Include discriminator mapped schemas when filtering

Author: eak24

modules/swagger-core/src/main/java/io/swagger/v3/core/filter/SpecFilter.java

@@ -291,6 +291,12 @@ private void addSchemaRef(Schema schema, Set<String> referencedDefinitions) {
             referencedDefinitions.add(schema.get$ref());
             return;
         }
+        if (schema.getDiscriminator() != null) {
+            for (Map.Entry<String, String> mapping: schema.getDiscriminator().getMapping().entrySet()) {
+                referencedDefinitions.add(mapping.getValue());
+            }
+            return;
+        }
 
         if (schema.getProperties() != null) {
             for (Object propName : schema.getProperties().keySet()) {

modules/swagger-core/src/test/java/io/swagger/v3/core/filter/SpecFilterTest.java

@@ -255,6 +255,20 @@ public void shouldRemoveBrokenNestedRefs() throws IOException {
         assertNotNull(filtered.getComponents().getSchemas().get("Category"));
         assertNotNull(filtered.getComponents().getSchemas().get("Pet"));
         assertNotNull(filtered.getComponents().getSchemas().get("Foo"));
+        assertNotNull(filtered.getComponents().getSchemas().get("allOfChild"));
+        assertNotNull(filtered.getComponents().getSchemas().get("anyOfChild"));
+        assertNotNull(filtered.getComponents().getSchemas().get("oneOfChild"));
+        assertNotNull(filtered.getComponents().getSchemas().get("allOfparentA"));
+        assertNotNull(filtered.getComponents().getSchemas().get("allOfparentB"));
+        assertNotNull(filtered.getComponents().getSchemas().get("anyOfparentA"));
+        assertNotNull(filtered.getComponents().getSchemas().get("anyOfparentB"));
+        assertNotNull(filtered.getComponents().getSchemas().get("oneOfparentA"));
+        assertNotNull(filtered.getComponents().getSchemas().get("oneOfparentB"));
+        assertNotNull(filtered.getComponents().getSchemas().get("oneOfNestedParentA"));
+        assertNotNull(filtered.getComponents().getSchemas().get("oneOfNestedParentB"));
+        assertNotNull(filtered.getComponents().getSchemas().get("discriminatorParent"));
+        assertNotNull(filtered.getComponents().getSchemas().get("discriminatorMatchedChildA"));
+        assertNotNull(filtered.getComponents().getSchemas().get("discriminatorMatchedChildB"));
     }
 
     @Test