HV-1921 Create a tester library for constraint validators with dependency injection

Author: shark300

documentation/pom.xml

@@ -34,7 +34,7 @@
         <!-- Skip artifact deployment -->
         <maven.deploy.skip>true</maven.deploy.skip>
         <gpg.skip>true</gpg.skip>
-        <surefire.jvm.args.additional>-Duser.language=en -Duser.country=US</surefire.jvm.args.additional>
+        <surefire.jvm.args.additional>--add-opens java.base/java.lang=ALL-UNNAMED -Duser.language=en -Duser.country=US</surefire.jvm.args.additional>
 
         <forbiddenapis-junit.path>forbidden-allow-junit.txt</forbiddenapis-junit.path>
         <hibernate-validator-parent.path>..</hibernate-validator-parent.path>
@@ -97,6 +97,11 @@
             <artifactId>junit</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.easymock</groupId>
+            <artifactId>easymock</artifactId>
+            <scope>test</scope>
+        </dependency>
         <!-- Only use assertj when strictly necessary in the documentation tests -->
         <dependency>
             <groupId>org.assertj</groupId>

documentation/src/main/asciidoc/ch06.asciidoc

@@ -323,6 +323,61 @@ include::{sourcedir}/org/hibernate/validator/referenceguide/chapter06/CarTest.ja
 ----
 ====
 
+[[validator-dependency-testing]]
+==== Testing constraint validator with dependencies
+
+Some DI frameworks (e.g. Spring) are capable of injecting dependencies into constraint validator instance:
+
+[[example-person-with-checkcase]]
+.Hibernate Validator test utilities Maven dependency
+====
+[source, XML]
+[subs="verbatim,attributes"]
+----
+<dependency>
+    <groupId>org.hibernate.validator</groupId>
+    <artifactId>hibernate-validator-test-utils</artifactId>
+    <version>{hvVersion}</version>
+    <scope>test</scope>
+</dependency>
+----
+====
+
+.Defining the `@ZipCode` constraint annotation
+====
+[source, JAVA, indent=0]
+----
+include::{sourcedir}/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/ZipCode.java[tags=include]
+----
+====
+
+.Applying the `@ZipCode` constraint
+====
+[source, JAVA, indent=0]
+----
+include::{sourcedir}/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/Person.java[tags=include]
+----
+====
+
+.Using injected dependency in a constraint validator
+====
+[source, JAVA, indent=0]
+----
+include::{sourcedir}/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/ZipCodeValidator.java[tags=include]
+----
+====
+
+Finally, <<example-using-validator-dependency>> demonstrates how validating a `Person` instance which calls custom mocked validator.
+
+[[example-using-validator-dependency]]
+.Validating objects with the `@ZipCode` constraint
+====
+[source, JAVA, indent=0]
+----
+include::{sourcedir}/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/CustomValidatorWithDependencyTest.java[tags=field]
+----
+====
+
 [[section-class-level-constraints]]
 === Class-level constraints
 

documentation/src/test/java/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/CustomValidatorWithDependencyTest.java

@@ -0,0 +1,56 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.validator.referenceguide.chapter06.customvalidatorwithdependency;
+
+import static org.easymock.EasyMock.eq;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.isA;
+import static org.easymock.EasyMock.mock;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
+import static org.junit.Assert.assertEquals;
+
+import java.util.Map;
+import java.util.Set;
+
+import jakarta.validation.ConstraintValidatorContext;
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.Validator;
+import jakarta.validation.ValidatorFactory;
+
+import org.hibernate.validator.testutil.PreconfiguredValidatorsValidatorFactory;
+
+import org.junit.Test;
+
+@SuppressWarnings("unused")
+//tag::field[]
+public class CustomValidatorWithDependencyTest {
+
+	@Test
+	public void mockCustomValidatorWithDependency() {
+		ZipCodeValidator zipCodeValidator = mock( ZipCodeValidator.class );
+
+		expect( zipCodeValidator.isValid( eq( "1234" ), isA( ConstraintValidatorContext.class ) ) )
+				.andStubReturn( true );
+		zipCodeValidator.initialize( isA( ZipCode.class ) );
+
+		replay( zipCodeValidator );
+
+		ValidatorFactory validatorFactory = PreconfiguredValidatorsValidatorFactory.builder()
+				.defaultValidators( Map.of( ZipCodeValidator.class, zipCodeValidator ) )
+				.build();
+
+		Validator validator = validatorFactory.getValidator();
+
+		Person person = new Person( "1234" );
+
+		Set<ConstraintViolation<Person>> constraintViolations = validator.validate( person );
+
+		assertEquals( 0, constraintViolations.size() );
+
+		verify( zipCodeValidator );
+	}
+}
+//end::field[]

documentation/src/test/java/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/Person.java

@@ -0,0 +1,17 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+//tag::include[]
+package org.hibernate.validator.referenceguide.chapter06.customvalidatorwithdependency;
+
+public class Person {
+
+	@ZipCode
+	private String zipCode;
+
+	public Person(String zipCode) {
+		this.zipCode = zipCode;
+	}
+}
+//end::include[]

documentation/src/test/java/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/ZipCode.java

@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+//tag::include[]
+package org.hibernate.validator.referenceguide.chapter06.customvalidatorwithdependency;
+
+import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE_USE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import jakarta.validation.Constraint;
+import jakarta.validation.Payload;
+
+//tag::include[]
+@Target({ METHOD, FIELD, ANNOTATION_TYPE, TYPE_USE })
+@Retention(RUNTIME)
+@Constraint(validatedBy = ZipCodeValidator.class)
+@Documented
+public @interface ZipCode {
+
+	String message() default "{org.hibernate.validator.referenceguide.chapter06." +
+			"customvalidatorwithdependency.ZipCode.message}";
+
+	Class<?>[] groups() default { };
+
+	Class<? extends Payload>[] payload() default { };
+}
+//end::include[]

documentation/src/test/java/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/ZipCodeRepository.java

@@ -0,0 +1,9 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.validator.referenceguide.chapter06.customvalidatorwithdependency;
+
+public interface ZipCodeRepository {
+	boolean isExist(String zipCode);
+}

documentation/src/test/java/org/hibernate/validator/referenceguide/chapter06/customvalidatorwithdependency/ZipCodeValidator.java

@@ -0,0 +1,29 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+//tag::include[]
+package org.hibernate.validator.referenceguide.chapter06.customvalidatorwithdependency;
+
+//end::include[]
+
+import jakarta.inject.Inject;
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorContext;
+
+//tag::include[]
+public class ZipCodeValidator implements ConstraintValidator<ZipCode, String> {
+
+	@Inject
+	public ZipCodeRepository zipCodeRepository;
+
+	@Override
+	public boolean isValid(String zipCode, ConstraintValidatorContext constraintContext) {
+		if ( zipCode == null ) {
+			return true;
+		}
+
+		return zipCodeRepository.isExist( zipCode );
+	}
+}
+//end::include[]

test-utils/src/main/java/org/hibernate/validator/testutil/PreconfiguredConstraintValidatorFactory.java

@@ -0,0 +1,66 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.validator.testutil;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorFactory;
+
+public class PreconfiguredConstraintValidatorFactory implements ConstraintValidatorFactory {
+
+	private final Map<Class<? extends ConstraintValidator>, ConstraintValidator<?, ?>> defaultValidators;
+	private final ConstraintValidatorFactory delegated;
+
+	private PreconfiguredConstraintValidatorFactory(Builder builder) {
+		this.defaultValidators = builder.defaultValidators;
+		this.delegated = builder.delegated;
+	}
+
+	public static Builder builder() {
+		return new Builder();
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public <T extends ConstraintValidator<?, ?>> T getInstance(Class<T> key) {
+		if ( defaultValidators.containsKey( key ) ) {
+			return (T) defaultValidators.get( key );
+		}
+
+		return delegated.getInstance( key );
+	}
+
+	@Override
+	public void releaseInstance(ConstraintValidator<?, ?> instance) {
+		delegated.releaseInstance( instance );
+	}
+
+	public static class Builder {
+
+		private ConstraintValidatorFactory delegated;
+		private final Map<Class<? extends ConstraintValidator>, ConstraintValidator<?, ?>> defaultValidators = new HashMap<>();
+
+		private Builder() {
+		}
+
+		public Builder defaultValidators(
+				Map<Class<? extends ConstraintValidator>, ConstraintValidator<?, ?>> validators) {
+			this.defaultValidators.putAll( validators );
+			return this;
+		}
+
+		public Builder delegated(
+				ConstraintValidatorFactory delegated) {
+			this.delegated = delegated;
+			return this;
+		}
+
+		public PreconfiguredConstraintValidatorFactory build() {
+			return new PreconfiguredConstraintValidatorFactory( this );
+		}
+	}
+}