version.txt at project root is packaged

Author: AdamBien

src/main/java/airhacks/App.java

@@ -1,6 +1,7 @@
 package airhacks;
 
 import java.io.IOException;
+import java.nio.file.Path;
 
 import java.util.Optional;
 
@@ -54,7 +55,7 @@ static void build(AppArguments arguments) throws IOException {
         var jarDirectory = arguments.jarDirectory();
         var jarFileName = arguments.jarFileName();
 
-        Packer.createJAR(classesDirectory, resourcesDirectory, jarDirectory, jarFileName,relativeMainClass);
+        Packer.createJAR(Path.of("."), classesDirectory, resourcesDirectory, jarDirectory, jarFileName,relativeMainClass);
         if (arguments.isClassesDirTemporary()) {
             Cleaner.cleanClasses(classesDirectory);
         }

src/main/java/airhacks/zb/packer/control/Packer.java

@@ -17,12 +17,13 @@ public interface Packer {
 
     String VERSION_FILE = "version.txt";
 
-    static void createJAR(Path rootClassesDirectory, Optional<Path> rootResourcesDirectory, Path rootJARDirectory, String jarFileName, Optional<Path> mainClass) throws IOException {
+    static void createJAR(Path projectRoot, Path rootClassesDirectory, Optional<Path> rootResourcesDirectory, Path rootJARDirectory, String jarFileName, Optional<Path> mainClass) throws IOException {
         var jarFile = rootJARDirectory.resolve(jarFileName);
         Files.createDirectories(rootJARDirectory);
         Files.deleteIfExists(jarFile);
 
-        var version = rootResourcesDirectory.flatMap(Packer::readVersion);
+        var versionFile = locateVersionFile(projectRoot, rootResourcesDirectory);
+        var version = versionFile.flatMap(Packer::readVersionContent);
 
         try (var fos = Files.newOutputStream(jarFile, StandardOpenOption.CREATE_NEW);
              var jos = new JarOutputStream(fos)) {
@@ -37,24 +38,44 @@ static void createJAR(Path rootClassesDirectory, Optional<Path> rootResourcesDir
                 var dir = rootResourcesDirectory.get();
                 try (var paths = Files.walk(dir)) {
                     paths.filter(Files::isRegularFile)
+                         .filter(path -> !path.equals(dir.resolve(VERSION_FILE)))
                          .forEach(path -> addEntry(dir, jos, path));
                 }
             }
+            versionFile.ifPresent(file -> addVersionEntry(jos, file));
         }
     }
 
-    static Optional<String> readVersion(Path resourcesDirectory) {
-        var versionFile = resourcesDirectory.resolve(VERSION_FILE);
-        if (!Files.isRegularFile(versionFile)) {
-            return Optional.empty();
+    static Optional<Path> locateVersionFile(Path projectRoot, Optional<Path> resourcesDirectory) {
+        var rootCandidate = projectRoot.resolve(VERSION_FILE);
+        if (Files.isRegularFile(rootCandidate)) {
+            return Optional.of(rootCandidate);
         }
+        return resourcesDirectory
+                .map(dir -> dir.resolve(VERSION_FILE))
+                .filter(Files::isRegularFile);
+    }
+
+    static Optional<String> readVersion(Path projectRoot, Optional<Path> resourcesDirectory) {
+        return locateVersionFile(projectRoot, resourcesDirectory).flatMap(Packer::readVersionContent);
+    }
+
+    static Optional<String> readVersionContent(Path versionFile) {
         try {
             return Optional.of(Files.readString(versionFile).trim());
         } catch (IOException e) {
             return Optional.empty();
         }
     }
 
+    static void addVersionEntry(JarOutputStream jos, Path versionFile) {
+        try {
+            addEntry(jos, Path.of(VERSION_FILE), Files.readAllBytes(versionFile));
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to add version.txt to JAR: " + versionFile, e);
+        }
+    }
+
     static void addManifest(Path rootClassesDirectory, JarOutputStream jos, Path mainClass, Optional<String> version) {
         var javaPackage = pathToJavaPackage(mainClass);
         var fullyQualifiedClassName = javaPackage.replace(".java", "");

src/main/resources/version.txt

@@ -1 +1 @@
-2026.05.26.01
+2026.05.26.02

src/test/java/airhacks/zb/packer/control/PackerTest.java

@@ -31,15 +31,30 @@ void pathToJavaPackage() {
     }
 
     @Test
-    void readVersionWhenPresent(@TempDir Path resources) throws IOException {
+    void readVersionFromResourcesWhenRootMissing(@TempDir Path projectRoot, @TempDir Path resources) throws IOException {
         Files.writeString(resources.resolve("version.txt"), "2026.04.26.01\n");
-        var version = Packer.readVersion(resources);
+        var version = Packer.readVersion(projectRoot, Optional.of(resources));
         assertThat(version).contains("2026.04.26.01");
     }
 
     @Test
-    void readVersionWhenAbsent(@TempDir Path resources) {
-        var version = Packer.readVersion(resources);
+    void readVersionFromProjectRootPreferredOverResources(@TempDir Path projectRoot, @TempDir Path resources) throws IOException {
+        Files.writeString(projectRoot.resolve("version.txt"), "2026.05.26.01\n");
+        Files.writeString(resources.resolve("version.txt"), "2026.04.26.01\n");
+        var version = Packer.readVersion(projectRoot, Optional.of(resources));
+        assertThat(version).contains("2026.05.26.01");
+    }
+
+    @Test
+    void readVersionFromProjectRootWhenNoResources(@TempDir Path projectRoot) throws IOException {
+        Files.writeString(projectRoot.resolve("version.txt"), "2026.05.26.01\n");
+        var version = Packer.readVersion(projectRoot, Optional.empty());
+        assertThat(version).contains("2026.05.26.01");
+    }
+
+    @Test
+    void readVersionWhenAbsent(@TempDir Path projectRoot, @TempDir Path resources) {
+        var version = Packer.readVersion(projectRoot, Optional.of(resources));
         assertThat(version).isEmpty();
     }