Make the plugin compatible with Palantir's consistent versions plugin

README.md

@@ -46,8 +46,8 @@ build script. These options are as follows:
 * `scoverageVersion = <String>` (default `"1.4.1"`): The version of the scoverage scalac plugin. This (gradle) plugin
 should be compatible with all 1+ versions.
 
-* `scoverageScalaVersion = <String>` (default `"2.12"`): The scala version of the scoverage scalac plugin. This will
-be overridden by the version of the `scala-library` compile dependency (if the dependency is configured).
+* `scoverageScalaVersion = <String>` (default `"2.12"`): The scala version of the scoverage scalac plugin. This
+overrides the version of the `scala-library` compile dependency (if the dependency is configured).
 
 * `coverageOutputCobertura = <boolean>` (default `true`): Enables/disables cobertura.xml file generation (for both aggregated and non-aggregated reports).
 
@@ -115,6 +115,13 @@ it is possible to only compile the code with the scoverage scalac plugin, thus r
 In order to do so, simply add the arguments `-x compileScala` to the gradle execution.
 For example: `gradle reportScoverage -x compileScala`.
 
+
+### Compatibility with Consistent Versions Plugin
+
+In order for the plugin to work alongside [Palantir's consistent versions plugin](https://github.com/palantir/gradle-consistent-versions),
+the Scala version must be manually configured (via `scoverageScalaVersion`); otherwise, the plugin will attempt to
+resolve the compilation classpath, which is prohibited by the versions plugin.
+
 Migration to 4.x
 ----------------
 

src/functionalTest/java/org/scoverage/DetectScalaLibraryTest.java

@@ -7,22 +7,40 @@
 
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.List;
+import java.util.stream.Stream;
 
 @RunWith(Parameterized.class)
 public class DetectScalaLibraryTest extends ScoverageFunctionalTest {
 
     private static final String SCALA_VERSION = "2.12";
     private static final String SCALA_LIBRARY_PARAMETER = "-PdetectedScalaLibraryVersion=";
 
-    private static final String EXPECTED_OUTPUT_A = "Detected scala library in compilation classpath";
-    private static final String EXPECTED_OUTPUT_B = "Using scoverage scalac plugin version '" + SCALA_VERSION;
+    private static final String EXPECTED_OUTPUT_CONFIGURED_VERSION = "Using configured Scala version";
+    private static final String EXPECTED_OUTPUT_DETECTED_VERSION = "Detected scala library in compilation classpath";
+    private static final String EXPECTED_OUTPUT_USING = "Using scoverage scalac plugin version '" + SCALA_VERSION;
 
     @Parameterized.Parameter(0)
     public String projectDir;
 
+    @Parameterized.Parameter(1)
+    public String[] subVersions;
+
+    @Parameterized.Parameter(2)
+    public boolean detect;
+
+    @Parameterized.Parameter(3)
+    public String[] additionalParameters;
+
     @Parameterized.Parameters(name = "{index}: Project {0} ")
     public static Collection<Object[]> data() {
-        Object[][] data = new Object[][]{{"/compile"}, {"/compileOnly"}, {"/implementation"}, {"/dependency-management"}};
+        Object[][] data = new Object[][]{
+                {"/compile", new String[] {".0", ".+"}, true, new String[0]},
+                {"/compileOnly", new String[] {".0", ".+"}, true, new String[0]},
+                {"/implementation", new String[] {".0", ".+"}, true, new String[0]},
+                {"/dependency-management", new String[] {".0", ".+"}, true, new String[0]},
+                {"/gradle-consistent-versions", new String[] {"ignored"}, false, new String[] {"--write-locks"}},
+        };
         return Arrays.asList(data);
     }
 
@@ -33,15 +51,25 @@ public DetectScalaLibraryTest() {
     @Test
     public void test() {
         setProjectName("detect-scala-library" + projectDir);
-        testWithParameter(SCALA_LIBRARY_PARAMETER + SCALA_VERSION + ".0");
-        testWithParameter(SCALA_LIBRARY_PARAMETER + SCALA_VERSION + ".+");
+        for (String subVersion : subVersions) {
+            testWithParameter(SCALA_LIBRARY_PARAMETER + SCALA_VERSION + subVersion, detect);
+        }
     }
 
-    private void testWithParameter(String parameter) {
-        AssertableBuildResult result = dryRun("clean", parameter, "--info");
+    private void testWithParameter(String parameter, Boolean detect) {
+
+        String[] basicParameters = {"clean", parameter, "--info"};
+        String[] parameters = Stream.concat(Arrays.stream(basicParameters), Arrays.stream(additionalParameters))
+                .toArray(String[]::new);
+        AssertableBuildResult result = dryRun(parameters);
+
         String output = result.getResult().getOutput();
-        Assert.assertTrue(output.contains(EXPECTED_OUTPUT_A));
-        Assert.assertTrue(output.contains(EXPECTED_OUTPUT_B));
+        if (detect) {
+            Assert.assertTrue(output.contains(EXPECTED_OUTPUT_DETECTED_VERSION));
+        } else {
+            Assert.assertTrue(output.contains(EXPECTED_OUTPUT_CONFIGURED_VERSION));
+        }
+        Assert.assertTrue(output.contains(EXPECTED_OUTPUT_USING));
     }
 
 }

src/functionalTest/resources/projects/detect-scala-library/gradle-consistent-versions/build.gradle

@@ -0,0 +1,19 @@
+plugins {
+    id "com.palantir.consistent-versions" version "1.16.0"
+    id 'org.scoverage'
+}
+
+repositories {
+    jcenter()
+}
+
+description = 'defines scala library using the "implementation" configuration and the gradle-consistent-versions plugin'
+
+dependencies {
+    implementation group: 'org.scala-lang', name: 'scala-library'
+}
+
+scoverage {
+    // 'detectedScalaLibraryVersion' is set by the test `DetectScalaLibraryTest.java`
+    scoverageScalaVersion = detectedScalaLibraryVersion
+}

src/functionalTest/resources/projects/detect-scala-library/gradle-consistent-versions/versions.lock

@@ -0,0 +1,2 @@
+# Run ./gradlew --write-locks to regenerate this file
+org.scala-lang:scala-library:2.12.0 (1 constraints: 3705353b)

src/functionalTest/resources/projects/detect-scala-library/gradle-consistent-versions/versions.props

@@ -0,0 +1 @@
+org.scala-lang:scala-library = 2.12.0

src/main/groovy/org/scoverage/ScoverageExtension.groovy

@@ -60,7 +60,6 @@ class ScoverageExtension {
         scoverageVersion.set('1.4.1')
 
         scoverageScalaVersion = project.objects.property(String)
-        scoverageScalaVersion.set('2.12')
 
         sources = project.objects.property(File)
         sources.set(project.projectDir)

src/main/groovy/org/scoverage/ScoveragePlugin.groovy

@@ -1,7 +1,6 @@
 package org.scoverage
 
 import org.apache.commons.io.FileUtils
-import org.gradle.api.GradleException
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.Task
@@ -25,10 +24,10 @@ class ScoveragePlugin implements Plugin<PluginAware> {
     static final String CHECK_NAME = 'checkScoverage'
     static final String COMPILE_NAME = 'compileScoverageScala'
     static final String AGGREGATE_NAME = 'aggregateScoverage'
+    static final String DEFAULT_SCALA_VERSION = '2.12'
 
     static final String DEFAULT_REPORT_DIR = 'reports' + File.separatorChar + 'scoverage'
 
-    private volatile File pluginFile = null
     private final ConcurrentHashMap<Task, Set<? extends Task>> taskDependencies = new ConcurrentHashMap<>();
 
     @Override
@@ -173,13 +172,7 @@ class ScoveragePlugin implements Plugin<PluginAware> {
             }
 
             compileTask.configure {
-                if (pluginFile == null) {
-                    pluginFile = project.configurations[CONFIGURATION_NAME].find {
-                        it.name.startsWith("scalac-scoverage-plugin")
-                    }
-                }
-
-                List<String> parameters = ['-Xplugin:' + pluginFile.absolutePath]
+                List<String> parameters = []
                 List<String> existingParameters = scalaCompileOptions.additionalParameters
                 if (existingParameters) {
                     parameters.addAll(existingParameters)
@@ -199,6 +192,18 @@ class ScoveragePlugin implements Plugin<PluginAware> {
                 scalaCompileOptions.additionalParameters = parameters
                 // the compile task creates a store of measured statements
                 outputs.file(new File(extension.dataDir.get(), 'scoverage.coverage.xml'))
+
+                dependsOn project.configurations[CONFIGURATION_NAME]
+                doFirst {
+                    /*
+                        It is crucial that this would run in `doFirst`, as this resolves the (dependencies of the)
+                        configuration, which we do not want to do at configuration time (but only at execution time).
+                     */
+                    def pluginFile = project.configurations[CONFIGURATION_NAME].find {
+                        it.name.startsWith("scalac-scoverage-plugin")
+                    }
+                    scalaCompileOptions.additionalParameters.add('-Xplugin:' + pluginFile.absolutePath)
+                }
             }
 
             project.gradle.taskGraph.whenReady { graph ->
@@ -343,19 +348,26 @@ class ScoveragePlugin implements Plugin<PluginAware> {
 
     private String resolveScalaVersion(Project project) {
 
-        def resolvedDependencies = project.configurations.compileClasspath.resolvedConfiguration.firstLevelModuleDependencies
-
-        def scalaLibrary = resolvedDependencies.find {
-            it.moduleGroup == "org.scala-lang" && it.moduleName == "scala-library"
-        }
-
-        if (scalaLibrary == null) {
-            project.logger.info("No scala library detected. Using property 'scoverageScalaVersion'")
-            return project.extensions.scoverage.scoverageScalaVersion.get()
+        def scalaVersionProperty = project.extensions.scoverage.scoverageScalaVersion
+        if (scalaVersionProperty.isPresent()) {
+            def configuredScalaVersion = scalaVersionProperty.get()
+            project.logger.info("Using configured Scala version: $configuredScalaVersion")
+            return configuredScalaVersion
         } else {
-            project.logger.info("Detected scala library in compilation classpath")
-            def fullScalaVersion = scalaLibrary.moduleVersion
-            return fullScalaVersion.substring(0, fullScalaVersion.lastIndexOf("."))
+            project.logger.info("No Scala version configured. Detecting scala library...")
+            def components = project.configurations.compileClasspath.incoming.resolutionResult.getAllComponents()
+            def scalaLibrary = components.find {
+                it.moduleVersion.group == "org.scala-lang" && it.moduleVersion.name == "scala-library"
+            }
+            if (scalaLibrary != null) {
+                def fullScalaVersion = scalaLibrary.moduleVersion.version
+                def scalaVersion = fullScalaVersion.substring(0, fullScalaVersion.lastIndexOf("."))
+                project.logger.info("Detected scala library in compilation classpath. Scala version: $scalaVersion")
+                return scalaVersion
+            } else {
+                project.logger.info("No scala library detected. Using default Scala version: $DEFAULT_SCALA_VERSION")
+                return DEFAULT_SCALA_VERSION
+            }
         }
     }