feat: flamingock test support DefaultExceptionValidator (#764)

Author: davidfrigolet

core/flamingock-test-support/src/main/java/io/flamingock/support/validation/impl/AuditSequenceStrictValidator.java

@@ -70,20 +70,15 @@ public AuditSequenceStrictValidator(AuditReader auditReader, AuditEntryDefinitio
     public ValidationResult validate() {
         List<ValidationError> allErrors = new ArrayList<>();
 
-        int expectedSize = expectations.size();
-        int actualSize = actualEntries.size();
-
-        if (expectedSize != actualSize) {
+        if (expectations.size() != actualEntries.size()) {
             allErrors.add(new CountMismatchError(getExpectedChangeIds(), getActualChangeIds()));
         }
 
         allErrors.addAll(getValidationErrors(expectations, actualEntries));
 
-        if (allErrors.isEmpty()) {
-            return ValidationResult.success(VALIDATOR_NAME);
-        }
-
-        return ValidationResult.failure(VALIDATOR_NAME, allErrors.toArray(new ValidationError[0]));
+        return allErrors.isEmpty()
+          ? ValidationResult.success(VALIDATOR_NAME)
+          : ValidationResult.failure(VALIDATOR_NAME, allErrors.toArray(new ValidationError[0]));
     }
 
     private static List<ValidationError> getValidationErrors(List<AuditEntryExpectation> expectedEntries, List<AuditEntry> actualEntries) {

core/flamingock-test-support/src/main/java/io/flamingock/support/validation/impl/DefaultExceptionValidator.java

@@ -16,6 +16,8 @@
 package io.flamingock.support.validation.impl;
 
 import io.flamingock.support.validation.ExceptionValidator;
+import io.flamingock.support.validation.error.ExceptionNotExpectedError;
+import io.flamingock.support.validation.error.ExceptionTypeMismatchError;
 import io.flamingock.support.validation.error.ValidationResult;
 
 import java.util.function.Consumer;
@@ -40,7 +42,30 @@ public void setActualException(Throwable actualException) {
 
     @Override
     public ValidationResult validate(Throwable actualException) {
-        // TODO: Implement actual validation logic
+        // No exception expected
+        if (expectedExceptionClass == null) {
+            if (actualException == null) {
+                return ValidationResult.success(VALIDATOR_NAME);
+            } else {
+                return ValidationResult.failure(VALIDATOR_NAME, new ExceptionNotExpectedError(actualException));
+            }
+        }
+
+        // An exception is expected but none was thrown
+        if (actualException == null) {
+            return ValidationResult.failure(VALIDATOR_NAME,
+                    new ExceptionTypeMismatchError(expectedExceptionClass, null));
+        }
+
+        // Type mismatch
+        if (!expectedExceptionClass.isInstance(actualException)) {
+            return ValidationResult.failure(VALIDATOR_NAME,
+                    new ExceptionTypeMismatchError(expectedExceptionClass, actualException.getClass()));
+        }
+
+        if (expectedExceptionConsumer != null) {
+            expectedExceptionConsumer.accept(actualException);
+        }
         return ValidationResult.success(VALIDATOR_NAME);
     }
 }

core/flamingock-test-support/src/test/java/io/flamingock/support/validation/impl/DefaultExceptionValidatorTest.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2025 Flamingock (https://www.flamingock.io)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.flamingock.support.validation.impl;
+
+import io.flamingock.support.validation.error.ExceptionNotExpectedError;
+import io.flamingock.support.validation.error.ExceptionTypeMismatchError;
+import io.flamingock.support.validation.error.ValidationResult;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class DefaultExceptionValidatorTest {
+
+    @Test
+    @DisplayName("DefaultExceptionValidatorTest: No exception expected and none thrown — should succeed")
+    void noExceptionExpected_andNoneThrown_shouldSucceed() {
+        DefaultExceptionValidator validator = new DefaultExceptionValidator(null, null);
+        ValidationResult result = validator.validate(null);
+        assertTrue(result.isSuccess());
+        assertFalse(result.hasErrors());
+    }
+
+    @Test
+    @DisplayName("DefaultExceptionValidatorTest: No exception expected but an exception thrown — should fail with ExceptionNotExpectedError")
+    void noExceptionExpected_butExceptionThrown_shouldFailWithNotExpected() {
+        DefaultExceptionValidator validator = new DefaultExceptionValidator(null, null);
+        RuntimeException ex = new RuntimeException("message");
+        ValidationResult result = validator.validate(ex);
+        assertTrue(result.hasErrors());
+        assertFalse(result.isSuccess());
+        assertEquals(1, result.getErrors().size());
+        assertInstanceOf(ExceptionNotExpectedError.class, result.getErrors().get(0));
+    }
+
+    @Test
+    @DisplayName("DefaultExceptionValidatorTest: Exception expected but none thrown — should fail with ExceptionTypeMismatchError (null actual)")
+    void exceptionExpected_butNoneThrown_shouldFailWithTypeMismatch_nullActual() {
+        DefaultExceptionValidator validator = new DefaultExceptionValidator(IOException.class, null);
+        ValidationResult result = validator.validate(null);
+        assertTrue(result.hasErrors());
+        assertEquals(1, result.getErrors().size());
+        assertInstanceOf(ExceptionTypeMismatchError.class, result.getErrors().get(0));
+    }
+
+    @Test
+    @DisplayName("DefaultExceptionValidatorTest: Exception expected but wrong type thrown — should fail with ExceptionTypeMismatchError")
+    void exceptionExpected_butWrongTypeThrown_shouldFailWithTypeMismatch() {
+        DefaultExceptionValidator validator = new DefaultExceptionValidator(IllegalArgumentException.class, null);
+        RuntimeException ex = new RuntimeException("message");
+        ValidationResult result = validator.validate(ex);
+        assertTrue(result.hasErrors());
+        assertEquals(1, result.getErrors().size());
+        assertInstanceOf(ExceptionTypeMismatchError.class, result.getErrors().get(0));
+    }
+
+    @Test
+    @DisplayName("DefaultExceptionValidatorTest: Exception expected and correct type thrown — should succeed and invoke consumer")
+    void exceptionExpected_andCorrectTypeThrown_shouldSucceed_andInvokeConsumer() {
+        AtomicBoolean consumed = new AtomicBoolean(false);
+        DefaultExceptionValidator validator = new DefaultExceptionValidator(RuntimeException.class, e -> consumed.set(true));
+        RuntimeException ex = new RuntimeException("message");
+        ValidationResult result = validator.validate(ex);
+        assertTrue(result.isSuccess());
+        assertFalse(result.hasErrors());
+        assertTrue(consumed.get());
+    }
+}