feat(endpoints): only create GraphQLEndpoint if endpoint is not already GraphQLEndpoint

The current implementation assumed an endpoint to be GraphQLConfigEndpointConfig. However, if an
extension has already resolved the endpoint configuration to an actual GraphQLEndpoint, this will
overwrite that. The new implementation only creates a new GraphQLEndpoint object, if the endpoint
was not already resolved.

Author: kbrandwijk

src/extensions/endpoints/EndpointsExtension.ts

@@ -26,7 +26,7 @@ export type GraphQLConfigEnpointsMapData = {
 }
 
 export type GraphQLConfigEnpointsMap = {
-  [env: string]: GraphQLConfigEnpointConfig
+  [env: string]: GraphQLConfigEnpointConfig | GraphQLEndpoint
 }
 
 export type GraphQLConfigEnpointsData = GraphQLConfigEnpointsMapData
@@ -68,7 +68,11 @@ export class GraphQLEndpointsExtension {
   ): GraphQLEndpoint {
     const endpoint = this.getRawEndpoint(endpointName)
     try {
-      return new GraphQLEndpoint(resolveEnvsInValues(endpoint, env))
+      const resolved = resolveEnvsInValues(endpoint, env)
+      if (!(resolved instanceof GraphQLEndpoint)) {
+        return new GraphQLEndpoint(resolved)
+      }
+      return resolved
     } catch (e) {
       e.message = `${this.configPath}: ${e.message}`
       throw e
@@ -99,7 +103,7 @@ export class GraphQLEndpointsExtension {
       )
     }
 
-    if (!endpoint.url) {
+    if (!endpoint.url && !(endpoint instanceof GraphQLEndpoint)) {
       throw new Error(
         `${this
           .configPath}: "url" is required but is not specified for "${endpointName}" endpoint`,

src/extensions/endpoints/resolveRefString.ts

@@ -15,7 +15,6 @@ export function resolveEnvsInValues<T extends any>(
   config: T,
   env: { [name: string]: string | undefined },
 ): T {
-  config = Object.assign({}, config)
   for (let key in config) {
     const value = config[key]
     if (typeof value === 'string') {