Strip build dependent comments in Play compilers generated files

src/docs/asciidoc/10-plugin-conventions.adoc

@@ -8,4 +8,6 @@ include::13-tasks.adoc[]
 
 include::14-source-sets.adoc[]
 
-include::15-dependency-configurations.adoc[]
+include::15-dependency-configurations.adoc[]
+
+include::16-routes-comments.adoc[]

src/docs/asciidoc/16-routes-comments.adoc

@@ -0,0 +1,4 @@
+=== Generated routes files comments
+
+Routes files generated by the compiler contain comments which are changing across builds (absolute path and date depending on the framework version), this prevents tasks using those files as inputs to benefit from build cache.
+The plugin is post-processing those files to remove timestamp and convert absolute paths to relative paths.

src/docs/asciidoc/50-changes.adoc

@@ -1,5 +1,9 @@
 == Change Log
 
+[discrete]
+=== v0.14 (TBD)
+* Add configuration to post-process routes comments ({uri-github-issues}/109[issue #109]).
+
 [discrete]
 === v0.13 (2023-01-24)
 * Remove usage of internal Gradle API org.gradle.api.internal.artifacts.dsl.LazyPublishArtifact

src/integTest/groovy/org/gradle/playframework/tasks/AbstractRoutesCompileIntegrationTest.groovy

@@ -6,8 +6,11 @@ import org.gradle.testkit.runner.TaskOutcome
 import org.gradle.util.VersionNumber
 import org.junit.Assume
 
+import java.nio.charset.StandardCharsets
+
 import static org.gradle.playframework.fixtures.Repositories.playRepositories
 import static org.gradle.playframework.fixtures.file.FileFixtures.assertContentsHaveChangedSince
+import static org.gradle.playframework.fixtures.file.FileFixtures.assertModificationTimeHasChangedSince
 import static org.gradle.playframework.fixtures.file.FileFixtures.snapshot
 import static org.gradle.playframework.plugins.PlayRoutesPlugin.ROUTES_COMPILE_TASK_NAME
 
@@ -121,7 +124,7 @@ GET     /newroute                          ${controllers()}.Application.index()
 
         and:
         assertContentsHaveChangedSince(scalaRoutesFileSnapshot, getScalaRoutesFile())
-        assertContentsHaveChangedSince(javaRoutesFileSnapshot, getJavaRoutesFile())
+        assertModificationTimeHasChangedSince(javaRoutesFileSnapshot, getJavaRoutesFile())
         assertContentsHaveChangedSince(reverseRoutesFileSnapshot, getReverseRoutesFile())
 
         when:
@@ -259,4 +262,18 @@ $ROUTES_COMPILE_TASK_NAME {
         new File(destinationDir, getReverseRoutesFileName('', '')).text.contains("extra.package")
         new File(destinationDir, getScalaRoutesFileName('', '')).text.contains("extra.package")
     }
+
+    def "post-process generated comments"() {
+        given:
+        withRoutesTemplate()
+        when:
+        build(ROUTES_COMPILE_TASK_NAME)
+        then:
+        createRouteFileList().each {
+            def generatedFile = new File(destinationDir, it)
+            assert generatedFile.isFile()
+            assert generatedFile.getText(StandardCharsets.UTF_8.toString()).contains("// @(SOURCE):conf/routes")
+            assert !generatedFile.getText(StandardCharsets.UTF_8.toString()).contains("// @(DATE)")
+        }
+    }
 }

src/integTestFixtures/groovy/org/gradle/playframework/fixtures/file/FileFixtures.groovy

@@ -32,6 +32,11 @@ final class FileFixtures {
         assertNotEquals(oldSnapshot.hash, now.hash)
     }
 
+    static void assertModificationTimeHasChangedSince(Snapshot oldSnapshot, File file) {
+        Snapshot now = snapshot(file)
+        assertNotEquals(oldSnapshot.modTime, now.modTime)
+    }
+
     private static File assertIsFile(File file) {
         assertTrue(file.isFile())
     }

src/main/java/org/gradle/playframework/tasks/RoutesCompile.java

@@ -2,7 +2,6 @@
 
 import org.gradle.api.Action;
 import org.gradle.api.file.ConfigurableFileCollection;
-import org.gradle.api.file.Directory;
 import org.gradle.api.file.DirectoryProperty;
 import org.gradle.api.file.FileTree;
 import org.gradle.api.provider.ListProperty;
@@ -29,6 +28,7 @@
 import org.gradle.workers.WorkerExecutor;
 
 import javax.inject.Inject;
+import java.io.File;
 
 /**
  * Task for compiling routes templates into Scala code.
@@ -52,6 +52,7 @@ public class RoutesCompile extends SourceTask {
     private final Property<PlayPlatform> platform;
     private final Property<Boolean> injectedRoutesGenerator;
     private final ConfigurableFileCollection routesCompilerClasspath;
+    private final File projectDir;
 
     @Inject
     public RoutesCompile(WorkerExecutor workerExecutor) {
@@ -66,6 +67,7 @@ public RoutesCompile(WorkerExecutor workerExecutor) {
         this.injectedRoutesGenerator = getProject().getObjects().property(Boolean.class);
         this.injectedRoutesGenerator.set(false);
         this.routesCompilerClasspath = getProject().files();
+        this.projectDir = getProject().getProjectDir();
     }
 
     /**
@@ -105,7 +107,7 @@ public ConfigurableFileCollection getRoutesCompilerClasspath() {
     @TaskAction
     @SuppressWarnings("Convert2Lambda")
     void compile() {
-        RoutesCompileSpec spec = new DefaultRoutesCompileSpec(getSource().getFiles(), getOutputDirectory().get().getAsFile(), isJavaProject(), getNamespaceReverseRouter().get(), getGenerateReverseRoutes().get(), getInjectedRoutesGenerator().get(), getAdditionalImports().get());
+        RoutesCompileSpec spec = new DefaultRoutesCompileSpec(getSource().getFiles(), getOutputDirectory().get().getAsFile(), isJavaProject(), getNamespaceReverseRouter().get(), getGenerateReverseRoutes().get(), getInjectedRoutesGenerator().get(), getAdditionalImports().get(), getProjectDir());
 
         if (GradleVersion.current().compareTo(GradleVersion.version("5.6")) < 0) {
             workerExecutor.submit(RoutesCompileRunnable.class, workerConfiguration -> {
@@ -177,4 +179,15 @@ public Property<Boolean> getGenerateReverseRoutes() {
     public Property<Boolean> getInjectedRoutesGenerator() {
         return injectedRoutesGenerator;
     }
+
+    /**
+     * The project directory is used to relativize the route source folder
+     * when post-processing the generated routes files.
+     *
+     * @return The project directory.
+     */
+    @Internal
+    public File getProjectDir() {
+        return projectDir;
+    }
 }

src/main/java/org/gradle/playframework/tools/internal/routes/DefaultRoutesCompileSpec.java

@@ -11,15 +11,17 @@ public class DefaultRoutesCompileSpec implements RoutesCompileSpec {
     private final boolean generateReverseRoutes;
     private final boolean injectedRoutesGenerator;
     private final Collection<String> additionalImports;
+    private final File projectDir;
 
-    public DefaultRoutesCompileSpec(Iterable<File> sourceFiles, File outputDirectory, boolean javaProject, boolean namespaceReverseRouter, boolean generateReverseRoutes, boolean injectedRoutesGenerator, Collection<String> additionalImports) {
+    public DefaultRoutesCompileSpec(Iterable<File> sourceFiles, File outputDirectory, boolean javaProject, boolean namespaceReverseRouter, boolean generateReverseRoutes, boolean injectedRoutesGenerator, Collection<String> additionalImports, File projectDir) {
         this.sourceFiles = sourceFiles;
         this.outputDirectory = outputDirectory;
         this.javaProject = javaProject;
         this.namespaceReverseRouter = namespaceReverseRouter;
         this.generateReverseRoutes = generateReverseRoutes;
         this.injectedRoutesGenerator = injectedRoutesGenerator;
         this.additionalImports = additionalImports;
+        this.projectDir = projectDir;
     }
 
     @Override
@@ -56,4 +58,9 @@ public boolean isInjectedRoutesGenerator() {
     public Collection<String> getAdditionalImports() {
         return additionalImports;
     }
+
+    @Override
+    public File getProjectDir() {
+        return projectDir;
+    }
 }

src/main/java/org/gradle/playframework/tools/internal/routes/DefaultRoutesPostProcessor.java

@@ -0,0 +1,52 @@
+package org.gradle.playframework.tools.internal.routes;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.stream.Stream;
+
+class DefaultRoutesPostProcessor implements Serializable {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultRoutesPostProcessor.class);
+
+    void execute(RoutesCompileSpec spec) {
+        String sourceReplacementString = getSourceReplacementString(spec.getSources(), spec.getProjectDir());
+
+        try (Stream<Path> stream = Files.find(spec.getDestinationDir().toPath(), Integer.MAX_VALUE, (filePath, fileAttr) -> fileAttr.isRegularFile())) {
+            stream.forEach(routeFile -> process(routeFile, sourceReplacementString));
+        } catch (IOException e) {
+            LOGGER.warn("Unable to post-process routes", e);
+        }
+    }
+
+    private String getSourceReplacementString(Iterable<File> sources, File projectDir) {
+        String sourceReplacementString = "";
+
+        if(sources.iterator().hasNext()) {
+            File sourceFile = sources.iterator().next();
+            sourceReplacementString = "// @(SOURCE):" +
+                    projectDir.toURI().relativize(sourceFile.toURI())
+                            .getPath()
+                            .replace(File.separator, "/");
+        }
+
+        return sourceReplacementString;
+    }
+
+    private void process(Path routeFile, String sourceReplacementString) {
+        try {
+            String content = new String(Files.readAllBytes(routeFile), StandardCharsets.UTF_8);
+            content = content.replaceAll("(?m)^// @(SOURCE):.*", sourceReplacementString);
+            content = content.replaceAll("(?m)^// @(DATE):.*", "");
+            Files.write(routeFile, content.getBytes(StandardCharsets.UTF_8));
+        } catch (IOException e) {
+            LOGGER.warn(String.format("Unable to post-process route file %s", routeFile.getFileName()), e);
+        }
+    }
+}

src/main/java/org/gradle/playframework/tools/internal/routes/RoutesCompileSpec.java

@@ -18,4 +18,6 @@ public interface RoutesCompileSpec extends PlayCompileSpec, Serializable {
     boolean isInjectedRoutesGenerator();
 
     Collection<String> getAdditionalImports();
+
+    File getProjectDir();
 }

src/main/java/org/gradle/playframework/tools/internal/routes/RoutesCompiler.java

@@ -12,8 +12,11 @@
 public class RoutesCompiler implements Compiler<RoutesCompileSpec>, Serializable {
     private final VersionedRoutesCompilerAdapter adapter;
 
+    private final DefaultRoutesPostProcessor postProcessor;
+
     public RoutesCompiler(VersionedRoutesCompilerAdapter adapter) {
         this.adapter = adapter;
+        this.postProcessor = new DefaultRoutesPostProcessor();
     }
 
     @Override
@@ -42,6 +45,9 @@ public WorkResult execute(RoutesCompileSpec spec) {
             didWork = ret || didWork;
         }
 
+        // Post-process routes files
+        postProcessor.execute(spec);
+
         return WorkResults.didWork(didWork);
     }