SONARJAVA-4446 Check if the parent class or implemented interface symbols of the test class are known. (#4956)

Author: erwan-serandour

its/autoscan/src/test/resources/autoscan/diffs/diff_S2187.json

@@ -1,6 +1,6 @@
 {
   "ruleKey": "S2187",
   "hasTruePositives": true,
-  "falseNegatives": 12,
-  "falsePositives": 1
+  "falseNegatives": 13,
+  "falsePositives": 0
 }

java-checks-test-sources/default/src/main/files/non-compiling/checks/NoTestInTestClassCheckSample.java

@@ -21,7 +21,6 @@
 import com.googlecode.zohhak.api.TestWith;
 import com.googlecode.zohhak.api.runners.ZohhakRunner;
 
-
 class A extends junit.framework.TestCase {
   void testFoo() {
   }
@@ -313,3 +312,16 @@ public class MyZohhak4Test { // Compliant
   public void testFoo4() {
   }
 }
+
+class SubclassTest extends UndefinedParent { // Compliant, we cannot know what is in ParentTestClass so we don't raise issues
+}
+
+class Subclass2Test extends myPackage.UndefinedParent {
+}
+
+class Subclass3Test implements UndefinedInterface {
+
+}
+
+abstract class ResolvedParent {}
+class Subclass4Test extends ResolvedParent {} // Noncompliant

java-checks/src/main/java/org/sonar/java/checks/tests/NoTestInTestClassCheck.java

@@ -20,6 +20,7 @@
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
@@ -78,7 +79,17 @@ private void resetAnnotationCache() {
   }
 
   private void checkClass(ClassTree classTree) {
-    if (!ModifiersUtils.hasModifier(classTree.modifiers(), Modifier.ABSTRACT)) {
+    boolean hasUnknownParent = Optional.ofNullable(classTree.superClass())
+      .map(parent -> parent.symbolType().isUnknown())
+      // If the superClass is null, then the class has no parent, so has no unknownParent.
+      .orElse(false);
+    boolean knownImplementedInterfaces = classTree.superInterfaces().stream()
+      .noneMatch(i -> i.symbolType().isUnknown());
+
+    if (!ModifiersUtils.hasModifier(classTree.modifiers(), Modifier.ABSTRACT)
+      && !hasUnknownParent
+      && knownImplementedInterfaces
+    ) {
       Symbol.TypeSymbol classSymbol = classTree.symbol();
       Stream<Symbol> members = getAllMembers(classSymbol, checkRunWith(classSymbol, "Enclosed"));
       IdentifierTree simpleName = classTree.simpleName();