Change of 'nullable' is not detected

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

@@ -12,13 +12,13 @@
 import org.apache.commons.collections4.CollectionUtils;
 import org.openapitools.openapidiff.core.compare.MapKeyDiff;
 import org.openapitools.openapidiff.core.compare.OpenApiDiff;
-import org.openapitools.openapidiff.core.model.ChangedOneOfSchema;
 import org.openapitools.openapidiff.core.model.ChangedSchema;
 import org.openapitools.openapidiff.core.model.DiffContext;
 import org.openapitools.openapidiff.core.model.deferred.DeferredBuilder;
 import org.openapitools.openapidiff.core.model.deferred.DeferredChanged;
 import org.openapitools.openapidiff.core.model.deferred.RealizedChanged;
 import org.openapitools.openapidiff.core.model.deferred.RecursiveSchemaSet;
+import org.openapitools.openapidiff.core.model.schema.ChangedOneOfSchema;
 import org.openapitools.openapidiff.core.utils.RefPointer;
 import org.openapitools.openapidiff.core.utils.RefType;
 

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

@@ -72,6 +72,7 @@ public <V extends Schema<X>, X> DeferredChanged<ChangedSchema> diff(
                 right.getExclusiveMaximum(),
                 context))
         .setMultipleOf(new ChangedMultipleOf(left.getMultipleOf(), right.getMultipleOf()))
+        .setNullable(new ChangedNullable(left.getNullable(), right.getNullable()))
         .setExamples(new ChangedExamples(left.getExamples(), right.getExamples()))
         .setExample(new ChangedExample(left.getExample(), right.getExample()));
     builder

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

@@ -11,7 +11,9 @@
 import org.openapitools.openapidiff.core.model.schema.ChangedEnum;
 import org.openapitools.openapidiff.core.model.schema.ChangedMaxLength;
 import org.openapitools.openapidiff.core.model.schema.ChangedMultipleOf;
+import org.openapitools.openapidiff.core.model.schema.ChangedNullable;
 import org.openapitools.openapidiff.core.model.schema.ChangedNumericRange;
+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.ChangedWriteOnly;
@@ -39,6 +41,7 @@ public class ChangedSchema implements ComposedChanged {
   protected ChangedMaxLength maxLength;
   protected ChangedNumericRange numericRange;
   protected ChangedMultipleOf multipleOf;
+  protected ChangedNullable nullable;
   protected boolean discriminatorPropertyChanged;
   protected ChangedSchema items;
   protected ChangedOneOfSchema oneOfSchema;
@@ -122,6 +125,7 @@ public List<Changed> getChangedElements() {
                       maxLength,
                       numericRange,
                       multipleOf,
+                      nullable,
                       extensions))
               .collect(Collectors.toList());
     }
@@ -285,6 +289,10 @@ public ChangedMultipleOf getMultipleOf() {
     return this.multipleOf;
   }
 
+  public ChangedNullable getNullable() {
+    return this.nullable;
+  }
+
   public boolean isDiscriminatorPropertyChanged() {
     return this.discriminatorPropertyChanged;
   }
@@ -433,6 +441,12 @@ public ChangedSchema setMultipleOf(final ChangedMultipleOf multipleOf) {
     return this;
   }
 
+  public ChangedSchema setNullable(final ChangedNullable nullable) {
+    clearChangedCache();
+    this.nullable = nullable;
+    return this;
+  }
+
   public ChangedSchema setDiscriminatorPropertyChanged(final boolean discriminatorPropertyChanged) {
     clearChangedCache();
     this.discriminatorPropertyChanged = discriminatorPropertyChanged;
@@ -491,6 +505,7 @@ public boolean equals(Object o) {
         && Objects.equals(maxLength, that.maxLength)
         && Objects.equals(numericRange, that.numericRange)
         && Objects.equals(multipleOf, that.multipleOf)
+        && Objects.equals(nullable, that.nullable)
         && Objects.equals(items, that.items)
         && Objects.equals(oneOfSchema, that.oneOfSchema)
         && Objects.equals(addProp, that.addProp)
@@ -522,6 +537,7 @@ public int hashCode() {
         maxLength,
         numericRange,
         multipleOf,
+        nullable,
         discriminatorPropertyChanged,
         items,
         oneOfSchema,
@@ -575,6 +591,8 @@ public java.lang.String toString() {
         + this.getNumericRange()
         + ", multipleOf="
         + this.getMultipleOf()
+        + ", nullable="
+        + this.getNullable()
         + ", discriminatorPropertyChanged="
         + this.isDiscriminatorPropertyChanged()
         + ", items="

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

@@ -0,0 +1,54 @@
+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 ChangedNullable implements Changed {
+
+  private final Boolean left;
+  private final Boolean right;
+
+  public ChangedNullable(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 != rightValue) {
+      return DiffResult.COMPATIBLE;
+    }
+
+    return DiffResult.NO_CHANGES;
+  }
+
+  public Boolean getLeft() {
+    return left;
+  }
+
+  public Boolean getRight() {
+    return right;
+  }
+
+  @Override
+  public String toString() {
+    return "ChangedNullable [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/main/java/org/openapitools/openapidiff/core/model/ChangedOneOfSchema.java → core/src/main/java/org/openapitools/openapidiff/core/model/schema/ChangedOneOfSchema.java

@@ -1,4 +1,4 @@
-package org.openapitools.openapidiff.core.model;
+package org.openapitools.openapidiff.core.model.schema;
 
 import static org.openapitools.openapidiff.core.model.BackwardIncompatibleProp.REQUEST_ONEOF_DECREASED;
 import static org.openapitools.openapidiff.core.model.BackwardIncompatibleProp.RESPONSE_ONEOF_INCREASED;
@@ -8,6 +8,11 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import org.openapitools.openapidiff.core.model.Changed;
+import org.openapitools.openapidiff.core.model.ChangedSchema;
+import org.openapitools.openapidiff.core.model.ComposedChanged;
+import org.openapitools.openapidiff.core.model.DiffContext;
+import org.openapitools.openapidiff.core.model.DiffResult;
 
 public class ChangedOneOfSchema implements ComposedChanged {
   private final Map<String, String> oldMapping;

core/src/main/java/org/openapitools/openapidiff/core/output/MarkdownRender.java

@@ -20,6 +20,7 @@
 import org.apache.commons.lang3.StringUtils;
 import org.openapitools.openapidiff.core.exception.RendererException;
 import org.openapitools.openapidiff.core.model.*;
+import org.openapitools.openapidiff.core.model.schema.ChangedOneOfSchema;
 import org.openapitools.openapidiff.core.utils.RefPointer;
 import org.openapitools.openapidiff.core.utils.RefType;
 import org.slf4j.Logger;

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

@@ -134,4 +134,35 @@ public void changeMultipleOfHandling() {
     assertThat(props.get("field4").getMultipleOf().getLeft()).isEqualTo(BigDecimal.valueOf(10));
     assertThat(props.get("field4").getMultipleOf().getRight()).isNull();
   }
+
+  @Test // issue #482
+  public void changeNullabeHandling() {
+    ChangedOpenApi changedOpenApi =
+        OpenApiCompare.fromLocations(
+            "schemaDiff/schema-nullable-diff-1.yaml", "schemaDiff/schema-nullable-diff-2.yaml");
+    ChangedSchema changedSchema =
+        getRequestBodyChangedSchema(changedOpenApi, POST, "/schema/nullable", "application/json");
+
+    assertThat(changedSchema).isNotNull();
+    Map<String, ChangedSchema> props = changedSchema.getChangedProperties();
+    assertThat(props).isNotEmpty();
+
+    // Check no changes in nullable
+    assertThat(props.get("field0")).isNull();
+
+    // Check changes in nullable
+    assertThat(props.get("field1").getNullable().isCompatible()).isTrue();
+    assertThat(props.get("field1").getNullable().getLeft()).isTrue();
+    assertThat(props.get("field1").getNullable().getRight()).isFalse();
+
+    // Check deletion of nullable
+    assertThat(props.get("field2").getNullable().isCompatible()).isTrue();
+    assertThat(props.get("field2").getNullable().getLeft()).isTrue();
+    assertThat(props.get("field2").getNullable().getRight()).isNull();
+
+    // Check addition of nullable
+    assertThat(props.get("field3").getNullable().isCompatible()).isTrue();
+    assertThat(props.get("field3").getNullable().getLeft()).isNull();
+    assertThat(props.get("field3").getNullable().getRight()).isTrue();
+  }
 }

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

@@ -0,0 +1,28 @@
+openapi: 3.0.1
+info:
+  description: Schema diff nullable
+  title: schema diff nullable
+  version: 1.0.0
+paths:
+  /schema/nullable:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/TestDTO'
+components:
+  schemas:
+    TestDTO:
+      type: object
+      properties:
+        field0:
+          type: integer
+        field1:
+          type: integer
+          nullable: true
+        field2:
+          type: integer
+          nullable: true
+        field3:
+          type: integer

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

@@ -0,0 +1,28 @@
+openapi: 3.0.1
+info:
+  description: Schema diff nullable
+  title: schema diff nullable
+  version: 1.0.0
+paths:
+  /schema/nullable:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/TestDTO'
+components:
+  schemas:
+    TestDTO:
+      type: object
+      properties:
+        field0:
+          type: integer
+        field1:
+          type: integer
+          nullable: false
+        field2:
+          type: integer
+        field3:
+          type: integer
+          nullable: true