fix header issue (#667)

Co-authored-by: xichen <[email protected]>

Author: shawncx

powershell/plugins/plugin-tweak-m4-model.ts

@@ -25,7 +25,8 @@ async function tweakModel(state: State): Promise<PwshModel> {
 }
 
 function addResponseHeaderSchema(model: CodeModel) {
-  // In remodler, each operations response headers will has its own scheam. Each header will be schema's property. But in m4, there won't be a schema for headers.
+  // In remodeler, each operations response headers will has its own scheam. Each header will be schema's property. 
+  // But in m4, if 'schema' is not explicitly defined, even 'headers' is specified, there won't be a schema for headers.
   // To keep backward compatiable, we will create headers schema here
 
   model.operationGroups.forEach((group) => {
@@ -34,6 +35,10 @@ function addResponseHeaderSchema(model: CodeModel) {
         return;
       }
       op.responses.forEach((resp) => {
+        if ((<any>resp).schema) {
+          return;
+        }
+
         const headers = resp.protocol.http?.headers as Array<HttpHeader>;
         if (headers === undefined) {
           return;

powershell/plugins/plugin-tweak-model.ts

@@ -188,7 +188,7 @@ async function tweakModelV2(state: State): Promise<PwshModel> {
             if ((response as any).schema.type === SchemaType.Object) {
               const respSchema = (response as any).schema as ObjectSchema;
               const curHeader = header as any;
-              const headerKey = curHeader as string;
+              const headerKey = curHeader.header as string;
 
               respSchema.language.default.hasHeaders = true;
 
@@ -197,7 +197,7 @@ async function tweakModelV2(state: State): Promise<PwshModel> {
                 state.message({ Channel: Channel.Debug, Text: `Adding header property '${headerKey}' to model ${respSchema.language.default.name}` });
 
                 // create a property for the header value
-                const newProperty = new Property(headerKey, curHeader.description, curHeader.schema);
+                const newProperty = new Property(headerKey, curHeader.description || '', curHeader.schema);
                 newProperty.language.default.required = false;
 
                 // mark it that it's a header-only property