Add support for 'uniqueItems' schema diff detection

core/src/main/java/org/openapitools/openapidiff/core/compare/schemadiffresult/SchemaDiffResult.java

@@ -75,6 +75,7 @@ public <V extends Schema<X>, X> DeferredChanged<ChangedSchema> diff(
                 context))
         .setMultipleOf(new ChangedMultipleOf(left.getMultipleOf(), right.getMultipleOf()))
         .setNullable(new ChangedNullable(left.getNullable(), right.getNullable()))
+        .setUniqueItems(new ChangedUniqueItems(left.getUniqueItems(), right.getUniqueItems()))
         .setExamples(new ChangedExamples(left.getExamples(), right.getExamples()))
         .setExample(new ChangedExample(left.getExample(), right.getExample()))
         .setMaxItems(new ChangedMaxItems(left.getMaxItems(), right.getMaxItems(), context))

core/src/main/java/org/openapitools/openapidiff/core/model/ChangedSchema.java

@@ -20,6 +20,7 @@
 import org.openapitools.openapidiff.core.model.schema.ChangedOneOfSchema;
 import org.openapitools.openapidiff.core.model.schema.ChangedReadOnly;
 import org.openapitools.openapidiff.core.model.schema.ChangedRequired;
+import org.openapitools.openapidiff.core.model.schema.ChangedUniqueItems;
 import org.openapitools.openapidiff.core.model.schema.ChangedWriteOnly;
 
 public class ChangedSchema implements ComposedChanged {
@@ -50,6 +51,7 @@ public class ChangedSchema implements ComposedChanged {
   protected ChangedMaxProperties maxProperties;
   protected ChangedMinProperties minProperties;
   protected ChangedNullable nullable;
+  protected ChangedUniqueItems uniqueItems;
   protected boolean discriminatorPropertyChanged;
   protected ChangedSchema items;
   protected ChangedOneOfSchema oneOfSchema;
@@ -138,6 +140,7 @@ public List<Changed> getChangedElements() {
                       maxProperties,
                       minProperties,
                       nullable,
+                      uniqueItems,
                       extensions))
               .collect(Collectors.toList());
     }
@@ -313,6 +316,10 @@ public ChangedNullable getNullable() {
     return this.nullable;
   }
 
+  public ChangedUniqueItems getUniqueItems() {
+    return uniqueItems;
+  }
+
   public boolean isDiscriminatorPropertyChanged() {
     return this.discriminatorPropertyChanged;
   }
@@ -487,6 +494,12 @@ public ChangedSchema setNullable(final ChangedNullable nullable) {
     return this;
   }
 
+  public ChangedSchema setUniqueItems(ChangedUniqueItems uniqueItems) {
+    clearChangedCache();
+    this.uniqueItems = uniqueItems;
+    return this;
+  }
+
   public ChangedSchema setDiscriminatorPropertyChanged(final boolean discriminatorPropertyChanged) {
     clearChangedCache();
     this.discriminatorPropertyChanged = discriminatorPropertyChanged;
@@ -560,6 +573,7 @@ public boolean equals(Object o) {
         && Objects.equals(maxItems, that.maxItems)
         && Objects.equals(minItems, that.minItems)
         && Objects.equals(nullable, that.nullable)
+        && Objects.equals(uniqueItems, that.uniqueItems)
         && Objects.equals(items, that.items)
         && Objects.equals(oneOfSchema, that.oneOfSchema)
         && Objects.equals(addProp, that.addProp)
@@ -596,6 +610,7 @@ public int hashCode() {
         maxItems,
         minItems,
         nullable,
+        uniqueItems,
         discriminatorPropertyChanged,
         items,
         oneOfSchema,
@@ -657,6 +672,8 @@ public java.lang.String toString() {
         + this.getMinItems()
         + ", nullable="
         + this.getNullable()
+        + ", uniqueItems="
+        + this.getUniqueItems()
         + ", discriminatorPropertyChanged="
         + this.isDiscriminatorPropertyChanged()
         + ", items="

core/src/main/java/org/openapitools/openapidiff/core/model/schema/ChangedUniqueItems.java

@@ -0,0 +1,58 @@
+package org.openapitools.openapidiff.core.model.schema;
+
+import java.util.Objects;
+import org.openapitools.openapidiff.core.model.Changed;
+import org.openapitools.openapidiff.core.model.DiffResult;
+
+public class ChangedUniqueItems implements Changed {
+
+  private final Boolean left;
+  private final Boolean right;
+
+  public ChangedUniqueItems(Boolean leftNullable, Boolean rightNullable) {
+    this.left = leftNullable;
+    this.right = rightNullable;
+  }
+
+  @Override
+  public DiffResult isChanged() {
+    boolean leftValue = left != null && left;
+    boolean rightValue = right != null && right;
+
+    if (leftValue == false && rightValue == true) {
+      return DiffResult.INCOMPATIBLE;
+    }
+
+    if (leftValue == true && rightValue == false) {
+      return DiffResult.COMPATIBLE;
+    }
+
+    return DiffResult.NO_CHANGES;
+  }
+
+  public Boolean getLeft() {
+    return left;
+  }
+
+  public Boolean getRight() {
+    return right;
+  }
+
+  @Override
+  public String toString() {
+    return "ChangedUniqueItems [left=" + left + ", right=" + right + "]";
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    ChangedNullable that = (ChangedNullable) o;
+    return Objects.equals(left, that.getLeft()) && Objects.equals(right, that.getRight());
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(left, right);
+  }
+}

core/src/test/java/org/openapitools/openapidiff/core/SchemaDiffTest.java

@@ -171,7 +171,7 @@ public void changeMinMaxItemsHandling() {
   }
 
   @Test // issue #482
-  public void changeNullabeHandling() {
+  public void changeNullableHandling() {
     ChangedOpenApi changedOpenApi =
         OpenApiCompare.fromLocations(
             "schemaDiff/schema-nullable-diff-1.yaml", "schemaDiff/schema-nullable-diff-2.yaml");
@@ -201,6 +201,44 @@ public void changeNullabeHandling() {
     assertThat(props.get("field3").getNullable().getRight()).isTrue();
   }
 
+  @Test // issue #478
+  public void changeUniqueItemsHandling() {
+    ChangedOpenApi changedOpenApi =
+        OpenApiCompare.fromLocations(
+            "schemaDiff/schema-uniqueItems-diff-1.yaml",
+            "schemaDiff/schema-uniqueItems-diff-2.yaml");
+    ChangedSchema changedSchema =
+        getRequestBodyChangedSchema(
+            changedOpenApi, POST, "/schema/uniqueItems", "application/json");
+
+    assertThat(changedSchema).isNotNull();
+    Map<String, ChangedSchema> props = changedSchema.getChangedProperties();
+    assertThat(props).isNotEmpty();
+
+    // Check no changes in uniqueItems
+    assertThat(props.get("field0")).isNull();
+
+    // Check changes true -> false
+    assertThat(props.get("field1").getUniqueItems().isCompatible()).isTrue();
+    assertThat(props.get("field1").getUniqueItems().getLeft()).isTrue();
+    assertThat(props.get("field1").getUniqueItems().getRight()).isFalse();
+
+    // Check changes false -> true
+    assertThat(props.get("field2").getUniqueItems().isIncompatible()).isTrue();
+    assertThat(props.get("field2").getUniqueItems().getLeft()).isFalse();
+    assertThat(props.get("field2").getUniqueItems().getRight()).isTrue();
+
+    // Check deletion of uniqueItems
+    assertThat(props.get("field3").getUniqueItems().isCompatible()).isTrue();
+    assertThat(props.get("field3").getUniqueItems().getLeft()).isTrue();
+    assertThat(props.get("field3").getUniqueItems().getRight()).isNull();
+
+    // Check addition of uniqueItems
+    assertThat(props.get("field4").getUniqueItems().isIncompatible()).isTrue();
+    assertThat(props.get("field4").getUniqueItems().getLeft()).isNull();
+    assertThat(props.get("field4").getUniqueItems().getRight()).isTrue();
+  }
+
   @Test // issue #479
   public void changeMinMaxPropertiesHandling() {
     ChangedOpenApi changedOpenApi =

core/src/test/resources/schemaDiff/schema-uniqueItems-diff-1.yaml

@@ -0,0 +1,31 @@
+openapi: 3.0.1
+info:
+  description: Schema diff uniqueItems
+  title: schema diff uniqueItems
+  version: 1.0.0
+paths:
+  /schema/uniqueItems:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/TestDTO'
+components:
+  schemas:
+    TestDTO:
+      type: object
+      properties:
+        field0:
+          type: integer
+        field1:
+          type: integer
+          uniqueItems: true
+        field2:
+          type: integer
+          uniqueItems: false
+        field3:
+          type: integer
+          uniqueItems: true
+        field4:
+          type: integer

core/src/test/resources/schemaDiff/schema-uniqueItems-diff-2.yaml

@@ -0,0 +1,31 @@
+openapi: 3.0.1
+info:
+  description: Schema diff uniqueItems
+  title: schema diff uniqueItems
+  version: 1.0.0
+paths:
+  /schema/uniqueItems:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/TestDTO'
+components:
+  schemas:
+    TestDTO:
+      type: object
+      properties:
+        field0:
+          type: integer
+        field1:
+          type: integer
+          uniqueItems: false
+        field2:
+          type: integer
+          uniqueItems: true
+        field3:
+          type: integer
+        field4:
+          type: integer
+          uniqueItems: true