Fix NullPointerException in getUnusedSchemas(OpenAPI) (#10)

fix #9

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java

@@ -50,7 +50,6 @@ import org.slf4j.LoggerFactory;
 
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -89,14 +88,9 @@ public class ModelUtils {
     public static List<String> getUnusedSchemas(OpenAPI openAPI) {
         List<String> unusedSchemas = new ArrayList<String>();
 
-        // no model defined
-        if (openAPI.getComponents().getSchemas() == null) {
-            openAPI.getComponents().setSchemas(new HashMap<String, Schema>());
-        }
-
         // operations
         Map<String, PathItem> paths = openAPI.getPaths();
-        Map<String, Schema> schemas = openAPI.getComponents().getSchemas();
+        Map<String, Schema> schemas = getSchemas(openAPI);
 
         if (paths != null) {
             for (String pathname : paths.keySet()) {

modules/openapi-generator/src/test/java/org/openapitools/codegen/utils/ModelUtilsTest.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2018 OpenAPI-Generator Contributors (https://openapi-generator.tech)
+ * Copyright 2018 SmartBear Software
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.openapitools.codegen.utils;
+
+import io.swagger.parser.OpenAPIParser;
+import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.parser.core.models.ParseOptions;
+
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+import java.util.List;
+
+public class ModelUtilsTest {
+
+    @Test
+    public void testEnsureNoDuplicateProduces() {
+        final OpenAPI openAPI = new OpenAPIParser().readLocation("src/test/resources/3_0/ping.yaml", null, new ParseOptions()).getOpenAPI();
+        List<String> unusedSchemas = ModelUtils.getUnusedSchemas(openAPI);
+        Assert.assertEquals(unusedSchemas.size(), 0);
+    }
+}

modules/openapi-generator/src/test/resources/3_0/ping.yaml

@@ -0,0 +1,13 @@
+openapi: 3.0.1
+info:
+  title: ping test
+  version: '1.0'
+servers:
+  - url: 'http://localhost:8000/'
+paths:
+  /ping:
+    get:
+      operationId: pingGet
+      responses:
+        '201':
+          description: OK