Java: add single-method class test case for mocking rule

Classes with only one public method should be compliant when mocked.

Author: Napalys

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

@@ -0,0 +1,9 @@
+/**
+ * Simple class with a single public method to test the edge case.
+ * When this single method is mocked, it means ALL public methods are mocked.
+ */
+public class EmployeeStatus {
+    public String getStatus() {
+        return "active";
+    }
+}

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

@@ -1,2 +1,3 @@
 | 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

@@ -52,4 +52,14 @@ public void nonCompliant2() { // $ Alert
     doReturn(0).when(employeeRecordMock).update(sampleEmployee, "Jane Doe"); // Mocked EmployeeRecord.update
     doReturn(0).when(employeeRecordMock).delete(sampleEmployee); // Mocked EmployeeRecord.delete
   }
+
+  /**
+   * Edge case: Class with single public method - should NOT be flagged.
+   * When there's only one public method, mocking it doesn't indicate a "too big" test.
+   */
+  @Test
+  public void compliantSingleMethod() { // $ SPURIOUS: Alert
+    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)
+  }
 }