add support for oneOf keyword

core/pom.xml

@@ -122,6 +122,7 @@
                     <include>**/tests/draft2020-12/allOf.json</include>
                     -->
                     <include>**/tests/draft2020-12/anyOf.json</include>
+                    <include>**/tests/draft2020-12/oneOf.json</include>
                     <include>**/tests/draft2020-12/boolean_schema.json</include>
                     <include>**/tests/draft2020-12/const.json</include>
                     <include>**/tests/draft2020-12/contains.json</include>

core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ApplicatorVocabulary.java

@@ -50,6 +50,7 @@ public ApplicatorVocabulary() {
             URI.create("https://json-schema.org/draft/2020-12/vocab/applicator"),
             new SchemaArrayKeywordType(AllOfKeyword.NAME, AllOfKeyword::new),
             new SchemaArrayKeywordType(AnyOfKeyword.NAME, AnyOfKeyword::new),
+            new SchemaArrayKeywordType(OneOfKeyword.NAME, OneOfKeyword::new),
             new NamedJsonSchemaKeywordType(PropertiesKeyword.NAME, PropertiesKeyword::new),
             new SubSchemaKeywordType(AdditionalPropertiesKeyword.NAME, AdditionalPropertiesKeyword::new),
             new NamedJsonSchemaKeywordType(PatternPropertiesKeyword.NAME, PatternPropertiesKeyword::new),

core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeyword.java

@@ -0,0 +1,70 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2024 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.ddd.common.Media;
+import io.github.sebastiantoepfer.jsonschema.JsonSchema;
+import io.github.sebastiantoepfer.jsonschema.keyword.Applicator;
+import jakarta.json.JsonValue;
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * <b>oneOf</b> : <i>Array<Schema></i><br/>
+ * An instance validates successfully against this keyword if it validates successfully against exactly one schema
+ * defined by this keyword’s value.<br/>
+ * <br/>
+ * <b>kind</b>
+ * <ul>
+ * <li>Applicator</li>
+ * </ul>
+ *
+ * source: https://www.learnjsonschema.com/2020-12/applicator/oneof/
+ * spec: https://json-schema.org/draft/2020-12/json-schema-core.html#section-10.2.1.3
+ */
+final class OneOfKeyword implements Applicator {
+
+    static final String NAME = "oneOf";
+    private final Collection<JsonSchema> schemas;
+
+    public OneOfKeyword(final Collection<JsonSchema> schemas) {
+        this.schemas = List.copyOf(schemas);
+    }
+
+    @Override
+    public boolean applyTo(final JsonValue instance) {
+        return schemas.stream().map(JsonSchema::validator).filter(v -> v.isValid(instance)).limit(2).count() == 1;
+    }
+
+    @Override
+    public boolean hasName(final String name) {
+        return Objects.equals(NAME, name);
+    }
+
+    @Override
+    public <T extends Media<T>> T printOn(final T media) {
+        return media.withValue(NAME, schemas);
+    }
+}

core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeywordTest.java

@@ -0,0 +1,197 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2024 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 static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.hasEntry;
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.hasKey;
+import static org.hamcrest.Matchers.is;
+
+import io.github.sebastiantoepfer.ddd.media.core.HashMapMedia;
+import io.github.sebastiantoepfer.jsonschema.core.DefaultJsonSchemaFactory;
+import io.github.sebastiantoepfer.jsonschema.core.keyword.type.SchemaArrayKeywordType;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
+import jakarta.json.Json;
+import jakarta.json.JsonObject;
+import jakarta.json.JsonValue;
+import org.hamcrest.Matcher;
+import org.junit.jupiter.api.Test;
+
+class OneOfKeywordTest {
+
+    @Test
+    void should_know_his_name() {
+        final Keyword items = createKeywordFrom(
+            Json.createObjectBuilder().add("oneOf", Json.createArrayBuilder().add(JsonValue.TRUE)).build()
+        );
+
+        assertThat(items.hasName("oneOf"), is(true));
+        assertThat(items.hasName("test"), is(false));
+    }
+
+    @Test
+    void should_be_printable() {
+        assertThat(
+            createKeywordFrom(
+                Json.createObjectBuilder()
+                    .add(
+                        "oneOf",
+                        Json.createArrayBuilder()
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("foo", Json.createObjectBuilder().add("type", "string"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("foo"))
+                            )
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("bar", Json.createObjectBuilder().add("type", "number"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("bar"))
+                            )
+                    )
+                    .build()
+            ).printOn(new HashMapMedia()),
+            (Matcher) hasEntry(is("oneOf"), hasItem((hasKey("properties"))))
+        );
+    }
+
+    @Test
+    void should_be_valid_if_exactly_one_schema_applies() {
+        assertThat(
+            createKeywordFrom(
+                Json.createObjectBuilder()
+                    .add(
+                        "oneOf",
+                        Json.createArrayBuilder()
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("foo", Json.createObjectBuilder().add("type", "string"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("foo"))
+                            )
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("bar", Json.createObjectBuilder().add("type", "number"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("bar"))
+                            )
+                    )
+                    .build()
+            )
+                .asApplicator()
+                .applyTo(Json.createObjectBuilder().add("foo", "foo").build()),
+            is(true)
+        );
+    }
+
+    @Test
+    void should_be_invalid_if_none_schema_not_apply() {
+        assertThat(
+            createKeywordFrom(
+                Json.createObjectBuilder()
+                    .add(
+                        "oneOf",
+                        Json.createArrayBuilder()
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("foo", Json.createObjectBuilder().add("type", "string"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("foo"))
+                            )
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("bar", Json.createObjectBuilder().add("type", "number"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("bar"))
+                            )
+                    )
+                    .build()
+            )
+                .asApplicator()
+                .applyTo(Json.createObjectBuilder().add("foo", 3).add("bar", "bar").build()),
+            is(false)
+        );
+    }
+
+    @Test
+    void should_be_invalid_if_more_than_one_schema_apply() {
+        assertThat(
+            createKeywordFrom(
+                Json.createObjectBuilder()
+                    .add(
+                        "oneOf",
+                        Json.createArrayBuilder()
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("foo", Json.createObjectBuilder().add("type", "string"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("foo"))
+                            )
+                            .add(
+                                Json.createObjectBuilder()
+                                    .add(
+                                        "properties",
+                                        Json.createObjectBuilder()
+                                            .add("bar", Json.createObjectBuilder().add("type", "number"))
+                                    )
+                                    .add("required", Json.createArrayBuilder().add("bar"))
+                            )
+                    )
+                    .build()
+            )
+                .asApplicator()
+                .applyTo(Json.createObjectBuilder().add("foo", "foo").add("bar", 33).build()),
+            is(false)
+        );
+    }
+
+    private static Keyword createKeywordFrom(final JsonObject json) {
+        return new SchemaArrayKeywordType("oneOf", OneOfKeyword::new).createKeyword(
+            new DefaultJsonSchemaFactory().create(json)
+        );
+    }
+}