sebastian-toepfer · sebastian-toepfer · Oct 5, 2023 · Sep 26, 2023 · Oct 5, 2023
diff --git a/api/src/main/java/io/github/sebastiantoepfer/jsonschema/JsonSchema.java b/api/src/main/java/io/github/sebastiantoepfer/jsonschema/JsonSchema.java
@@ -23,8 +23,12 @@
  */
 package io.github.sebastiantoepfer.jsonschema;
 
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
 import jakarta.json.JsonValue;
+import java.util.Optional;
 
 public interface JsonSchema extends JsonValue {
     public Validator validator();
+
+    Optional<Keyword> keywordByName(String name);
 }
diff --git a/api/src/test/java/io/github/sebastiantoepfer/jsonschema/FakeJsonSchemaFactory.java b/api/src/test/java/io/github/sebastiantoepfer/jsonschema/FakeJsonSchemaFactory.java
@@ -23,8 +23,10 @@
  */
 package io.github.sebastiantoepfer.jsonschema;
 
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
 import io.github.sebastiantoepfer.jsonschema.spi.JsonSchemaFactory;
 import jakarta.json.JsonValue;
+import java.util.Optional;
 
 public final class FakeJsonSchemaFactory implements JsonSchemaFactory {
 
@@ -40,6 +42,11 @@ public Validator validator() {
             public JsonValue.ValueType getValueType() {
                 throw new UnsupportedOperationException("Not supported yet.");
             }
+
+            @Override
+            public Optional<Keyword> keywordByName(String name) {
+                throw new UnsupportedOperationException("Not supported yet.");
+            }
         };
     }
 }
diff --git a/core/pom.xml b/core/pom.xml
@@ -111,6 +111,7 @@
                                         <inculde>**/tests/draft2020-12/maximum.json</inculde>
                                         <inculde>**/tests/draft2020-12/exclusiveMaximum.json</inculde>
                                         <inculde>**/tests/draft2020-12/multipleOf.json</inculde>
+                                        <inculde>**/tests/draft2020-12/prefixItems.json</inculde>
                                         <!-- more than items keyword needed :(
                                         <inculde>**/tests/draft2020-12/items.json</inculde>
                                         -->

diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/DefaultJsonSchema.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/DefaultJsonSchema.java
@@ -40,9 +40,9 @@
 import jakarta.json.JsonValue;
 import java.util.Collection;
 import java.util.List;
-import java.util.Map.Entry;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 final class DefaultJsonSchema extends AbstractJsonValueSchema {
 
@@ -55,16 +55,19 @@ public DefaultJsonSchema(final JsonObject value) {
 
     @Override
     public Validator validator() {
-        return asJsonObject()
-            .entrySet()
-            .stream()
+        return keywords()
             .map(this::asContraint)
             .flatMap(Optional::stream)
             .collect(
                 collectingAndThen(toList(), constraints -> new DefaultValidator(new AllOfConstraint<>(constraints)))
             );
     }
 
+    @Override
+    public Optional<Keyword> keywordByName(final String name) {
+        return keywords().filter(k -> k.hasName(name)).findFirst();
+    }
+
     private Collection<VocabularyDefinition> vocabulary() {
         return new KeywordSearch(new VocabularyKeywordType())
             .searchForKeywordIn(this)
@@ -75,8 +78,11 @@ private Collection<VocabularyDefinition> vocabulary() {
             .toList();
     }
 
-    private Optional<Constraint<JsonValue>> asContraint(final Entry<String, JsonValue> property) {
-        final Keyword keyword = keywords.createKeywordFor(this, property);
+    private Stream<Keyword> keywords() {
+        return asJsonObject().entrySet().stream().map(property -> keywords.createKeywordFor(this, property));
+    }
+
+    private Optional<Constraint<JsonValue>> asContraint(final Keyword keyword) {
         final Constraint<JsonValue> result;
         if (keyword.hasCategory(Keyword.KeywordCategory.ASSERTION)) {
             result = new AssertionConstraint(keyword.asAssertion());

diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/EmptyJsonSchema.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/EmptyJsonSchema.java
@@ -25,7 +25,9 @@
 
 import io.github.sebastiantoepfer.jsonschema.Validator;
 import io.github.sebastiantoepfer.jsonschema.core.constraint.NoConstraint;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
 import jakarta.json.JsonValue;
+import java.util.Optional;
 
 final class EmptyJsonSchema extends AbstractJsonValueSchema {
 
@@ -37,4 +39,9 @@ public EmptyJsonSchema() {
     public Validator validator() {
         return new DefaultValidator(new NoConstraint<>());
     }
+
+    @Override
+    public Optional<Keyword> keywordByName(final String name) {
+        return Optional.empty();
+    }
 }
diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/FalseJsonSchema.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/FalseJsonSchema.java
@@ -25,7 +25,9 @@
 
 import io.github.sebastiantoepfer.jsonschema.Validator;
 import io.github.sebastiantoepfer.jsonschema.core.constraint.UnfulfillableConstraint;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
 import jakarta.json.JsonValue;
+import java.util.Optional;
 
 final class FalseJsonSchema extends AbstractJsonValueSchema {
 
@@ -37,4 +39,9 @@ public FalseJsonSchema() {
     public Validator validator() {
         return new DefaultValidator(new UnfulfillableConstraint<>());
     }
+
+    @Override
+    public Optional<Keyword> keywordByName(final String name) {
+        return Optional.empty();
+    }
 }
diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/TrueJsonSchema.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/TrueJsonSchema.java
@@ -25,7 +25,9 @@
 
 import io.github.sebastiantoepfer.jsonschema.Validator;
 import io.github.sebastiantoepfer.jsonschema.core.constraint.NoConstraint;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
 import jakarta.json.JsonValue;
+import java.util.Optional;
 
 final class TrueJsonSchema extends AbstractJsonValueSchema {
 
@@ -37,4 +39,9 @@ public TrueJsonSchema() {
     public Validator validator() {
         return new DefaultValidator(new NoConstraint<>());
     }
+
+    @Override
+    public Optional<Keyword> keywordByName(final String name) {
+        return Optional.empty();
+    }
 }
diff --git a/...ava/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ApplicatorVocabulary.java b/...ava/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ApplicatorVocabulary.java
@@ -37,6 +37,7 @@ public ApplicatorVocabulary() {
         this.vocab =
             new DefaultVocabulary(
                 URI.create("https://json-schema.org/draft/2020-12/vocab/applicator"),
+                new PrefixItemsKeywordType(),
                 new ItemsKeywordType()
             );
     }

diff --git a/...in/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ItemsKeywordType.java b/...in/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ItemsKeywordType.java
@@ -33,10 +33,12 @@
 import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
 import io.github.sebastiantoepfer.jsonschema.keyword.KeywordType;
 import jakarta.json.JsonArray;
+import jakarta.json.JsonNumber;
 import jakarta.json.JsonValue;
 import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
 
 final class ItemsKeywordType implements KeywordType {
 
@@ -75,6 +77,11 @@ public ValueType getValueType() {
             return schema.getValueType();
         }
 
+        @Override
+        public Optional<Keyword> keywordByName(final String name) {
+            return schema.keywordByName(name);
+        }
+
         @Override
         public boolean hasName(final String name) {
             return Objects.equals(name(), name);
@@ -87,7 +94,17 @@ public Collection<KeywordCategory> categories() {
 
         @Override
         public JsonValue value() {
-            return JsonValue.TRUE;
+            final JsonValue result;
+            if (appliesToAny()) {
+                result = JsonValue.TRUE;
+            } else {
+                result = JsonValue.FALSE;
+            }
+            return result;
+        }
+
+        private boolean appliesToAny() {
+            return startIndex() < 0;
         }
 
         @Override
@@ -97,7 +114,18 @@ public boolean applyTo(final JsonValue instance) {
 
         private boolean matchesSchema(final JsonArray items) {
             final Validator itemValidator = validator();
-            return items.stream().map(itemValidator::validate).allMatch(Collection::isEmpty);
+            return items.stream().skip(startIndex() + 1).map(itemValidator::validate).allMatch(Collection::isEmpty);
+        }
+
+        private long startIndex() {
+            return owner()
+                .keywordByName("prefixItems")
+                .map(Keyword::asAnnotation)
+                .map(Annotation::value)
+                .filter(InstanceType.INTEGER::isInstance)
+                .map(JsonNumber.class::cast)
+                .map(JsonNumber::longValue)
+                .orElse(-1L);
         }
     }
 }
diff --git a/...a/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/PrefixItemsKeywordType.java b/...a/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/PrefixItemsKeywordType.java
@@ -0,0 +1,99 @@
+/*
+ * 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.applicator;
+
+import io.github.sebastiantoepfer.jsonschema.InstanceType;
+import io.github.sebastiantoepfer.jsonschema.JsonSchema;
+import io.github.sebastiantoepfer.jsonschema.JsonSchemas;
+import io.github.sebastiantoepfer.jsonschema.keyword.Annotation;
+import io.github.sebastiantoepfer.jsonschema.keyword.Applicator;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
+import io.github.sebastiantoepfer.jsonschema.keyword.KeywordType;
+import jakarta.json.Json;
+import jakarta.json.JsonArray;
+import jakarta.json.JsonValue;
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * https://json-schema.org/draft/2020-12/json-schema-core#section-10.3.1.1
+ * https://www.learnjsonschema.com/2020-12/applicator/prefixitems/
+ */
+final class PrefixItemsKeywordType implements KeywordType {
+
+    @Override
+    public String name() {
+        return "prefixItems";
+    }
+
+    @Override
+    public Keyword createKeyword(final JsonSchema schema, final JsonValue value) {
+        if (InstanceType.ARRAY.isInstance(value)) {
+            return new PrefixItemsKeyword(value.asJsonArray());
+        } else {
+            throw new IllegalArgumentException("must be a non empty array!");
+        }
+    }
+
+    private class PrefixItemsKeyword implements Annotation, Applicator {
+
+        private final List<JsonSchema> schemas;
+
+        public PrefixItemsKeyword(final JsonArray schemas) {
+            this.schemas = schemas.stream().map(JsonSchemas::load).toList();
+        }
+
+        @Override
+        public Collection<KeywordCategory> categories() {
+            return List.of(KeywordCategory.ANNOTATION, KeywordCategory.APPLICATOR);
+        }
+
+        @Override
+        public boolean hasName(final String name) {
+            return Objects.equals(name(), name);
+        }
+
+        @Override
+        public JsonValue value() {
+            return Json.createValue(schemas.size() - 1);
+        }
+
+        @Override
+        public boolean applyTo(final JsonValue instance) {
+            return !InstanceType.ARRAY.isInstance(instance) || matchesSchemas(instance.asJsonArray());
+        }
+
+        private boolean matchesSchemas(final JsonArray instance) {
+            boolean result = true;
+            for (int i = 0; i < Math.min(schemas.size(), instance.size()); i++) {
+                result &= schemas.get(i).validator().validate(instance.get(i)).isEmpty();
+                if (!result) {
+                    break;
+                }
+            }
+            return result;
+        }
+    }
+}
diff --git a/...src/test/java/io/github/sebastiantoepfer/jsonschema/core/AbstractJsonValueSchemaTest.java b/...src/test/java/io/github/sebastiantoepfer/jsonschema/core/AbstractJsonValueSchemaTest.java
@@ -28,9 +28,11 @@
 import static org.hamcrest.Matchers.is;
 
 import io.github.sebastiantoepfer.jsonschema.Validator;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
 import jakarta.json.JsonArray;
 import jakarta.json.JsonObject;
 import jakarta.json.JsonValue;
+import java.util.Optional;
 import org.junit.jupiter.api.Test;
 
 class AbstractJsonValueSchemaTest {
@@ -65,5 +67,10 @@ public MyJsonValueSchema(JsonValue value) {
         public Validator validator() {
             throw new UnsupportedOperationException("Not supported yet.");
         }
+
+        @Override
+        public Optional<Keyword> keywordByName(final String name) {
+            return Optional.empty();
+        }
     }
 }
diff --git a/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/DefaultJsonSchemaTest.java b/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/DefaultJsonSchemaTest.java
@@ -23,6 +23,8 @@
  */
 package io.github.sebastiantoepfer.jsonschema.core;
 
+import static com.github.npathai.hamcrestopt.OptionalMatchers.isEmpty;
+import static com.github.npathai.hamcrestopt.OptionalMatchers.isPresent;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.is;
@@ -76,4 +78,38 @@ void should_not_be_loadable_without_mandantory_core_vocabulary() {
 
         Assertions.assertThrows(Exception.class, () -> new DefaultJsonSchema(invalidSchema));
     }
+
+    @Test
+    void should_find_keyword_by_name() {
+        assertThat(
+            new DefaultJsonSchema(
+                Json
+                    .createObjectBuilder()
+                    .add(
+                        "$vocabulary",
+                        Json.createObjectBuilder().add("https://json-schema.org/draft/2020-12/vocab/core", true)
+                    )
+                    .build()
+            )
+                .keywordByName("$vocabulary"),
+            isPresent()
+        );
+    }
+
+    @Test
+    void should_return_empty_for_non_existing_keyword() {
+        assertThat(
+            new DefaultJsonSchema(
+                Json
+                    .createObjectBuilder()
+                    .add(
+                        "$vocabulary",
+                        Json.createObjectBuilder().add("https://json-schema.org/draft/2020-12/vocab/core", true)
+                    )
+                    .build()
+            )
+                .keywordByName("type"),
+            isEmpty()
+        );
+    }
 }