adding a test to prove that we can support prettier-plugins now

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/PrettierIntegrationTest.java

@@ -17,6 +17,8 @@
 
 import java.io.IOException;
 
+import org.assertj.core.api.Assertions;
+import org.gradle.testkit.runner.BuildResult;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 
@@ -41,7 +43,8 @@ public void useInlineConfig() throws IOException {
 				"    }",
 				"}");
 		setFile("test.ts").toResource("npm/prettier/config/typescript.dirty");
-		gradleRunner().withArguments("--stacktrace", "spotlessApply").build();
+		final BuildResult spotlessApply = gradleRunner().withArguments("--stacktrace", "spotlessApply").build();
+		Assertions.assertThat(spotlessApply.getOutput()).contains("BUILD SUCCESSFUL");
 		assertFile("test.ts").sameAsResource("npm/prettier/config/typescript.configfile.clean");
 	}
 
@@ -60,8 +63,33 @@ public void useFileConfig() throws IOException {
 				"    }",
 				"}");
 		setFile("test.ts").toResource("npm/prettier/config/typescript.dirty");
-		gradleRunner().withArguments("--stacktrace", "spotlessApply").build();
+		final BuildResult spotlessApply = gradleRunner().withArguments("--stacktrace", "spotlessApply").build();
+		Assertions.assertThat(spotlessApply.getOutput()).contains("BUILD SUCCESSFUL");
 		assertFile("test.ts").sameAsResource("npm/prettier/config/typescript.configfile.clean");
 	}
 
+	@Test
+	public void useJavaCommunityPlugin() throws IOException {
+		setFile("build.gradle").toLines(
+				"buildscript { repositories { mavenCentral() } }",
+				"plugins {",
+				"    id 'com.diffplug.gradle.spotless'",
+				"}",
+				"def prettierConfig = [:]",
+				"prettierConfig['tabWidth'] = 4",
+				"prettierConfig['parser'] = 'java'",
+				"def prettierPackages = [:]",
+				"prettierPackages['prettier'] = '2.0.5'",
+				"prettierPackages['prettier-plugin-java'] = '0.8.0'",
+				"spotless {",
+				"    format 'java', {",
+				"        target 'JavaTest.java'",
+				"        prettier(prettierPackages).config(prettierConfig)",
+				"    }",
+				"}");
+		setFile("JavaTest.java").toResource("npm/prettier/plugins/java-test.dirty");
+		final BuildResult spotlessApply = gradleRunner().withArguments("--stacktrace", "spotlessApply").build();
+		Assertions.assertThat(spotlessApply.getOutput()).contains("BUILD SUCCESSFUL");
+		assertFile("JavaTest.java").sameAsResource("npm/prettier/plugins/java-test.clean");
+	}
 }

testlib/src/main/resources/npm/prettier/plugins/java-test.clean

@@ -0,0 +1,37 @@
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Consumer;
+
+public class JavaTest {
+    private static final String NAME = "JavaTest";
+
+    private List<String> strings = new ArrayList<>();
+
+    public JavaTest(String... strings) {
+        this.strings.addAll(Arrays.asList(strings));
+    }
+
+    /**
+     * Join using char.
+     * @param joiner the char to use for joining.
+     * @return the joined string.
+     */
+    public String join(char joiner) {
+        return String.join(joiner, strings);
+    }
+
+    public void operateOn(Consumer<List<String>> consumer) {
+        // test comment
+        consumer.accept(strings);
+    }
+
+    public static void main(String[] args) {
+        JavaTest javaTest = new JavaTest("1", "2", "3");
+        System.out.println("joined: " + javaTest.join(','));
+        StringBuilder builder = new StringBuilder();
+        javaTest.operateOn(
+            strings -> builder.append(String.join("---", strings))
+        );
+    }
+}

testlib/src/main/resources/npm/prettier/plugins/java-test.dirty

@@ -0,0 +1,30 @@
+import java.util.ArrayList;
+
+
+import java.util.Arrays;import java.util.List;
+import java.util.function.Consumer;
+
+public class JavaTest { private static final String NAME = "JavaTest";
+
+    private List<String> strings = new ArrayList<>();
+
+    public JavaTest(     String            ... strings) {
+        this.strings .addAll(Arrays.asList(strings));;
+    }
+
+/**
+* Join using char.
+* @param joiner the char to use for joining.
+* @return the joined string.
+*/
+    public String
+        join(char joiner ) {
+        return String.join(joiner, strings);
+    }
+
+    public void operateOn(        Consumer<List<String>>  consumer) {
+// test comment
+        consumer.accept(          strings);
+    }
+
+    public static void main(String[] args) {JavaTest javaTest = new JavaTest("1", "2", "3");System.out.println("joined: " + javaTest.join(','          ));StringBuilder builder = new StringBuilder();javaTest.operateOn((strings) -> builder.append(String.join("---", strings)));}}