requestOptions accepting function so that we can change options depen…

…ding on the request

packages/openapi-to-graphql/README.md

@@ -176,7 +176,7 @@ Resolver options:
 
 - `qs` (type: `object`, default: `{}`): Query parameters to be sent in every request to the API. Parameters defined in the OpenAPI Specification and set by these query parameters will be ignored by OpenAPI-to-GraphQL.
 
-- `requestOptions` (type: `object`, default: `{}`): Additional [options](https://github.com/request/request#requestoptions-callback), provided by the [`Request` module](https://github.com/request/request), that can be used to configure the HTTP calls that powers the generated GraphQL resolvers. A common use case for this option is to set up a web proxy with the `proxy` field. Parameters defined in the OpenAPI Specification and  set by this option will be ignored by OpenAPI-to-GraphQL. Additionally, the `headers` field has the feature of being used as a function. If used as a function, the following parameters will be exposed per-request: the operation's `method`, the operation's `path`, the API `title`, and `resolverParams` (the [GraphQL resolver's parameters](https://graphql.org/learn/execution/#root-fields-resolvers)). The function should return the desired headers.
+- `requestOptions` (type: `object` | `function`, default: `{}`): Additional [options](https://github.com/request/request#requestoptions-callback), provided by the [`Request` module](https://github.com/request/request), that can be used to configure the HTTP calls that powers the generated GraphQL resolvers. A common use case for this option is to set up a web proxy with the `proxy` field. Parameters defined in the OpenAPI Specification and  set by this option will be ignored by OpenAPI-to-GraphQL. Additionally, the `headers` field has the feature of being used as a function. If used as a function, the following parameters will be exposed per-request: the operation's `method`, the operation's `path`, the API `title`, and `resolverParams` (the [GraphQL resolver's parameters](https://graphql.org/learn/execution/#root-fields-resolvers)). The function should return the desired headers. If `requestOptions` is used as a function, the following parameters will be exposed per-request: the operation's `method`, the operation's `path`, the API `title`, and `resolverParams` (the [GraphQL resolver's parameters](https://graphql.org/learn/execution/#root-fields-resolvers)). It should return object of type [options](https://github.com/request/request#requestoptions-callback). If `requestOptions` is used as a function `url` and `method` can also be set.
 
 - `baseUrl` (type: `string`): Used to manually specify the base URL which all paths will be built on. Normally, OpenAPI-to-GraphQL will select a base URL from the [server object](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#serverObject) defined in the OAS. However, if the server object contains multiple URLs, OpenAPI-to-GraphQL will randomly select one. The purpose of this option is to provide greater control over the base URL in these situations, especially when the OAS cannot be modified. This option may also prove to be useful in testing and development.
 

packages/openapi-to-graphql/lib/resolver_builder.d.ts

@@ -7,7 +7,7 @@ import { ConnectOptions } from './types/options';
 import { Operation } from './types/operation';
 import { SubscriptionContext } from './types/graphql';
 import { PreprocessingData } from './types/preprocessing_data';
-import { RequestOptions } from './types/options';
+import { RequestOptions, RequestOptionsFunction } from './types/options';
 import { GraphQLFieldResolver } from 'graphql';
 import { IncomingHttpHeaders } from 'http';
 export declare const OPENAPI_TO_GRAPHQL = "_openAPIToGraphQL";
@@ -20,7 +20,7 @@ declare type GetResolverParams<TSource, TContext, TArgs> = {
     responseName?: string;
     data: PreprocessingData<TSource, TContext, TArgs>;
     baseUrl?: string;
-    requestOptions?: Partial<RequestOptions<TSource, TContext, TArgs>>;
+    requestOptions?: Partial<RequestOptions<TSource, TContext, TArgs>> | RequestOptionsFunction<TSource, TContext, TArgs>;
 };
 declare type GetSubscribeParams<TSource, TContext, TArgs> = {
     operation: Operation;

packages/openapi-to-graphql/lib/types/options.d.ts

@@ -43,6 +43,12 @@ export declare type RequestHeadersFunction<TSource, TContext, TArgs> = (method:
     context: TContext;
     info: GraphQLResolveInfo;
 }) => Headers;
+export declare type RequestOptionsFunction<TSource, TContext, TArgs> = (method: string, path: string, title: string, resolverParams?: {
+    source: TSource;
+    args: TArgs;
+    context: TContext;
+    info: GraphQLResolveInfo;
+}) => Partial<NodeRequest.CoreOptions>;
 /**
  * We rely on the Request library in order to make resolver API calls.
  *
@@ -175,7 +181,7 @@ export declare type InternalOptions<TSource, TContext, TArgs> = {
      *
      * Based on: https://github.com/request/request#requestoptions-callback
      */
-    requestOptions?: Partial<RequestOptions<TSource, TContext, TArgs>>;
+    requestOptions?: Partial<RequestOptions<TSource, TContext, TArgs>> | RequestOptionsFunction<TSource, TContext, TArgs>;
     /**
      * Allows to override or add options to the PubSub connect object used to make
      * publish/subscribe to the API backend.

packages/openapi-to-graphql/src/index.ts

@@ -36,6 +36,7 @@ import {
   InternalOptions,
   Report,
   ConnectOptions,
+  RequestOptionsFunction,
   RequestOptions
 } from './types/options'
 import { Oas3 } from './types/oas3'
@@ -640,7 +641,9 @@ function getFieldForOperation<TSource, TContext, TArgs>(
   operation: Operation,
   baseUrl: string,
   data: PreprocessingData<TSource, TContext, TArgs>,
-  requestOptions: Partial<RequestOptions<TSource, TContext, TArgs>>,
+  requestOptions:
+    | Partial<RequestOptions<TSource, TContext, TArgs>>
+    | RequestOptionsFunction<TSource, TContext, TArgs>,
   connectOptions: ConnectOptions
 ): GraphQLFieldConfig<TSource, TContext | SubscriptionContext, TArgs> {
   // Create GraphQL Type for response:

packages/openapi-to-graphql/src/resolver_builder.ts

@@ -14,7 +14,7 @@ import { Operation } from './types/operation'
 import { SubscriptionContext } from './types/graphql'
 import { PreprocessingData } from './types/preprocessing_data'
 import * as NodeRequest from 'request'
-import { RequestOptions } from './types/options'
+import { RequestOptions, RequestOptionsFunction } from './types/options'
 
 // Imports:
 import * as Oas3Tools from './oas_3_tools'
@@ -57,7 +57,9 @@ type GetResolverParams<TSource, TContext, TArgs> = {
   responseName?: string
   data: PreprocessingData<TSource, TContext, TArgs>
   baseUrl?: string
-  requestOptions?: Partial<RequestOptions<TSource, TContext, TArgs>>
+  requestOptions?:
+    | Partial<RequestOptions<TSource, TContext, TArgs>>
+    | RequestOptionsFunction<TSource, TContext, TArgs>
 }
 
 type GetSubscribeParams<TSource, TContext, TArgs> = {
@@ -487,7 +489,7 @@ export function getResolver<TSource, TContext, TArgs>({
       args,
       data
     )
-    const url = baseUrl + path
+    let url = baseUrl + path
 
     /**
      * The Content-Type and Accept property should not be changed because the
@@ -510,21 +512,41 @@ export function getResolver<TSource, TContext, TArgs>({
 
     let options: NodeRequest.OptionsWithUrl
     if (requestOptions) {
+      let requestOptionsVal: any = requestOptions
+      let method = operation.method
+      if (typeof requestOptions === 'function') {
+        requestOptionsVal = requestOptions(method, path, title, {
+          source,
+          args,
+          context,
+          info
+        })
+
+        if (
+          requestOptionsVal.url &&
+          requestOptionsVal.url.toString().trim().length > 0
+        ) {
+          url = requestOptionsVal.url.toString().trim()
+        }
+        if (requestOptionsVal.method && requestOptionsVal.method.length > 0) {
+          method = Oas3Tools.methodToHttpMethod(requestOptionsVal.method)
+        }
+      }
       options = {
-        ...requestOptions,
-        method: operation.method,
+        ...requestOptionsVal,
+        method: method,
         url // Must be after the requestOptions spread as url is a mandatory field so undefined may be used
       }
 
       options.headers = {} // Handle requestOptions.header later if applicable
       options.qs = {} // Handle requestOptions.qs later if applicable
 
-      if (requestOptions.headers) {
+      if (requestOptionsVal.headers) {
         // requestOptions.headers may be either an object or a function
-        if (typeof requestOptions.headers === 'object') {
-          Object.assign(options.headers, headers, requestOptions.headers)
-        } else if (typeof requestOptions.headers === 'function') {
-          const headers = requestOptions.headers(method, path, title, {
+        if (typeof requestOptionsVal.headers === 'object') {
+          Object.assign(options.headers, headers, requestOptionsVal.headers)
+        } else if (typeof requestOptionsVal.headers === 'function') {
+          const headers = requestOptionsVal.headers(method, path, title, {
             source,
             args,
             context,
@@ -539,8 +561,8 @@ export function getResolver<TSource, TContext, TArgs>({
         options.headers = headers
       }
 
-      if (requestOptions.qs) {
-        Object.assign(options.qs, qs, requestOptions.qs)
+      if (requestOptionsVal.qs) {
+        Object.assign(options.qs, qs, requestOptionsVal.qs)
       } else {
         options.qs = qs
       }

packages/openapi-to-graphql/src/types/options.ts

@@ -60,6 +60,18 @@ export type RequestHeadersFunction<TSource, TContext, TArgs> = (
   }
 ) => Headers
 
+export type RequestOptionsFunction<TSource, TContext, TArgs> = (
+  method: string,
+  path: string,
+  title: string,
+  resolverParams?: {
+    source: TSource
+    args: TArgs
+    context: TContext
+    info: GraphQLResolveInfo
+  }
+) => Partial<NodeRequest.CoreOptions>
+
 /**
  * We rely on the Request library in order to make resolver API calls.
  *
@@ -219,7 +231,9 @@ export type InternalOptions<TSource, TContext, TArgs> = {
    *
    * Based on: https://github.com/request/request#requestoptions-callback
    */
-  requestOptions?: Partial<RequestOptions<TSource, TContext, TArgs>>
+  requestOptions?:
+    | Partial<RequestOptions<TSource, TContext, TArgs>>
+    | RequestOptionsFunction<TSource, TContext, TArgs>
 
   /**
    * Allows to override or add options to the PubSub connect object used to make