Add Validator.check() methods that return Set<ConstraintViolation> rather than throw

Technically we might not need this but I think it could be useful for applications that want to pre-validate messages before sending them etc.

Author: rbygrave

blackbox-test/src/test/java/example/avaje/length/ALengthTest.java

@@ -16,6 +16,24 @@ class ALengthTest {
 
   final Validator validator = Validator.builder().addLocales(Locale.GERMAN).build();
 
+  @Test
+  void check() {
+    var violations = validator.check(new ALength("ok", "ok", "ok", "ok"));
+    assertThat(violations).isEmpty();
+  }
+
+  @Test
+  void checkOne() {
+    var violations = validator.check(new ALength("", "ok", "ok", "ok"));
+    assertThat(violations).hasSize(1);
+  }
+
+  @Test
+  void checkMulti() {
+    var violations = validator.check(new ALength("", "123456", "e", "e"));
+    assertThat(violations).hasSize(4);
+  }
+
   @Test
   void valid() {
     var cust = new ALength("ok", "ok", "ok", "ok");

validator/src/main/java/io/avaje/validation/Validator.java

@@ -6,6 +6,7 @@
 import java.time.Duration;
 import java.util.Locale;
 import java.util.ResourceBundle;
+import java.util.Set;
 import java.util.function.Supplier;
 
 import io.avaje.lang.Nullable;
@@ -48,6 +49,27 @@ public interface Validator {
   void validate(Object any, @Nullable Locale locale, @Nullable Class<?>... groups)
       throws ConstraintViolationException;
 
+  /**
+   * Validate the object returning the constraint violations.
+   *
+   * @param any The object to validate
+   * @param groups The groups targeted for validation
+   *
+   * @return The constraint violations
+   */
+  Set<ConstraintViolation> check(Object any, @Nullable Class<?>... groups);
+
+  /**
+   * Validate the object returning the constraint violations.
+   *
+   * @param any The object to validate
+   * @param locale The locale to use for messages
+   * @param groups The groups targeted for validation
+   *
+   * @return The constraint violations
+   */
+  Set<ConstraintViolation> check(Object any, @Nullable Locale locale, @Nullable Class<?>... groups);
+
   /** Return the validation context used to create adapters */
   ValidationContext context();
 

validator/src/main/java/io/avaje/validation/adapter/ValidationRequest.java

@@ -1,7 +1,9 @@
 package io.avaje.validation.adapter;
 
 import java.util.List;
+import java.util.Set;
 
+import io.avaje.validation.ConstraintViolation;
 import io.avaje.validation.ConstraintViolationException;
 
 /** A validation request. */
@@ -27,6 +29,9 @@ public interface ValidationRequest {
   /** Throw ConstraintViolationException if there are violations in this request. */
   void throwWithViolations() throws ConstraintViolationException;
 
+  /** Return the violations */
+  Set<ConstraintViolation> violations();
+
   /** return true if there are violations in this request. */
   boolean hasViolations();
 }

validator/src/main/java/io/avaje/validation/core/DRequest.java

@@ -80,6 +80,11 @@ public void throwWithViolations() {
     }
   }
 
+  @Override
+  public Set<ConstraintViolation> violations() {
+    return violations;
+  }
+
   @Override
   public List<Class<?>> groups() {
     return groups;

validator/src/main/java/io/avaje/validation/core/DValidator.java

@@ -23,6 +23,7 @@
 import java.util.function.Supplier;
 
 import io.avaje.lang.Nullable;
+import io.avaje.validation.ConstraintViolation;
 import io.avaje.validation.Validator;
 import io.avaje.validation.adapter.ValidationAdapter;
 import io.avaje.validation.adapter.ValidationContext;
@@ -78,6 +79,18 @@ public void validate(Object any, @Nullable Locale locale, @Nullable Class<?>...
     type.validate(any, locale, List.of(groups));
   }
 
+  @Override
+  public Set<ConstraintViolation> check(Object any, @Nullable Class<?>... groups) {
+    return check(any, null, groups);
+  }
+
+  @Override
+  @SuppressWarnings("unchecked")
+  public Set<ConstraintViolation> check(Object any, @Nullable Locale locale, @Nullable Class<?>... groups) {
+    final var type = (ValidationType<Object>) type(any.getClass());
+    return type.check(any, locale, List.of(groups));
+  }
+
   @Override
   public ValidationContext context() {
     return this;

validator/src/main/java/io/avaje/validation/core/ValidationType.java

@@ -2,8 +2,10 @@
 
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 
 import io.avaje.lang.Nullable;
+import io.avaje.validation.ConstraintViolation;
 import io.avaje.validation.ConstraintViolationException;
 import io.avaje.validation.adapter.ValidationAdapter;
 import io.avaje.validation.adapter.ValidationContext;
@@ -13,15 +15,21 @@ final class ValidationType<T> {
   private final ValidationContext ctx;
   private final ValidationAdapter<T> adapter;
 
-  public ValidationType(ValidationContext validator, ValidationAdapter<T> adapter) {
+  ValidationType(ValidationContext validator, ValidationAdapter<T> adapter) {
     this.ctx = validator;
     this.adapter = adapter;
   }
 
-  public void validate(T object, @Nullable Locale locale, List<Class<?>> groups)
+  void validate(T object, @Nullable Locale locale, List<Class<?>> groups)
       throws ConstraintViolationException {
     final var req = ctx.request(locale, groups);
     adapter.validate(object, req);
     req.throwWithViolations();
   }
+
+  Set<ConstraintViolation> check(T object, @Nullable Locale locale, List<Class<?>> groups) {
+    final var req = ctx.request(locale, groups);
+    adapter.validate(object, req);
+    return req.violations();
+  }
 }