add support for items keyword

core/pom.xml

@@ -167,6 +167,16 @@
                                         <inculde>**/tests/draft2019-09/multipleOf.json</inculde>
                                         <inculde>**/tests/draft2020-12/multipleOf.json</inculde>
                                         <inculde>**/tests/draft-next/multipleOf.json</inculde>
+
+                                        <!-- more than items keyword needed :(
+                                        <inculde>**/tests/draft3/items.json</inculde>
+                                        <inculde>**/tests/draft4/items.json</inculde>
+                                        <inculde>**/tests/draft6/items.json</inculde>
+                                        <inculde>**/tests/draft7/items.json</inculde>
+                                        <inculde>**/tests/draft2019-09/items.json</inculde>
+                                        <inculde>**/tests/draft2020-12/items.json</inculde>
+                                        <inculde>**/tests/draft-next/items.json</inculde>
+                                        -->
                                     </includes>
                                 </resource>
                             </resources>

core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/BasicVocabulary.java

@@ -46,7 +46,8 @@ public BasicVocabulary() {
                 new ExclusiveMinimumKeywordType(),
                 new MaximumKeywordType(),
                 new ExclusiveMaximumKeywordType(),
-                new MultipleOfKeywordType()
+                new MultipleOfKeywordType(),
+                new ItemsKeywordType()
             );
     }
 

core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/ItemsKeywordType.java

@@ -0,0 +1,82 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2023 sebastian.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package io.github.sebastiantoepfer.jsonschema.core.vocab.basic;
+
+import io.github.sebastiantoepfer.jsonschema.ConstraintViolation;
+import io.github.sebastiantoepfer.jsonschema.InstanceType;
+import io.github.sebastiantoepfer.jsonschema.JsonSchema;
+import io.github.sebastiantoepfer.jsonschema.JsonSchemas;
+import io.github.sebastiantoepfer.jsonschema.Validator;
+import io.github.sebastiantoepfer.jsonschema.core.vocab.ConstraintAssertion;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
+import io.github.sebastiantoepfer.jsonschema.keyword.KeywordType;
+import jakarta.json.JsonArray;
+import jakarta.json.JsonValue;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+final class ItemsKeywordType implements KeywordType {
+
+    @Override
+    public String name() {
+        return "items";
+    }
+
+    @Override
+    public Keyword createKeyword(final JsonValue value) {
+        return new ItemsKeyword(JsonSchemas.load(value));
+    }
+
+    private class ItemsKeyword implements ConstraintAssertion {
+
+        private final JsonSchema schema;
+
+        public ItemsKeyword(final JsonSchema schema) {
+            this.schema = schema;
+        }
+
+        @Override
+        public boolean hasName(final String name) {
+            return Objects.equals(name(), name);
+        }
+
+        @Override
+        public Collection<ConstraintViolation> violationsBy(final JsonValue value) {
+            final Collection<ConstraintViolation> result;
+            if (!InstanceType.ARRAY.isInstance(value) || matchesSchema(value.asJsonArray())) {
+                result = Collections.emptyList();
+            } else {
+                result = List.of(new ConstraintViolation());
+            }
+            return result;
+        }
+
+        private boolean matchesSchema(final JsonArray items) {
+            final Validator itemValidator = schema.validator();
+            return items.stream().map(itemValidator::validate).allMatch(Collection::isEmpty);
+        }
+    }
+}

core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/ItemsKeywordTypeTest.java

@@ -0,0 +1,65 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2023 sebastian.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package io.github.sebastiantoepfer.jsonschema.core.vocab.basic;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
+import jakarta.json.Json;
+import jakarta.json.JsonValue;
+import org.junit.jupiter.api.Test;
+
+class ItemsKeywordTypeTest {
+
+    @Test
+    void should_know_his_name() {
+        final Keyword items = new ItemsKeywordType().createKeyword(JsonValue.EMPTY_JSON_OBJECT);
+
+        assertThat(items.hasName("items"), is(true));
+        assertThat(items.hasName("test"), is(false));
+    }
+
+    @Test
+    void should_be_invalid_if_items_does_not_match_schema() {
+        assertThat(
+            new ItemsKeywordType()
+                .createKeyword(Json.createObjectBuilder().add("type", "number").build())
+                .asAssertion()
+                .isValidFor(Json.createArrayBuilder().add(1).add("invalid").add(2).build()),
+            is(false)
+        );
+    }
+
+    @Test
+    void should_be_valid_if_all_items_match_schema() {
+        assertThat(
+            new ItemsKeywordType()
+                .createKeyword(Json.createObjectBuilder().add("type", "number").build())
+                .asAssertion()
+                .isValidFor(Json.createArrayBuilder().add(1).add(2).build()),
+            is(true)
+        );
+    }
+}