Enable reproducible builds by suppressing date comment in properties

core/pom.xml

@@ -48,5 +48,10 @@
             <groupId>com.google.code.findbugs</groupId>
             <artifactId>jsr305</artifactId>
         </dependency>
+        <dependency>
+            <groupId>nu.studer</groupId>
+            <artifactId>java-ordered-properties</artifactId>
+            <version>1.0.4</version>
+        </dependency>
     </dependencies>
-</project>
+</project>

core/src/main/java/pl/project13/core/PropertiesFileGenerator.java

@@ -19,14 +19,15 @@
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import nu.studer.java.util.OrderedProperties;
 import org.sonatype.plexus.build.incremental.BuildContext;
 import pl.project13.core.log.LoggerBridge;
-import pl.project13.core.util.SortedProperties;
 
 import javax.annotation.Nonnull;
 import java.io.*;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
@@ -86,8 +87,11 @@ public void maybeGeneratePropertiesFile(@Nonnull Properties localProperties, Fil
       if (shouldGenerate) {
         Files.createDirectories(gitPropsFile.getParentFile().toPath());
         try (OutputStream outputStream = new FileOutputStream(gitPropsFile)) {
-          SortedProperties sortedLocalProperties = new SortedProperties();
-          sortedLocalProperties.putAll(localProperties);
+          OrderedProperties sortedLocalProperties = new OrderedProperties.OrderedPropertiesBuilder()
+                  .withSuppressDateInComment(true)
+                  .withOrdering(Comparator.nullsLast(Comparator.naturalOrder()))
+                  .build();
+          localProperties.forEach((key, value) -> sortedLocalProperties.setProperty((String) key, (String) value));
           if (isJsonFormat) {
             try (Writer outputWriter = new OutputStreamWriter(outputStream, sourceCharset)) {
               log.info("Writing json file to [{}] (for module {})...", gitPropsFile.getAbsolutePath(), projectName);

maven/src/test/java/pl/project13/core/PropertiesFileGeneratorTest.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of git-commit-id-plugin by Konrad 'ktoso' Malawski <[email protected]>
+ *
+ * git-commit-id-plugin 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.
+ *
+ * git-commit-id-plugin 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with git-commit-id-plugin.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package pl.project13.core;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.sonatype.plexus.build.incremental.BuildContext;
+import org.sonatype.plexus.build.incremental.DefaultBuildContext;
+import pl.project13.core.log.LoggerBridge;
+import pl.project13.core.log.StdOutLoggerBridge;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Properties;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.Assert.assertEquals;
+
+public class PropertiesFileGeneratorTest {
+  @Rule
+  public final TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  private final LoggerBridge loggerBridge = new StdOutLoggerBridge(false);
+  private final BuildContext buildContext = new DefaultBuildContext();
+
+  private PropertiesFileGenerator propertiesFileGenerator;
+
+  @Before
+  public void setUp() {
+    propertiesFileGenerator = new PropertiesFileGenerator(loggerBridge, buildContext, "properties", "", "test");
+  }
+
+  @Test
+  public void generatedPropertiesFileDoesNotContainDateComment() throws GitCommitIdExecutionException, IOException {
+    Properties properties = new Properties();
+    properties.put(GitCommitPropertyConstant.COMMIT_ID_FULL, "b5993378ffadd1f84dc8da220b9204d157ec0f29");
+    properties.put(GitCommitPropertyConstant.BRANCH, "develop");
+
+    Path propertiesPath = temporaryFolder.getRoot().toPath().resolve("git.properties");
+    propertiesFileGenerator.maybeGeneratePropertiesFile(properties, temporaryFolder.getRoot(), propertiesPath.getFileName().toString(), UTF_8);
+
+    byte[] bytes = Files.readAllBytes(propertiesPath);
+    String actualContent = new String(bytes, UTF_8);
+    String expectedContent = "#Generated by Git-Commit-Id-Plugin\n"
+        + "branch=develop\n"
+        + "commit.id.full=b5993378ffadd1f84dc8da220b9204d157ec0f29\n";
+    assertEquals(expectedContent, actualContent);
+  }
+}