Java: refactor QL

Author: Jami Cogswell

java/ql/lib/semmle/code/java/UnitTests.qll

@@ -112,6 +112,14 @@ class JUnitJupiterTestMethod extends Method {
   }
 }
 
+/**
+ * A JUnit test class that contains at least one method annotated with
+ * `org.junit.jupiter.api.Test`.
+ */
+class JUnit5TestClass extends Class {
+  JUnit5TestClass() { this.getAMethod() instanceof JUnitJupiterTestMethod }
+}
+
 /**
  * A JUnit `@Ignore` annotation.
  */

java/ql/src/Likely Bugs/Frameworks/JUnit/JUnit5NonStaticInnerClassMissingNestedAnnotation.ql

@@ -1,30 +1,22 @@
 /**
  * @id java/junit5-non-static-inner-class-missing-nested-annotation
- * @name J-T-004: Non-static inner class defined in a JUnit5 test is missing a `@Nested` annotation
- * @description A non-static inner class defined in a JUnit5 test missing a `@Nested` annotation
+ * @name Non-static inner class defined in a JUnit 5 test is missing a `@Nested` annotation
+ * @description A non-static inner class defined in a JUnit 5 test missing a `@Nested` annotation
  *              will be excluded from execution and it may indicate a misunderstanding from the
  *              programmer.
  * @kind problem
  * @precision very-high
  * @problem.severity warning
- * @tags maintainability
+ * @tags quality
+ *       maintainability
  *       correctness
  */
 
 import java
 
-class JUnit5TestClass extends Class {
-  JUnit5TestClass() {
-    this.getAMethod().getAnAnnotation().getType().hasQualifiedName("org.junit.jupiter.api", "Test")
-  }
-}
-
-from JUnit5TestClass testClass // `TestClass` by definition should have at least one @Test method.
+from JUnit5TestClass testClass
 where
-  not testClass.isStatic() and
-  testClass instanceof InnerClass and // `InnerClass` is by definition a non-static nested class.
-  not exists(Annotation annotation |
-    annotation.getType().hasQualifiedName("org.junit.jupiter.api", "Nested") and
-    annotation.getAnnotatedElement() = testClass
-  )
-select testClass, "This JUnit5 inner test class lacks a @Nested annotation."
+  // `InnerClass` is a non-static, nested class.
+  testClass instanceof InnerClass and
+  not testClass.hasAnnotation("org.junit.jupiter.api", "Nested")
+select testClass, "This JUnit5 inner test class lacks a '@Nested' annotation."