory = Paths.get(tmpDirectory);
+    gitClone(directory, ORIGIN_URL);
+    List<BlameLine> blameOutput = gitBlame(directory, "readme.md");
+    assertThat(blameOutput.size()).isEqualTo(378);
+  }
+
+  @Test
+  public void initAndAddFile() throws IOException, InterruptedException {
+    String tmpDirectory = Files.createTempDirectory("tmpDirectory").toFile().getAbsolutePath();
+    Path directory = Paths.get(tmpDirectory);
+    Files.createDirectories(directory);
+    gitInit(directory);
+    Files.write(directory.resolve("bar.c"), new byte[0]);
+    gitStage(directory);
+    gitCommit(directory, "Add bar.c");
+  }
+
+  @Test
+  public void cloneAndAddFile() throws IOException, InterruptedException {
+    String tmpDirectory = Files.createTempDirectory("tmpDirectory").toFile().getAbsolutePath();
+    Path directory = Paths.get(tmpDirectory);
+    gitClone(directory, ORIGIN_URL);
+    Files.write(directory.resolve("bar.c"), new byte[0]);
+    gitStage(directory);
+    gitCommit(directory, "Add bar.c");
+    // gitPush(directory); // don't push
+  }
+}
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