Fix parameter in PathItem (#639)

Author: jmini

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

@@ -896,8 +896,8 @@ private void processOperation(String resourcePath, String httpMethod, Operation
         if (path.getParameters() != null) {
             for (Parameter parameter : path.getParameters()) {
                 //skip propagation if a parameter with the same name is already defined at the operation level
-                if (!operationParameters.contains(generateParameterId(parameter)) && operation.getParameters() != null) {
-                    operation.getParameters().add(parameter);
+                if (!operationParameters.contains(generateParameterId(parameter))) {
+                    operation.addParametersItem(parameter);
                 }
             }
         }

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

@@ -0,0 +1,50 @@
+package org.openapitools.codegen;
+
+import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.oas.models.Operation;
+import io.swagger.v3.oas.models.PathItem;
+import io.swagger.v3.oas.models.Paths;
+import io.swagger.v3.oas.models.media.IntegerSchema;
+import io.swagger.v3.oas.models.media.StringSchema;
+import io.swagger.v3.oas.models.parameters.QueryParameter;
+import io.swagger.v3.oas.models.responses.ApiResponse;
+import io.swagger.v3.oas.models.responses.ApiResponses;
+
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+import java.util.List;
+import java.util.Map;
+
+public class DefaultGeneratorTest {
+
+    @Test
+    public void testProcessPaths() throws Exception {
+        OpenAPI openAPI = TestUtils.createOpenAPI();
+        openAPI.setPaths(new Paths());
+        openAPI.getPaths().addPathItem("path1/", new PathItem().get(new Operation().operationId("op1").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+        openAPI.getPaths().addPathItem("path2/", new PathItem().get(new Operation().operationId("op2").addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+        openAPI.getPaths().addPathItem("path3/", new PathItem().addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).get(new Operation().operationId("op3").addParametersItem(new QueryParameter().name("p2").schema(new IntegerSchema())).responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+        openAPI.getPaths().addPathItem("path4/", new PathItem().addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).get(new Operation().operationId("op4").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+
+        ClientOptInput opts = new ClientOptInput();
+        opts.setOpenAPI(openAPI);
+        opts.setConfig(new DefaultCodegen());
+        opts.setOpts(new ClientOpts());
+
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.opts(opts);
+        Map<String, List<CodegenOperation>> result = generator.processPaths(openAPI.getPaths());
+        Assert.assertEquals(result.size(), 1);
+        List<CodegenOperation> defaultList = result.get("Default");
+        Assert.assertEquals(defaultList.size(), 4);
+        Assert.assertEquals(defaultList.get(0).path, "path1/");
+        Assert.assertEquals(defaultList.get(0).allParams.size(), 0);
+        Assert.assertEquals(defaultList.get(1).path, "path2/");
+        Assert.assertEquals(defaultList.get(1).allParams.size(), 1);
+        Assert.assertEquals(defaultList.get(2).path, "path3/");
+        Assert.assertEquals(defaultList.get(2).allParams.size(), 2);
+        Assert.assertEquals(defaultList.get(3).path, "path4/");
+        Assert.assertEquals(defaultList.get(3).allParams.size(), 1);
+    }
+}