Add Junit custom annotation to validate record mandatory fields

Author: tejada7

boot-examples/pom.xml

@@ -23,6 +23,8 @@
         <openapi-generator-maven-plugin.version>7.0.1</openapi-generator-maven-plugin.version>
         <wiremock-jre8.version>3.0.1</wiremock-jre8.version>
         <awaitility.version>4.2.1</awaitility.version>
+        <instancio-junit.version>5.3.0</instancio-junit.version>
+        <spring-boot-testjars.version>0.0.1</spring-boot-testjars.version>
     </properties>
     <dependencies>
         <dependency>
@@ -96,15 +98,22 @@
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-dependencies</artifactId>
-            <version>3.3.1</version>
+            <version>3.4.2</version>
             <type>pom</type>
             <scope>import</scope>
         </dependency>
         <dependency>
             <groupId>org.springframework.experimental.boot</groupId>
             <artifactId>spring-boot-testjars</artifactId>
-            <version>0.0.1</version>
+            <version>${spring-boot-testjars.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.instancio</groupId>
+            <artifactId>instancio-junit</artifactId>
+            <version>${instancio-junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+
     </dependencies>
 
     <build>

boot-examples/src/test/java/com/ftm/vcp/bootexamples/domain/FooTest.java

@@ -0,0 +1,47 @@
+package com.ftm.vcp.bootexamples.domain;
+
+import com.ftm.vcp.bootexamples.testutils.DomainRecordFieldProvider;
+import com.ftm.vcp.bootexamples.testutils.SetContextExtension;
+import com.ftm.vcp.bootexamples.testutils.SetGenericContext;
+import org.instancio.Instancio;
+import org.instancio.Select;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.IndicativeSentencesGeneration;
+import org.junit.jupiter.api.TestInstance;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ArgumentsSource;
+
+import static org.assertj.core.api.Assertions.catchThrowable;
+import static org.assertj.core.api.BDDAssertions.then;
+import static org.junit.jupiter.api.DisplayNameGenerator.IndicativeSentences;
+import static org.junit.jupiter.api.DisplayNameGenerator.ReplaceUnderscores;
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+@DisplayName("A Foo")
+@DisplayNameGeneration(IndicativeSentences.class)
+@IndicativeSentencesGeneration(separator = " ", generator = ReplaceUnderscores.class)
+@SetGenericContext(
+    value = Foo.class,
+    errorMessagePattern = "%s cannot be null"
+)
+class FooTest {
+
+//    @RegisterExtension
+//    private static final SetContextExtension customExtension = new SetContextExtension(
+//        Foo.class, "%s cannot be null");
+
+    @ParameterizedTest(name = "{0}=null, expectedErrorMessage={1}")
+    @ArgumentsSource(DomainRecordFieldProvider.class)
+    void should_not_contain_invalid_values(String field, String expectedMessage) {
+        then(catchThrowable(() -> Instancio.of(Foo.class)
+            .ignore(Select.field(field))
+            .create())
+        )
+            .hasRootCauseInstanceOf(NullPointerException.class)
+            .hasRootCauseMessage(expectedMessage);
+        ;
+    }
+
+}

boot-examples/src/test/java/com/ftm/vcp/bootexamples/testutils/DomainRecordFieldProvider.java

@@ -0,0 +1,31 @@
+package com.ftm.vcp.bootexamples.testutils;
+
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.ArgumentsProvider;
+
+import java.lang.reflect.RecordComponent;
+import java.util.Arrays;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+/**
+ * Generates arguments as number of fields for a given record, along with an expected error message
+ */
+public class DomainRecordFieldProvider implements ArgumentsProvider {
+
+    @Override
+    public Stream<? extends Arguments> provideArguments(ExtensionContext context) {
+        final Class<?> contextType = (Class<?>) context.getStore(ExtensionContext.Namespace.GLOBAL).get("contextType");
+        final String errorMessagePattern = (String) context.getStore(ExtensionContext.Namespace.GLOBAL).get("errorMessagePattern");
+        return Arrays.stream(contextType.getRecordComponents())
+            .map(RecordComponent::getName)
+            .map(fieldName -> new Object() {
+                final String field = fieldName;
+                final String expectedMessage = Optional.ofNullable(errorMessagePattern)
+                    .map(string -> string.formatted(field))
+                    .orElseGet(() -> fieldName + " cannot be null");
+            })
+            .map(result -> Arguments.arguments(result.field, result.expectedMessage));
+    }
+}

boot-examples/src/test/java/com/ftm/vcp/bootexamples/testutils/SetContextExtension.java

@@ -0,0 +1,57 @@
+package com.ftm.vcp.bootexamples.testutils;
+
+import org.junit.jupiter.api.extension.BeforeAllCallback;
+import org.junit.jupiter.api.extension.Extension;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.params.provider.ArgumentsProvider;
+import org.junit.platform.commons.support.AnnotationSupport;
+
+/**
+ * Extension allowing to transmit a context (e.g. a generic clas type) to a custom {@link ArgumentsProvider}.
+ */
+public class SetContextExtension implements BeforeAllCallback, Extension {
+
+    private final Class<?> contextType;
+    private final String errorMessagePattern;
+
+    /**
+     * Used when using
+     * <code>
+     *
+     * @param contextType         the context type to set before running the unit test
+     * @param errorMessagePattern the expected error message pattern
+     * @RegisterExtension private static final InvalidRecordConstructionExtension customExtension = new InvalidRecordConstructionExtension(Foo.class);
+     * </code>
+     */
+    public SetContextExtension(Class<?> contextType, String errorMessagePattern) {
+        this.contextType = contextType;
+        this.errorMessagePattern = errorMessagePattern;
+    }
+
+    /**
+     * Used by the {@link SetGenericContext} annotation
+     */
+    public SetContextExtension() {
+        contextType = null;
+        errorMessagePattern = null;
+    }
+
+    @Override
+    public void beforeAll(ExtensionContext context) {
+        final Class<?> recordType = context.getElement()
+            .flatMap((annotatedElement) -> AnnotationSupport
+                .findAnnotation(annotatedElement, SetGenericContext.class))
+            .<Class<?>>map(SetGenericContext::value)
+            .orElseGet(() -> contextType);
+        context.getStore(ExtensionContext.Namespace.GLOBAL)
+            .put("contextType", recordType);
+
+        final String messagePattern = context.getElement()
+            .flatMap((annotatedElement) -> AnnotationSupport
+                .findAnnotation(annotatedElement, SetGenericContext.class))
+            .map(SetGenericContext::errorMessagePattern)
+            .orElseGet(() -> errorMessagePattern);
+        context.getStore(ExtensionContext.Namespace.GLOBAL)
+            .put("errorMessagePattern", messagePattern);
+    }
+}

boot-examples/src/test/java/com/ftm/vcp/bootexamples/testutils/SetGenericContext.java

@@ -0,0 +1,17 @@
+package com.ftm.vcp.bootexamples.testutils;
+
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.TYPE})
+@Retention(RetentionPolicy.RUNTIME)
+@ExtendWith(SetContextExtension.class)
+public @interface SetGenericContext {
+    Class<?> value();
+
+    String errorMessagePattern() default "%s is mandatory";
+}

boot-examples/src/test/resources/instancio.properties

@@ -0,0 +1 @@
+fail.on.error=true