fix: additional properties external references not processed. Fixes #2218

Author: ewaostrowska

modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/processors/ExternalRefProcessor.java

@@ -169,7 +169,7 @@ public String processRefToExternalSchema(String $ref, RefFormat refFormat) {
                 } else if (additionalProperty instanceof ArraySchema) {
                     ArraySchema arrayProp = (ArraySchema) additionalProperty;
                     if (arrayProp.getItems() != null && arrayProp.getItems().get$ref() != null &&
-                            StringUtils.isNotBlank(arrayProp.get$ref())) {
+                            StringUtils.isNotBlank(arrayProp.getItems().get$ref())) {
                         processRefSchema(arrayProp.getItems(), file);
                     }
                 } else if (additionalProperty.getAdditionalProperties() != null && additionalProperty.getAdditionalProperties() instanceof Schema) {

modules/swagger-parser-v3/src/test/java/io/swagger/v3/parser/processors/ExternalRefProcessorTest.java

@@ -29,6 +29,7 @@
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertNotNull;
 
 
 public class ExternalRefProcessorTest {
@@ -254,4 +255,22 @@ public void testHandleInlineRefsInComposedSchemas() {
         assertThat(anyOfInlineProduct.get$ref(), is("#/components/schemas/Product"));
     }
 
+    @Test
+    public void testAdditionalPropertiesReferenceResolution() {
+        String inputSpec = "src/test/resources/issue-2218/main.yaml";
+        List<AuthorizationValue> authorizationValues = null;
+
+        ParseOptions options = new ParseOptions();
+        options.setResolve(true);
+        SwaggerParseResult result = new OpenAPIV3Parser().readLocation(inputSpec, authorizationValues, options);
+
+        OpenAPI openAPI = result.getOpenAPI();
+
+        Map<String, Schema> schemas = openAPI.getComponents().getSchemas();
+        assertNotNull(schemas, "Schemas should not be null");
+        Assert.assertTrue(schemas.containsKey("FlagsOfFlags"), "FlagsOfFlags schema should be resolved and available in components");
+        Assert.assertTrue(schemas.containsKey("Flags"), "Flags schema should be resolved and available in components");
+        Assert.assertTrue(schemas.containsKey("Flag"), "Flag schema should be resolved and available in components");
+    }
+
 }

modules/swagger-parser-v3/src/test/resources/issue-2218/main.yaml

@@ -0,0 +1,16 @@
+openapi: 3.0.3
+info:
+  description: A service with remote models
+  version: 1.0.o
+  title: A service
+paths:
+  /foo:
+    get:
+      description: Get Flag of flags
+      responses:
+        '200':
+          description: ok
+          content:
+            application/json:
+              schema:
+                $ref: './model.yaml#/components/schemas/FlagsOfFlags'

modules/swagger-parser-v3/src/test/resources/issue-2218/model.yaml

@@ -0,0 +1,28 @@
+openapi: 3.0.3
+info:
+  description: Description
+  version: 1.0.0
+  title: A title
+paths: {}
+components:
+  schemas:
+    Flag:
+      type: object
+      description: Active flag
+      properties:
+        isActive:
+          type: boolean
+    Flags:
+      type: object
+      description: Map of flags
+      additionalProperties:
+        type: array
+        items:
+          $ref: '#/components/schemas/Flag'
+    FlagsOfFlags:
+      type: object
+      description: Flag of flag configuration
+      additionalProperties:
+        type: array
+        items:
+          $ref: '#/components/schemas/Flags'