Assure Maven 3.1.0 compatibility and fix dependencies

gradle.properties

@@ -30,6 +30,6 @@ VER_MOCKITO=3.3.3
 
 # Used for Maven Plugin
 VER_MAVEN_API=3.0
-VER_ECLIPSE_AETHER=1.1.0
+VER_ECLIPSE_AETHER=0.9.0.M2
 VER_MUSTACHE=0.9.6
-VER_PLEXUS_RESOURCES=1.0.1
+VER_PLEXUS_RESOURCES=1.2.0

plugin-maven/build.gradle

@@ -69,22 +69,14 @@ dependencies {
 		implementation "com.diffplug.spotless:spotless-lib-extra:${libVersion}"
 	}
 
-	implementation "org.codehaus.plexus:plexus-resources:${VER_PLEXUS_RESOURCES}"
-	constraints {
-		implementation("org.codehaus.plexus:plexus-utils:3.4.1") {
-			because("version pulled by plexus-resources has a functional-bug affecting " +
-					"directory scanning times")
-		}
-	}
-
 	compileOnly "org.apache.maven:maven-plugin-api:${VER_MAVEN_API}"
 	compileOnly "org.apache.maven.plugin-tools:maven-plugin-annotations:${VER_MAVEN_API}"
 	compileOnly "org.apache.maven:maven-core:${VER_MAVEN_API}"
 	compileOnly "org.eclipse.aether:aether-api:${VER_ECLIPSE_AETHER}"
-	compileOnly "org.eclipse.aether:aether-util:${VER_ECLIPSE_AETHER}"
 
 	implementation "com.diffplug.durian:durian-core:${VER_DURIAN}"
 	implementation "com.diffplug.durian:durian-collect:${VER_DURIAN}"
+	implementation("org.codehaus.plexus:plexus-resources:${VER_PLEXUS_RESOURCES}")
 	implementation "org.eclipse.jgit:org.eclipse.jgit:${VER_JGIT}"
 
 	testImplementation project(":testlib")

plugin-maven/src/test/java/com/diffplug/spotless/maven/MavenIntegrationHarness.java

@@ -96,7 +96,7 @@ private File copy(String path) throws IOException {
 	}
 
 	protected void writePomWithFormatSteps(String... steps) throws IOException {
-		writePom(formats(groupWithSteps("format", including("<include>src/**/java/**/*.java</include>"), steps)));
+		writePom(formats(groupWithSteps("format", including("src/**/java/**/*.java"), steps)));
 	}
 
 	protected void writePomWithAntlr4Steps(String... steps) throws IOException {
@@ -241,7 +241,7 @@ private static String[] groupWithSteps(String group, String... steps) {
 	}
 
 	private static String[] including(String... includes) {
-		return groupWithSteps("includes", includes);
+		return groupWithSteps("includes", groupWithSteps("include", includes));
 	}
 
 	private static String[] formats(String... formats) {

plugin-maven/src/test/java/com/diffplug/spotless/maven/java/EclipseFormatStepTest.java

@@ -26,7 +26,6 @@ void testEclipse() throws Exception {
 		writePomWithJavaSteps(
 				"<eclipse>",
 				"  <file>${basedir}/formatter.xml</file>",
-				"  <version>4.7.1</version>",
 				"</eclipse>");
 		setFile("formatter.xml").toResource("java/eclipse/formatter.xml");
 

plugin-maven/src/test/resources/.mvn/wrapper/maven-wrapper.properties

@@ -1 +1,5 @@
-distributionUrl=https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.5.2/apache-maven-3.5.2-bin.zip
+# Maven version 3.2.5 is the earliest version which can cope with the 
+# maven-plugin-plugin 3.5 (see pom-build.xml.mustache).
+# The Maven version used for build and test is not relevant for compatibility.
+# Instead the versions of the provided dependencies (see pom-build.xml.mustache) must match. 
+distributionUrl=https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.2.5/apache-maven-3.2.5-bin.zip