Introduce go extension for plugin-gradle

Author: petertrr

lib/src/main/java/com/diffplug/spotless/go/GofmtFormatStep.java

@@ -43,7 +43,7 @@ public static String name() {
 	}
 
 	public static String defaultVersion() {
-		return "1.20.0";
+		return "go1.20.0";
 	}
 
 	private final String version;

plugin-gradle/src/main/java/com/diffplug/gradle/spotless/FormatExtension.java

@@ -957,33 +957,6 @@ public EclipseWtpConfig eclipseWtp(EclipseWtpFormatterStep type, String version)
 		return new EclipseWtpConfig(type, version);
 	}
 
-	public class GofmtConfig {
-		GofmtFormatStep stepCfg;
-
-		public GofmtConfig(String version) {
-			stepCfg = (GofmtFormatStep) GofmtFormatStep.withVersion(version).create();
-			addStep(createStep());
-		}
-
-		public GofmtConfig withGoExecutable(String pathToGo) {
-			stepCfg = stepCfg.withGoExecutable(pathToGo);
-			replaceStep(createStep());
-			return this;
-		}
-
-		private FormatterStep createStep() {
-			return stepCfg.create();
-		}
-	}
-
-	public GofmtConfig gofmt() {
-		return new GofmtConfig(GofmtFormatStep.defaultVersion());
-	}
-
-	public GofmtConfig gofmt(String version) {
-		return new GofmtConfig(version);
-	}
-
 	/**
 	 * <pre>
 	 * spotless {

plugin-gradle/src/main/java/com/diffplug/gradle/spotless/GoExtension.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2024 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.gradle.spotless;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.go.GofmtFormatStep;
+
+import javax.inject.Inject;
+
+public class GoExtension extends FormatExtension {
+    public static final String NAME = "go";
+
+    @Inject
+    public GoExtension(SpotlessExtension spotless) {
+        super(spotless);
+    }
+
+    public GofmtConfig gofmt() {
+        return new GofmtConfig(GofmtFormatStep.defaultVersion());
+    }
+
+    public GofmtConfig gofmt(String version) {
+        return new GofmtConfig(version);
+    }
+
+    public class GofmtConfig {
+        GofmtFormatStep stepCfg;
+
+        public GofmtConfig(String version) {
+            stepCfg = GofmtFormatStep.withVersion(version);
+            addStep(createStep());
+        }
+
+        public GofmtConfig withGoExecutable(String pathToGo) {
+            stepCfg = stepCfg.withGoExecutable(pathToGo);
+            replaceStep(createStep());
+            return this;
+        }
+
+        private FormatterStep createStep() {
+            return stepCfg.create();
+        }
+    }
+}

plugin-gradle/src/main/java/com/diffplug/gradle/spotless/SpotlessExtension.java

@@ -223,6 +223,11 @@ public void gherkin(Action<GherkinExtension> closure) {
 		format(GherkinExtension.NAME, GherkinExtension.class, closure);
 	}
 
+	public void go(Action<GoExtension> closure) {
+		requireNonNull(closure);
+		format(GoExtension.NAME, GoExtension.class, closure);
+	}
+
 	/** Configures a custom extension. */
 	public void format(String name, Action<FormatExtension> closure) {
 		requireNonNull(name, "name");

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

@@ -30,9 +30,9 @@ void gofmt() throws IOException {
 				"  id 'com.diffplug.spotless'",
 				"}",
 				"spotless {",
-				"  format 'go' {",
+				"  go {",
 				"    target 'src/**/*.go'",
-				"    gofmt()",
+				"    gofmt(\"go1.21.5\")",
 				"  }",
 				"}");
 		setFile("src/test.go").toResource("go/gofmt/go.dirty");