Add step to forbid module imports

.github/workflows/claude.yml

@@ -21,6 +21,7 @@ jobs:
       contents: read
       pull-requests: read
       issues: read
+      members: read
       id-token: write
     steps:
       - name: Check team membership

CHANGES.md

@@ -12,6 +12,8 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ## [Unreleased]
 ### Fixed
 - palantirJavaFormat is no longer arbitrarily set to outdated versions on Java 17, latest available version is always used ([#2686](https://github.com/diffplug/spotless/pull/2686) fixes [#2685](https://github.com/diffplug/spotless/issues/2685))
+### Added
+- Add a `forbidModuleImports` API for java ([#2679](https://github.com/diffplug/spotless/issues/2679))
 
 ## [4.0.0] - 2025-09-24
 ### Changes

README.md

@@ -86,6 +86,7 @@ lib('java.ImportOrderStep')                      +'{{yes}}       | {{yes}}
 lib('java.PalantirJavaFormatStep')               +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 lib('java.RemoveUnusedImportsStep')              +'{{yes}}       | {{yes}}      | {{yes}}      | {{no}}  |',
 lib('java.ForbidWildcardImportsStep')            +'{{yes}}       | {{yes}}      | {{yes}}      | {{no}}  |',
+lib('java.ForbidModuleImportsStep')              +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 extra('java.EclipseJdtFormatterStep')            +'{{yes}}       | {{yes}}      | {{yes}}      | {{no}}  |',
 lib('java.FormatAnnotationsStep')                +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 lib('java.CleanthatJavaStep')                    +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
@@ -142,6 +143,7 @@ lib('yaml.JacksonYamlStep')                      +'{{yes}}       | {{yes}}
 | [`java.PalantirJavaFormatStep`](lib/src/main/java/com/diffplug/spotless/java/PalantirJavaFormatStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |
 | [`java.RemoveUnusedImportsStep`](lib/src/main/java/com/diffplug/spotless/java/RemoveUnusedImportsStep.java) | :+1:       | :+1:      | :+1:      | :white_large_square:  |
 | [`java.ForbidWildcardImportsStep`](lib/src/main/java/com/diffplug/spotless/java/ForbidWildcardImportsStep.java) | :+1:       | :+1:      | :+1:      | :white_large_square:  |
+| [`java.ForbidModuleImportsStep`](lib/src/main/java/com/diffplug/spotless/java/ForbidModuleImportsStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |
 | [`java.EclipseJdtFormatterStep`](lib-extra/src/main/java/com/diffplug/spotless/extra/java/EclipseJdtFormatterStep.java) | :+1:       | :+1:      | :+1:      | :white_large_square:  |
 | [`java.FormatAnnotationsStep`](lib/src/main/java/com/diffplug/spotless/java/FormatAnnotationsStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |
 | [`java.CleanthatJavaStep`](lib/src/main/java/com/diffplug/spotless/java/CleanthatJavaStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |

lib/src/main/java/com/diffplug/spotless/java/ForbidModuleImportsStep.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2025 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.spotless.java;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.generic.ReplaceRegexStep;
+
+/** Forbids any module import statements. */
+public final class ForbidModuleImportsStep {
+
+	/**
+	 * Matches lines like 'import module java.base;' or 'import module java.sql;'.
+	 */
+	private static final String REGEX = "(?m)^import module[^;\\n]*;\\R?";
+	private static final String NAME = "forbidModuleImports";
+	private static final String ERROR = "Do not use module imports - replace with specific class imports as 'spotlessApply' cannot auto-fix this";
+
+	private ForbidModuleImportsStep() {}
+
+	public static FormatterStep create() {
+		return ReplaceRegexStep.lint(NAME, REGEX, ERROR);
+	}
+}

plugin-gradle/CHANGES.md

@@ -5,6 +5,8 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ## [Unreleased]
 ### Fixed
 - palantirJavaFormat is no longer arbitrarily set to outdated versions on Java 17, latest available version is always used ([#2686](https://github.com/diffplug/spotless/pull/2686) fixes [#2685](https://github.com/diffplug/spotless/issues/2685))
+### Added
+- `forbidModuleImports()` API for java ([#2679](https://github.com/diffplug/spotless/issues/2679))
 
 ## [8.0.0] - 2025-09-24
 ### Changed

plugin-gradle/README.md

@@ -207,6 +207,7 @@ spotless {
 
     removeUnusedImports()
     forbidWildcardImports()
+    forbidModuleImports()
 
     // Cleanthat will refactor your code, but it may break your style: apply it before your formatter
     cleanthat()          // has its own section below
@@ -257,6 +258,16 @@ spotless {
 }
 ```
 
+### forbidModuleImports
+
+```
+spotless {
+  java {
+    forbidModuleImports()
+  }
+}
+```
+
 ### google-java-format
 
 [homepage](https://github.com/google/google-java-format). [changelog](https://github.com/google/google-java-format/releases).

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

@@ -36,6 +36,7 @@
 import com.diffplug.spotless.extra.java.EclipseJdtFormatterStep;
 import com.diffplug.spotless.generic.LicenseHeaderStep;
 import com.diffplug.spotless.java.CleanthatJavaStep;
+import com.diffplug.spotless.java.ForbidModuleImportsStep;
 import com.diffplug.spotless.java.ForbidWildcardImportsStep;
 import com.diffplug.spotless.java.FormatAnnotationsStep;
 import com.diffplug.spotless.java.GoogleJavaFormatStep;
@@ -162,6 +163,10 @@ public void forbidWildcardImports() {
 		addStep(ForbidWildcardImportsStep.create());
 	}
 
+	public void forbidModuleImports() {
+		addStep(ForbidModuleImportsStep.create());
+	}
+
 	/** Uses the <a href="https://github.com/google/google-java-format">google-java-format</a> jar to format source code. */
 	public GoogleJavaFormatConfig googleJavaFormat() {
 		return googleJavaFormat(GoogleJavaFormatStep.defaultVersion());

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

@@ -82,7 +82,7 @@ void removeUnusedImportsWithCleanthat() throws IOException {
 	}
 
 	@Test
-	void removeWildCardImports() throws IOException {
+	void forbidWildcardImports() throws IOException {
 		setFile("build.gradle").toLines(
 				"plugins {",
 				"    id 'com.diffplug.spotless'",
@@ -92,13 +92,33 @@ void removeWildCardImports() throws IOException {
 				"spotless {",
 				"    java {",
 				"        target file('test.java')",
-				"        removeWildcardImports()",
+				"        forbidWildcardImports()",
 				"    }",
 				"}");
 
-		setFile("test.java").toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile("test.java").toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 		gradleRunner().withArguments("spotlessApply").buildAndFail();
-		assertFile("test.java").sameAsResource("java/removewildcardimports/JavaCodeWildcardsFormatted.test");
+		assertFile("test.java").sameAsResource("java/forbidwildcardimports/JavaCodeWildcardsFormatted.test");
+	}
+
+	@Test
+	void forbidModuleImports() throws IOException {
+		setFile("build.gradle").toLines(
+				"plugins {",
+				"    id 'com.diffplug.spotless'",
+				"}",
+				"repositories { mavenCentral() }",
+				"",
+				"spotless {",
+				"    java {",
+				"        target file('test.java')",
+				"        forbidModuleImports()",
+				"    }",
+				"}");
+
+		setFile("test.java").toResource("java/forbidmoduleimports/JavaCodeModuleImportsUnformatted.test");
+		gradleRunner().withArguments("spotlessApply").buildAndFail();
+		assertFile("test.java").sameAsResource("java/forbidmoduleimports/JavaCodeModuleImportsFormatted.test");
 	}
 
 	/**

plugin-maven/CHANGES.md

@@ -5,6 +5,8 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ## [Unreleased]
 ### Fixed
 - palantirJavaFormat is no longer arbitrarily set to outdated versions on Java 17, latest available version is always used ([#2686](https://github.com/diffplug/spotless/pull/2686) fixes [#2685](https://github.com/diffplug/spotless/issues/2685))
+### Added
+- `<forbidModuleImports>` API for java ([#2679](https://github.com/diffplug/spotless/issues/2679))
 
 ## [3.0.0] - 2025-09-24
 ### Changes

plugin-maven/README.md

@@ -231,6 +231,7 @@ any other maven phase (i.e. compile) then it can be configured as below;
 
     <removeUnusedImports /> <!-- self-explanatory -->
     <forbidWildcardImports /> <!-- yell if any import ends with '*' -->
+    <forbidModuleImports /> <!-- yell if any module imports are found (Java 25+) -->
 
     <formatAnnotations />  <!-- fixes formatting of type annotations, see below -->
 
@@ -255,6 +256,12 @@ any other maven phase (i.e. compile) then it can be configured as below;
 <forbidWildcardImports/>
 ```
 
+### forbidModuleImports
+
+```xml
+<forbidModuleImports/>
+```
+
 ### google-java-format
 
 [homepage](https://github.com/google/google-java-format). [changelog](https://github.com/google/google-java-format/releases). [code](https://github.com/diffplug/spotless/blob/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/java/GoogleJavaFormat.java).

plugin-maven/src/main/java/com/diffplug/spotless/maven/java/ForbidModuleImports.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2025 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.spotless.maven.java;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.java.ForbidModuleImportsStep;
+import com.diffplug.spotless.maven.FormatterStepConfig;
+import com.diffplug.spotless.maven.FormatterStepFactory;
+
+public class ForbidModuleImports implements FormatterStepFactory {
+	@Override
+	public FormatterStep newFormatterStep(FormatterStepConfig config) {
+		return ForbidModuleImportsStep.create();
+	}
+}

plugin-maven/src/main/java/com/diffplug/spotless/maven/java/Java.java

@@ -80,6 +80,10 @@ public void addForbidWildcardImports(ForbidWildcardImports forbidWildcardImports
 		addStepFactory(forbidWildcardImports);
 	}
 
+	public void addForbidModuleImports(ForbidModuleImports forbidModuleImports) {
+		addStepFactory(forbidModuleImports);
+	}
+
 	public void addFormatAnnotations(FormatAnnotations formatAnnotations) {
 		addStepFactory(formatAnnotations);
 	}

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

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2025 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.spotless.maven.java;
+
+import org.junit.jupiter.api.Test;
+
+import com.diffplug.spotless.maven.MavenIntegrationHarness;
+
+class ForbidModuleImportsStepTest extends MavenIntegrationHarness {
+
+	@Test
+	void testForbidModuleImports() throws Exception {
+		writePomWithJavaSteps("<forbidModuleImports/>");
+
+		String path = "src/main/java/test.java";
+		setFile(path).toResource("java/forbidmoduleimports/JavaCodeModuleImportsUnformatted.test");
+		var selfie = expectSelfieErrorMsg(mavenRunner().withArguments("spotless:apply").runHasError());
+		assertFile(path).sameAsResource("java/forbidmoduleimports/JavaCodeModuleImportsUnformatted.test");
+		selfie.toBe("""
+				Failed to execute goal com.diffplug.spotless:spotless-maven-plugin:VERSION:apply (default-cli) on project spotless-maven-plugin-tests: There were 2 lint error(s), they must be fixed or suppressed.
+				src/main/java/test.java:L1 forbidModuleImports(import module java.base;) Do not use module imports - replace with specific class imports as 'spotlessApply' cannot auto-fix this
+				src/main/java/test.java:L2 forbidModuleImports(import module java.sql;) Do not use module imports - replace with specific class imports as 'spotlessApply' cannot auto-fix this
+				Resolve these lints or suppress with `<lintSuppressions>`
+				""");
+	}
+}

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

@@ -26,9 +26,9 @@ void testForbidWildcardImports() throws Exception {
 		writePomWithJavaSteps("<forbidWildcardImports/>");
 
 		String path = "src/main/java/test.java";
-		setFile(path).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(path).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 		var selfie = expectSelfieErrorMsg(mavenRunner().withArguments("spotless:apply").runHasError());
-		assertFile(path).sameAsResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		assertFile(path).sameAsResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 		selfie.toBe("""
 				Failed to execute goal com.diffplug.spotless:spotless-maven-plugin:VERSION:apply (default-cli) on project spotless-maven-plugin-tests: There were 5 lint error(s), they must be fixed or suppressed.
 				src/main/java/test.java:L1 forbidWildcardImports(import java.util.*;) Do not use wildcard imports (e.g. java.util.*) - replace with specific class imports (e.g. java.util.List) as 'spotlessApply' cannot auto-fix this

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

@@ -30,7 +30,7 @@ void testNoSuppressionFailsOnWildcardImports() throws Exception {
 		writePomWithJavaSteps("<forbidWildcardImports/>");
 
 		String path = "src/main/java/TestFile.java";
-		setFile(path).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(path).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 
 		expectSelfieErrorMsg(mavenRunner().withArguments("spotless:check").runHasError()).toBe("""
 				Failed to execute goal com.diffplug.spotless:spotless-maven-plugin:VERSION:check (default-cli) on project spotless-maven-plugin-tests: Unable to format file ${PROJECT_DIR}/src/main/java/TestFile.java
@@ -58,8 +58,8 @@ void testSuppressByFilePath() throws Exception {
 		String suppressedFile = "src/main/java/TestFile1.java";
 		String unsuppressedFile = "src/main/java/TestFile2.java";
 
-		setFile(suppressedFile).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
-		setFile(unsuppressedFile).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(suppressedFile).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(unsuppressedFile).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 
 		var result = mavenRunner().withArguments("spotless:check").runHasError();
 		assertThat(result.stdOutUtf8()).contains("TestFile2.java");
@@ -79,7 +79,7 @@ void testSuppressByStep() throws Exception {
 				"</lintSuppressions>");
 
 		String path = "src/main/java/TestFile.java";
-		setFile(path).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(path).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 
 		// Should succeed because we suppressed the entire step
 		mavenRunner().withArguments("spotless:check").runNoError();
@@ -99,7 +99,7 @@ void testSuppressByShortCode() throws Exception {
 				"</lintSuppressions>");
 
 		String path = "src/main/java/TestFile.java";
-		setFile(path).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(path).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 
 		// Should succeed because we suppressed all error codes
 		mavenRunner().withArguments("spotless:check").runNoError();
@@ -126,9 +126,9 @@ void testMultipleSuppressionsWork() throws Exception {
 		String file2 = "src/main/java/TestFile2.java";
 		String file3 = "src/main/java/TestFile3.java";
 
-		setFile(file1).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
-		setFile(file2).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
-		setFile(file3).toResource("java/removewildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(file1).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(file2).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
+		setFile(file3).toResource("java/forbidwildcardimports/JavaCodeWildcardsUnformatted.test");
 
 		var result = mavenRunner().withArguments("spotless:check").runHasError();
 		assertThat(result.stdOutUtf8()).contains("TestFile3.java");

testlib/src/main/resources/java/forbidmoduleimports/JavaCodeModuleImportsFormatted.test

@@ -0,0 +1,4 @@
+import module java.base;
+import module java.sql;
+
+public class Test {}

testlib/src/main/resources/java/forbidmoduleimports/JavaCodeModuleImportsUnformatted.test

@@ -0,0 +1,4 @@
+import module java.base;
+import module java.sql;
+
+public class Test {}