Java: exclude single-method classes from mocking

Author: Napalys

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

@@ -62,6 +62,8 @@ where
   exists(MockitoMockCall mockCall |
     mockCall.getParent+().(Stmt) = testMethod.getBody().getAStmt() and
     mockedClassOrInterface = mockCall.getMockedType() and
+    // Only flag classes with multiple public methods (2 or more)
+    count(Method m | m = mockedClassOrInterface.getAMethod() and m.isPublic()) > 1 and
     forex(Method method | method = mockedClassOrInterface.getAMethod() and method.isPublic() |
       exists(MockitoMockingMethodCall mockedMethod |
         mockedMethod.getMockitoMockCall() = mockCall and

java/ql/test/query-tests/MockingAllNonPrivateMethodsMeansUnitTestIsTooBig/MockingAllNonPrivateMethodsMeansUnitTestIsTooBig.expected

@@ -1,3 +1,2 @@
 | TestORM.java:34:15:34:27 | nonCompliant1 | This test method mocks all public methods of a $@. | EmployeeRecord.java:4:14:4:27 | EmployeeRecord | class or an interface |
 | TestORM.java:47:15:47:27 | nonCompliant2 | This test method mocks all public methods of a $@. | EmployeeRecord.java:4:14:4:27 | EmployeeRecord | class or an interface |
-| TestORM.java:61:15:61:35 | compliantSingleMethod | This test method mocks all public methods of a $@. | EmployeeStatus.java:5:14:5:27 | EmployeeStatus | class or an interface |

java/ql/test/query-tests/MockingAllNonPrivateMethodsMeansUnitTestIsTooBig/TestORM.java

@@ -58,7 +58,7 @@ public void nonCompliant2() { // $ Alert
    * When there's only one public method, mocking it doesn't indicate a "too big" test.
    */
   @Test
-  public void compliantSingleMethod() { // $ SPURIOUS: Alert
+  public void compliantSingleMethod() {
     EmployeeStatus statusMock = mock(EmployeeStatus.class); // COMPLIANT: Single public method, no choice but to mock it if needed
     when(statusMock.getStatus()).thenReturn("inactive"); // Mocked EmployeeStatus.getStatus (the only public method, but that's OK)
   }