Add JUnit 5 checkstyle rule

Fixes gh-106

spring-javaformat/spring-javaformat-checkstyle/src/main/java/io/spring/javaformat/checkstyle/check/SpringJUnit5Check.java

@@ -0,0 +1,149 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 io.spring.javaformat.checkstyle.check;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.FullIdent;
+import com.puppycrawl.tools.checkstyle.api.TokenTypes;
+import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
+
+/**
+ * Checks that JUnit 5 conventions are followed and that JUnit 4 is not accidentally used.
+ *
+ * @author Phillip Webb
+ */
+public class SpringJUnit5Check extends AbstractSpringCheck {
+
+	private static final String JUNIT4_TEST_ANNOTATION = "org.junit.Test";
+
+	private static final String JUNIT5_TEST_ANNOTATION = "org.junit.jupiter.api.Test";
+
+	private static final List<String> TEST_ANNOTATIONS = Collections
+			.unmodifiableList(Arrays.asList("Test", JUNIT4_TEST_ANNOTATION, JUNIT5_TEST_ANNOTATION));
+
+	private static final List<String> BANNED_IMPORTS;
+	static {
+		List<String> bannedImports = new ArrayList<>();
+		bannedImports.add(JUNIT4_TEST_ANNOTATION);
+		bannedImports.add("org.junit.After");
+		bannedImports.add("org.junit.AfterClass");
+		bannedImports.add("org.junit.Before");
+		bannedImports.add("org.junit.BeforeClass");
+		bannedImports.add("org.junit.Rule");
+		bannedImports.add("org.junit.ClassRule");
+		BANNED_IMPORTS = Collections.unmodifiableList(bannedImports);
+	}
+
+	private List<String> unlessImports = new ArrayList<>();
+
+	private final List<DetailAST> testMethods = new ArrayList<>();
+
+	private final Map<String, FullIdent> imports = new LinkedHashMap<>();
+
+	@Override
+	public int[] getAcceptableTokens() {
+		return new int[] { TokenTypes.METHOD_DEF, TokenTypes.IMPORT };
+	}
+
+	@Override
+	public void beginTree(DetailAST rootAST) {
+		this.testMethods.clear();
+	}
+
+	@Override
+	public void visitToken(DetailAST ast) {
+		switch (ast.getType()) {
+		case TokenTypes.METHOD_DEF:
+			visitMethodDef(ast);
+		case TokenTypes.IMPORT:
+			visitImport(ast);
+			break;
+		}
+	}
+
+	private void visitMethodDef(DetailAST ast) {
+		if (AnnotationUtil.containsAnnotation(ast, TEST_ANNOTATIONS)) {
+			this.testMethods.add(ast);
+		}
+	}
+
+	private void visitImport(DetailAST ast) {
+		FullIdent ident = FullIdent.createFullIdentBelow(ast);
+		this.imports.put(ident.getText(), ident);
+	}
+
+	@Override
+	public void finishTree(DetailAST rootAST) {
+		if (shouldCheck()) {
+			check();
+		}
+	}
+
+	private boolean shouldCheck() {
+		if (this.testMethods.isEmpty()) {
+			return false;
+		}
+		for (String unlessImport : this.unlessImports) {
+			if (this.imports.containsKey(unlessImport)) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	private void check() {
+		for (String bannedImport : BANNED_IMPORTS) {
+			FullIdent ident = this.imports.get(bannedImport);
+			if (ident != null) {
+				log(ident.getLineNo(), ident.getColumnNo(), "junit5.bannedImport", bannedImport);
+			}
+		}
+		for (DetailAST testMethod : this.testMethods) {
+			if (AnnotationUtil.containsAnnotation(testMethod, JUNIT4_TEST_ANNOTATION)) {
+				log(testMethod, "junit5.bannedTestAnnotation");
+			}
+		}
+		for (DetailAST testMethod : this.testMethods) {
+			DetailAST modifiers = testMethod.findFirstToken(TokenTypes.MODIFIERS);
+			if (modifiers.findFirstToken(TokenTypes.LITERAL_PUBLIC) != null) {
+				log(testMethod, "junit5.publicMethod");
+			}
+			if (modifiers.findFirstToken(TokenTypes.LITERAL_PRIVATE) != null) {
+				log(testMethod, "junit5.privateMethod");
+			}
+		}
+	}
+
+	private void log(DetailAST method, String key) {
+		String name = method.findFirstToken(TokenTypes.IDENT).getText();
+		log(method.getLineNo(), method.getColumnNo(), key, name);
+	}
+
+	public void setUnlessImports(String unlessImports) {
+		this.unlessImports = Collections.unmodifiableList(
+				Arrays.stream(unlessImports.split(",")).map(String::trim).collect(Collectors.toList()));
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/main/resources/io/spring/javaformat/checkstyle/check/messages.properties

@@ -8,3 +8,7 @@ javadoc.badCase=Javadoc element descriptions should not start with an uppercase
 header.unexpected=Unexpected header.
 nothis.unexpected=Reference to instance variable ''{0}'' should not use \"this.\".
 methodorder.outOfOrder=Method ''{0}'' is out of order, expected {1}.
+junit5.publicMethod="Test method ''{0}'' should not be public."
+junit5.privateMethod="Test method ''{0}'' should not be private."
+junit5.bannedImport="Import ''{0}'' should not be used in a JUnit 5 test."
+junit5.bannedTestAnnotation="JUnit 4 @Test annotation should not be used in a JUnit 5 test."

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/JUnit5BadAnnotation.txt

@@ -0,0 +1 @@
++JUnit 4 @Test annotation should not be used in a JUnit 5 test.

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/JUnit5BadImport.txt

@@ -0,0 +1 @@
++Import 'org.junit.Before' should not be used in a JUnit 5 test.

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/JUnit5BadImportWithOptOut.txt

@@ -0,0 +1 @@
++0 errors

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/JUnit5BadModifier.txt

@@ -0,0 +1,2 @@
++Test method 'doSomethingWorks' should not be public
++Test method 'doSomethingElseWorks' should not be private

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/check/JUnit5Valid.txt

@@ -0,0 +1 @@
++0 errors

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/config/JUnit5BadAnnotation.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+		"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+		"https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="com.puppycrawl.tools.checkstyle.Checker">
+	<module name="com.puppycrawl.tools.checkstyle.TreeWalker">
+		<module name="io.spring.javaformat.checkstyle.check.SpringJUnit5Check">
+		</module>
+ 	</module>
+</module>

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/config/JUnit5BadImport.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+		"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+		"https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="com.puppycrawl.tools.checkstyle.Checker">
+	<module name="com.puppycrawl.tools.checkstyle.TreeWalker">
+		<module name="io.spring.javaformat.checkstyle.check.SpringJUnit5Check">
+		</module>
+ 	</module>
+</module>

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/config/JUnit5BadImportWithOptOut.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+		"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+		"https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="com.puppycrawl.tools.checkstyle.Checker">
+	<module name="com.puppycrawl.tools.checkstyle.TreeWalker">
+		<module name="io.spring.javaformat.checkstyle.check.SpringJUnit5Check">
+			<property name="unlessImports" value="com.example.OptOutRunner"/>
+		</module>
+ 	</module>
+</module>

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/config/JUnit5BadModifier.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+		"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+		"https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="com.puppycrawl.tools.checkstyle.Checker">
+	<module name="com.puppycrawl.tools.checkstyle.TreeWalker">
+		<module name="io.spring.javaformat.checkstyle.check.SpringJUnit5Check">
+		</module>
+ 	</module>
+</module>

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/config/JUnit5Valid.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+		"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+		"https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="com.puppycrawl.tools.checkstyle.Checker">
+	<module name="com.puppycrawl.tools.checkstyle.TreeWalker">
+		<module name="io.spring.javaformat.checkstyle.check.SpringJUnit5Check">
+		</module>
+ 	</module>
+</module>

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/JUnit5BadAnnotation.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+/**
+ * Test with bad full qualified annotation.
+ *
+ * @author Phillip Webb
+ */
+public class JUnit5BadAnnotation {
+
+	@org.junit.Test
+	void doSomethingWorks() {
+		// test here
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/JUnit5BadImport.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+import org.junit.jupiter.api.Test;
+import org.junit.Before;
+
+/**
+ * Test with banned import.
+ *
+ * @author Phillip Webb
+ */
+public class JUnit5BadImport {
+
+	@Before
+	public void bad() {
+	}
+
+	@Test
+	void doSomethingWorks() {
+		// test here
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/JUnit5BadImportWithOptOut.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+import com.example.OptOutRunner;
+import org.junit.RunWith;
+import org.junit.Test;
+
+/**
+ * Test with banned import but also opt-out trigger.
+ *
+ * @author Phillip Webb
+ */
+@RunWith(OptOutRunner.class)
+public class JUnit5BadImportWithOptOut {
+
+	@Test
+	void doSomethingWorks() {
+		// test here
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/JUnit5BadModifier.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test with bad modifiers.
+ *
+ * @author Phillip Webb
+ */
+public class JUnit5BadModifier {
+
+	@Test
+	public void doSomethingWorks() {
+		// test here
+	}
+
+	@Test
+	private void doSomethingElseWorks() {
+		// test here
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/test/resources/source/JUnit5Valid.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * This is a valid example.
+ *
+ * @author Phillip Webb
+ */
+public class JUnit5Valid {
+
+	@Test
+	void doSomethingWorks() {
+		// test here
+	}
+
+}