Optionally ban JUnit 4 imports

README.md

@@ -90,6 +90,12 @@ You can set up `mvn spotless:apply` to run automatically (in `validate` phase) f
 </settings>
 ```
 
+## Additional Checks
+
+You can set the `ban-junit4-imports.skip` to `false` if your tests are written with JUnit 5 (Jupiter) and you want to ensure that no JUnit 4 imports are used in your plugin.
+This will prevent imports of JUnit 4 classes in your code to ensure newly added or improved tests do not reintroduce JUnit 4 (e.g., out of habit or from IDE import autocompletion).
+Note that this will only address imports of JUnit 4 in your code, and not uses from dependencies.
+
 ## Running Benchmarks
 
 To run JMH benchmarks from JUnit tests, activate the `benchmark`

pom.xml

@@ -151,6 +151,9 @@
     <!-- Set to false to enable Spotless -->
     <spotless.check.skip>true</spotless.check.skip>
 
+    <!-- Set to false to enable enforcer banning org.junit.* imports -->
+    <ban-junit4-imports.skip>true</ban-junit4-imports.skip>
+
     <!-- Whether to skip tests during release phase (they are executed in the prepare phase). -->
     <release.skipTests>true</release.skipTests>
     <!-- By default we do not create *-tests.jar. Set to false to allow other plugins to depend on test utilities in yours, using <classifier>tests</classifier>. -->
@@ -533,6 +536,11 @@
             <artifactId>extra-enforcer-rules</artifactId>
             <version>1.9.0</version>
           </dependency>
+          <dependency>
+            <groupId>de.skuzzle.enforcer</groupId>
+            <artifactId>restrict-imports-enforcer-rule</artifactId>
+            <version>2.6.1</version>
+          </dependency>
         </dependencies>
         <executions>
           <execution>
@@ -658,6 +666,23 @@
               </rules>
             </configuration>
           </execution>
+          <execution>
+            <id>check-junit-imports</id>
+            <goals>
+              <goal>enforce</goal>
+            </goals>
+            <phase>process-sources</phase>
+            <configuration>
+              <rules>
+                <RestrictImports>
+                  <reason>Use JUnit 5 (org.junit.jupiter.*)</reason>
+                  <bannedImport>org.junit.**</bannedImport>
+                  <allowedImport>org.junit.jupiter.**</allowedImport>
+                </RestrictImports>
+              </rules>
+              <skip>${ban-junit4-imports.skip}</skip>
+            </configuration>
+          </execution>
         </executions>
       </plugin>
       <plugin>

src/it/ban-juni4-fail/invoker.properties

@@ -0,0 +1,2 @@
+invoker.goals=-Dstyle.color=always -ntp verify
+invoker.buildResult=failure

src/it/ban-juni4-fail/pom.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.jenkins-ci.plugins</groupId>
+        <artifactId>plugin</artifactId>
+        <version>@project.version@</version>
+        <relativePath />
+    </parent>
+    <groupId>org.jenkins-ci.plugins.its</groupId>
+    <artifactId>ban-junit4-fail-it</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>hpi</packaging>
+    <properties>
+        <jenkins.version>2.479.3</jenkins.version>
+        <ban-junit4-imports.skip>false</ban-junit4-imports.skip>
+    </properties>
+    <repositories>
+        <repository>
+            <id>repo.jenkins-ci.org</id>
+            <url>https://repo.jenkins-ci.org/public/</url>
+        </repository>
+    </repositories>
+    <pluginRepositories>
+        <pluginRepository>
+            <id>repo.jenkins-ci.org</id>
+            <url>https://repo.jenkins-ci.org/public/</url>
+        </pluginRepository>
+    </pluginRepositories>
+</project>

src/it/ban-juni4-fail/postbuild.groovy

@@ -0,0 +1,12 @@
+// Build failed
+def hpi = new File(basedir, 'target/ban-junit4-fail-it.jar')
+assert !hpi.exists()
+
+// Because of banned imports
+def log = new File(basedir, 'build.log')
+assert log.text.contains('Reason: Use JUnit 5 (org.junit.jupiter.*)')
+assert log.text.contains('org.junit.Test')
+assert log.text.contains('(Line: 3, Matched by: org.junit.**)')
+assert log.text.contains('static org.junit.Assert.assertTrue')
+assert log.text.contains('(Line: 5, Matched by: org.junit.**)')
+return true

src/it/ban-juni4-fail/src/main/resources/index.jelly

@@ -0,0 +1,2 @@
+<?jelly escape-by-default='true'?>
+<div/>

src/it/ban-juni4-fail/src/test/java/banjunit4/BanJUnit4FailTest.java

@@ -0,0 +1,12 @@
+package banjunit4;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+public class BanJUnit4FailTest {
+    @Test
+    public void thisFails() {
+        assertTrue(true);
+    }
+}

src/it/ban-junit4-pass/invoker.properties

@@ -0,0 +1 @@
+invoker.goals=-Dstyle.color=always -ntp verify

src/it/ban-junit4-pass/pom.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.jenkins-ci.plugins</groupId>
+        <artifactId>plugin</artifactId>
+        <version>@project.version@</version>
+        <relativePath />
+    </parent>
+    <groupId>org.jenkins-ci.plugins.its</groupId>
+    <artifactId>ban-junit4-pass-it</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>hpi</packaging>
+    <properties>
+        <jenkins.version>2.479.3</jenkins.version>
+        <ban-junit4-imports.skip>false</ban-junit4-imports.skip>
+    </properties>
+    <repositories>
+        <repository>
+            <id>repo.jenkins-ci.org</id>
+            <url>https://repo.jenkins-ci.org/public/</url>
+        </repository>
+    </repositories>
+    <pluginRepositories>
+        <pluginRepository>
+            <id>repo.jenkins-ci.org</id>
+            <url>https://repo.jenkins-ci.org/public/</url>
+        </pluginRepository>
+    </pluginRepositories>
+</project>

src/it/ban-junit4-pass/postbuild.groovy

@@ -0,0 +1,10 @@
+// Build passes
+def hpi = new File(basedir, 'target/ban-junit4-pass-it.jar')
+assert hpi.exists()
+
+def log = new File(basedir, 'build.log')
+assert !log.text.contains('org.junit.Test')
+assert !log.text.contains('(Line: 3, Matched by: org.junit.**)')
+assert !log.text.contains('static org.junit.Assert.assertTrue')
+assert !log.text.contains('(Line: 5, Matched by: org.junit.**)')
+return true

src/it/ban-junit4-pass/src/main/resources/index.jelly

@@ -0,0 +1,2 @@
+<?jelly escape-by-default='true'?>
+<div/>

src/it/ban-junit4-pass/src/test/java/banjunit4/BanJUnit4PassTest.java

@@ -0,0 +1,12 @@
+package banjunit4;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class BanJUnit4PassTest {
+    @Test
+    public void thisFails() {
+        assertTrue(true);
+    }
+}