Merge pull request #327 from chris-prop/issue-326

refs #326 - Resolve header references

Author: frantuma

src/main/java/io/swagger/codegen/v3/generators/DefaultCodegenConfig.java

@@ -2031,7 +2031,11 @@ public CodegenOperation fromOperation(String path, String httpMethod, Operation
                         codegenOperation.returnTypeIsPrimitive = true;
                     }
                 }
-                addHeaders(methodResponse, codegenOperation.responseHeaders);
+                Map<String, Header> componentHeaders = null;
+                if ((openAPI != null) && (openAPI.getComponents() != null)) {
+                    componentHeaders = openAPI.getComponents().getHeaders();
+                }
+                addHeaders(methodResponse, codegenOperation.responseHeaders, componentHeaders);
             }
         }
 
@@ -2259,7 +2263,11 @@ public CodegenResponse fromResponse(String responseCode, ApiResponse response) {
         if (response.getExtensions() != null && !response.getExtensions().isEmpty()) {
             codegenResponse.vendorExtensions.putAll(response.getExtensions());
         }
-        addHeaders(response, codegenResponse.headers);
+        Map<String, Header> componentHeaders = null;
+        if ((openAPI != null) && (openAPI.getComponents() != null)) {
+            componentHeaders = openAPI.getComponents().getHeaders();
+        }
+        addHeaders(response, codegenResponse.headers, componentHeaders);
         codegenResponse.getVendorExtensions().put(CodegenConstants.HAS_HEADERS_EXT_NAME, !codegenResponse.headers.isEmpty());
 
         if (responseSchema != null) {
@@ -2855,10 +2863,18 @@ protected List<Map<String, Object>> toExamples(Map<String, Object> examples) {
         return output;
     }
 
-    private void addHeaders(ApiResponse response, List<CodegenProperty> target) {
+    private void addHeaders(ApiResponse response, List<CodegenProperty> target, Map<String, Header> componentHeaders) {
         if (response.getHeaders() != null) {
             for (Map.Entry<String, Header> headers : response.getHeaders().entrySet()) {
-                target.add(fromProperty(headers.getKey(), headers.getValue().getSchema()));
+                Header header = headers.getValue();
+                Schema schema;
+                if ((header.get$ref() != null) && (componentHeaders != null)) {
+                    String ref = OpenAPIUtil.getSimpleRef(header.get$ref());
+                    schema = componentHeaders.get(ref).getSchema();
+                } else {
+                    schema = header.getSchema();
+                }
+                target.add(fromProperty(headers.getKey(), schema));
             }
         }
     }
@@ -3951,11 +3967,11 @@ protected void addConsumesInfo(Operation operation, CodegenOperation codegenOper
             String bodyName = OpenAPIUtil.getSimpleRef(body.get$ref());
             body = openAPI.getComponents().getRequestBodies().get(bodyName);
         }
-        
+
         if (body.getContent() == null || body.getContent().isEmpty()) {
             return;
         }
-        
+
         Set<String> consumes = body.getContent().keySet();
         List<Map<String, String>> mediaTypeList = new ArrayList<>();
         int count = 0;
@@ -4101,7 +4117,7 @@ protected String getCollectionFormat(Parameter parameter) {
         if (parameter.getExplode() == null || parameter.getExplode()) {
             return "multi";
         }
-        
+
         // Form is the default, if no style is specified.
         if (parameter.getStyle() == null || Parameter.StyleEnum.FORM.equals(parameter.getStyle())) {
             return "csv";

src/test/java/io/swagger/codegen/v3/generators/DefaultCodegenConfigTest.java

@@ -5,10 +5,13 @@
 import io.swagger.codegen.v3.CodegenOperation;
 import io.swagger.codegen.v3.CodegenParameter;
 import io.swagger.codegen.v3.CodegenProperty;
+import io.swagger.codegen.v3.CodegenResponse;
 import io.swagger.codegen.v3.CodegenType;
+import io.swagger.v3.oas.models.Components;
 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.headers.Header;
 import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.Content;
 import io.swagger.v3.oas.models.media.IntegerSchema;
@@ -17,13 +20,15 @@
 import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.oas.models.parameters.Parameter;
 import io.swagger.v3.oas.models.parameters.RequestBody;
+import io.swagger.v3.oas.models.responses.ApiResponse;
 import io.swagger.v3.parser.OpenAPIV3Parser;
 
 import org.testng.Assert;
 import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
 import java.math.BigDecimal;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 
@@ -256,7 +261,55 @@ public void testOptionalFormParams() {
         List<CodegenParameter> requiredParams = codegenOp.getRequiredParams();
         Assert.assertTrue(requiredParams == null || requiredParams.size() == 0);
     }
-    
+
+    @Test
+    public void testFromResponse_inlineHeaders() {
+        final String RESPONSE_CODE = "200";
+
+        ApiResponse apiResponse = new ApiResponse();
+        Header inlineHeader = new Header().description("This is header1").schema(new Schema().type("string").example("header_val"));
+        apiResponse.addHeaderObject("header1", inlineHeader);
+
+        OpenAPI openAPI = new OpenAPI().components(new Components().responses(new HashMap<>()));
+        openAPI.getComponents().addHeaders("ref-header1", inlineHeader);
+
+        final DefaultCodegenConfig codegen = new P_DefaultCodegenConfig();
+        codegen.preprocessOpenAPI(openAPI);
+        CodegenResponse codegenResponse = codegen.fromResponse(RESPONSE_CODE, apiResponse);
+
+        Assert.assertEquals(codegenResponse.code, RESPONSE_CODE);
+
+        CodegenProperty headerProperty = codegenResponse.headers.get(0);
+        Assert.assertNotNull(headerProperty);
+        Assert.assertEquals(headerProperty.description, inlineHeader.getSchema().getDescription());
+        Assert.assertEquals(headerProperty.datatype, "String");
+        Assert.assertEquals(headerProperty.example, inlineHeader.getSchema().getExample());
+    }
+
+    @Test
+    public void testFromResponse_referenceHeaders() {
+        final String RESPONSE_CODE = "200";
+
+        ApiResponse apiResponse = new ApiResponse();
+        apiResponse.addHeaderObject("header1", new Header().$ref("#/components/ref-header1"));
+
+        OpenAPI openAPI = new OpenAPI().components(new Components().responses(new HashMap<>()));
+        Header referencedHeader = new Header().schema(new Schema().description("This is header1").type("string").example("header_val"));
+        openAPI.getComponents().addHeaders("ref-header1", referencedHeader);
+
+        final DefaultCodegenConfig codegen = new P_DefaultCodegenConfig();
+        codegen.preprocessOpenAPI(openAPI);
+        CodegenResponse codegenResponse = codegen.fromResponse(RESPONSE_CODE, apiResponse);
+
+        Assert.assertEquals(codegenResponse.code, RESPONSE_CODE);
+
+        CodegenProperty headerProperty = codegenResponse.headers.get(0);
+        Assert.assertNotNull(headerProperty);
+        Assert.assertEquals(headerProperty.description, referencedHeader.getSchema().getDescription());
+        Assert.assertEquals(headerProperty.datatype, "String");
+        Assert.assertEquals(headerProperty.example, referencedHeader.getSchema().getExample());
+    }
+
     private static class P_DefaultCodegenConfig extends DefaultCodegenConfig{
         @Override
         public String getArgumentsLocation() {