fix: send headers from .setHeaders to server (#202)

closes #203

src/index.ts

@@ -7,6 +7,21 @@ import { Headers, RequestInit, Response } from './types.dom'
 
 export { ClientError } from './types'
 
+const transformHeaders = (headers: RequestInit["headers"]): Record<string, string> => {
+  let oHeaders: Record<string, string> = {};
+  if (headers) {
+    if (headers instanceof Headers) {
+      headers.forEach((v, k) => { oHeaders[k] = v })
+    } else if (headers instanceof Array) {
+      headers.forEach(([k, v]) => { oHeaders[k] = v })
+    } else {
+      oHeaders = headers as Record<string, string>
+    }
+  }
+
+  return oHeaders
+};
+
 /**
  * todo
  */
@@ -24,14 +39,14 @@ export class GraphQLClient {
     variables?: V
   ): Promise<{ data?: T; extensions?: any; headers: Headers; status: number; errors?: GraphQLError[] }> {
     const { headers, ...others } = this.options
-
+    const oHeaders = transformHeaders(headers)
     const body = createRequestBody(query, variables)
 
     const response = await fetch(this.url, {
       method: 'POST',
       headers: {
         ...(typeof body === 'string' ? { 'Content-Type': 'application/json' } : {}),
-        ...headers,
+        ...oHeaders,
       },
       body,
       ...others,
@@ -56,6 +71,7 @@ export class GraphQLClient {
    */
   async request<T = any, V = Variables>(document: RequestDocument, variables?: V): Promise<T> {
     const { headers, ...others } = this.options
+    const oHeaders = transformHeaders(headers)
     const resolvedDoc = resolveRequestDocument(document)
 
     const body = createRequestBody(resolvedDoc, variables)
@@ -64,7 +80,7 @@ export class GraphQLClient {
       method: 'POST',
       headers: {
         ...(typeof body === 'string' ? { 'Content-Type': 'application/json' } : {}),
-        ...headers,
+        ...oHeaders,
       },
       body,
       ...others,
@@ -80,7 +96,7 @@ export class GraphQLClient {
     }
   }
 
-  setHeaders(headers: Response['headers']): GraphQLClient {
+  setHeaders(headers: RequestInit['headers']): GraphQLClient {
     this.options.headers = headers
     return this
   }