fix: _isSetType now detects indirect Set implementations

modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/AbstractModelConverter.java

@@ -114,17 +114,16 @@ protected String _subTypeName(NamedType type) {
     }
 
     protected boolean _isSetType(Class<?> cls) {
-        if (cls != null) {
-
-            if (java.util.Set.class.equals(cls)) {
+        if (cls == null) {
+            return false;
+        }
+        if (java.util.Set.class.isAssignableFrom(cls)) {
+            return true;
+        }
+        // check for scala Set as well - to avoid bringing in scala runtime
+        for (Class<?> a : cls.getInterfaces()) {
+            if ("interface scala.collection.Set".equals(a.toString())) {
                 return true;
-            } else {
-                for (Class<?> a : cls.getInterfaces()) {
-                    // this is dirty and ugly and needs to be extended into a scala model converter.  But to avoid bringing in scala runtime...
-                    if (java.util.Set.class.equals(a) || "interface scala.collection.Set".equals(a.toString())) {
-                        return true;
-                    }
-                }
             }
         }
         return false;

modules/swagger-core/src/test/java/io/swagger/v3/core/converting/IsSetTypeTest.java

@@ -0,0 +1,69 @@
+package io.swagger.v3.core.converting;
+
+import io.swagger.v3.core.jackson.AbstractModelConverter;
+import io.swagger.v3.core.util.Json;
+import org.testng.annotations.Test;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeSet;
+
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertTrue;
+
+public class IsSetTypeTest {
+
+    private static class TestModelConverter extends AbstractModelConverter {
+        protected TestModelConverter() {
+            super(Json.mapper());
+        }
+
+        public boolean isSetType(Class<?> cls) {
+            return _isSetType(cls);
+        }
+    }
+
+    private final TestModelConverter converter = new TestModelConverter();
+
+    @Test
+    public void testIsSetTypeWithNull() {
+        assertFalse(converter.isSetType(null));
+    }
+
+    @Test
+    public void testIsSetTypeWithSetInterface() {
+        assertTrue(converter.isSetType(Set.class));
+    }
+
+    @Test
+    public void testIsSetTypeWithHashSet() {
+        assertTrue(converter.isSetType(HashSet.class));
+    }
+
+    @Test
+    public void testIsSetTypeWithLinkedHashSet() {
+        assertTrue(converter.isSetType(LinkedHashSet.class));
+    }
+
+    @Test
+    public void testIsSetTypeWithTreeSet() {
+        assertTrue(converter.isSetType(TreeSet.class));
+    }
+
+    @Test
+    public void testIsSetTypeWithNonSetCollection() {
+        assertFalse(converter.isSetType(List.class));
+        assertFalse(converter.isSetType(ArrayList.class));
+    }
+
+    @Test
+    public void testIsSetTypeWithNonCollection() {
+        assertFalse(converter.isSetType(String.class));
+        assertFalse(converter.isSetType(Integer.class));
+        assertFalse(converter.isSetType(Map.class));
+    }
+}