[Postman Collections] Keep original header name (#15907)

* Define baseName for Postman headers

* Use header original name

* Commit regenerated files

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

@@ -226,6 +226,7 @@ public class PostmanCollectionCodegen extends DefaultCodegen implements CodegenC
                 // produces mediaType as `Accept` header (use first mediaType only)
                 String mediaType = codegenOperation.produces.get(0).get("mediaType");
                 CodegenParameter acceptHeader = new CodegenParameter();
+                acceptHeader.baseName = "Accept";
                 acceptHeader.paramName = "Accept";
                 CodegenProperty schema = new CodegenProperty();
                 schema.defaultValue = mediaType;
@@ -237,6 +238,8 @@ public class PostmanCollectionCodegen extends DefaultCodegen implements CodegenC
                 // consumes mediaType as `Content-Type` header (use first mediaType only)
                 String mediaType = codegenOperation.consumes.get(0).get("mediaType");
                 CodegenParameter contentTypeHeader = new CodegenParameter();
+
+                contentTypeHeader.baseName = "Content-Type";
                 contentTypeHeader.paramName = "Content-Type";
                 CodegenProperty schema = new CodegenProperty();
                 schema.defaultValue = mediaType;

modules/openapi-generator/src/main/resources/postman-collection/item.mustache

@@ -10,7 +10,7 @@
                                     "header": [
                                     {{#headerParams}}
                                         {
-                                            "key": "{{paramName}}",
+                                            "key": "{{baseName}}",
                                             "value": "{{schema.defaultValue}}"
                                         }{{^-last}},{{/-last}}
                                     {{/headerParams}}

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

@@ -6,10 +6,7 @@ import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import org.junit.Assert;
 import org.junit.Test;
-import org.openapitools.codegen.ClientOptInput;
+import org.openapitools.codegen.*;
-import org.openapitools.codegen.CodegenParameter;
-import org.openapitools.codegen.CodegenProperty;
-import org.openapitools.codegen.DefaultGenerator;
 import org.openapitools.codegen.config.CodegenConfigurator;
 import org.openapitools.codegen.languages.PostmanCollectionCodegen;
 
@@ -466,6 +463,32 @@ public class PostmanCollectionCodegenTest {
 
     }
 
+    @Test
+    public void testHeaderParameters() throws IOException {
+
+        File output = Files.createTempDirectory("postmantest_").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("postman-collection")
+                .setInputSpec("./src/test/resources/SampleProject.yaml")
+                .setInputSpec("src/test/resources/3_0/postman-collection/SampleProject.yaml")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        final ClientOptInput clientOptInput = configurator.toClientOptInput();
+        DefaultGenerator generator = new DefaultGenerator();
+        List<File> files = generator.opts(clientOptInput).generate();
+
+        files.forEach(File::deleteOnExit);
+
+        Path path = Paths.get(output + "/postman.json");
+        TestUtils.assertFileExists(path);
+        TestUtils.assertFileContains(path, "{ \"key\": \"Content-Type\", \"value\": \"application/json\"");
+        TestUtils.assertFileContains(path, "{ \"key\": \"Accept\", \"value\": \"application/json\"");
+        TestUtils.assertFileContains(path, "{ \"key\": \"Custom-Header\", \"value\": \"null\"");
+    }
+
+
     @Test
     public void testFormatDescription() {
 

modules/openapi-generator/src/test/resources/3_0/postman-collection/SampleProject.yaml

@@ -47,6 +47,11 @@ paths:
           schema:
             type: string
             example: 888
+        - description: Custom HTTP header
+          name: Custom-Header
+          in: header
+          schema:
+            type: string
 
       responses:
         '200':

samples/schema/postman-collection/postman.json

@@ -148,6 +148,10 @@
                                         {
                                             "key": "Accept",
                                             "value": "application/json"
+                                        },
+                                        {
+                                            "key": "Custom-Header",
+                                            "value": "null"
                                         }
                                     ],
                                     "body": {