Allow arbitrary fetch() options to be specified

Previously we could only set the JWT token on the underlying fetch()
call. Now any model can enhance the fetch options by overriding
`getFetchOptions()`.

Author: wadetandy

.gitignore

@@ -6,3 +6,4 @@ lib
 lib-esm
 _bundles
 yarn.lock
+yarn-error.log

src/model.ts

@@ -12,7 +12,7 @@ import IncludeDirective from './util/include-directive';
 import DirtyChecker from './util/dirty-check';
 import ValidationErrors from './util/validation-errors';
 import relationshipIdentifiersFor from './util/relationship-identifiers';
-import Request from './request';
+import Request, { FetchOptions } from './request';
 import * as _cloneDeep from './util/clonedeep';
 let cloneDeep: any = (<any>_cloneDeep).default || _cloneDeep;
 if (cloneDeep.default) {
@@ -70,6 +70,12 @@ export default class Model {
     }
   }
 
+  static getFetchOptions() : FetchOptions {
+    return {
+      jwt: this.getJWT()
+    }
+  }
+
   static getJWTOwner() : typeof Model {
     if (this.isJWTOwner) {
       return this;

src/request.ts

@@ -1,27 +1,33 @@
 import Config from './configuration';
 import colorize from './util/colorize';
+import cloneDeep from './util/clonedeep';
+
+// RequestInit is the type expected by `fetch()` API. 
+export interface FetchOptions extends RequestInit {
+  jwt? : string | undefined
+}
 
 export default class Request {
-  get(url : string, options: Object) : Promise<any> {
+  get(url : string, options: FetchOptions) : Promise<any> {
     options['method'] = 'GET';
     return this._fetchWithLogging(url, options);
   }
 
-  post(url: string, payload: Object, options: Object) : Promise<any> {
+  post(url: string, payload: Object, options: FetchOptions) : Promise<any> {
     options['method'] = 'POST';
     options['body']   = JSON.stringify(payload);
 
     return this._fetchWithLogging(url, options);
   }
 
-  put(url: string, payload: Object, options: Object) : Promise<any> {
+  put(url: string, payload: Object, options: FetchOptions) : Promise<any> {
     options['method'] = 'PUT';
     options['body']   = JSON.stringify(payload);
 
     return this._fetchWithLogging(url, options);
   }
 
-  delete(url: string, options: Object) : Promise<any> {
+  delete(url: string, options: FetchOptions) : Promise<any> {
     options['method'] = 'DELETE';
     return this._fetchWithLogging(url, options);
   }
@@ -36,7 +42,7 @@ export default class Request {
     Config.logger.debug(colorize('bold', JSON.stringify(responseJSON, null, 4)));
   }
 
-  private _fetchWithLogging(url: string, options: Object) : Promise<any> {
+  private _fetchWithLogging(url: string, options: FetchOptions) : Promise<any> {
     this._logRequest(options['method'], url);
     let promise = this._fetch(url, options);
     promise.then((response : any) => {
@@ -45,10 +51,13 @@ export default class Request {
     return promise;
   }
 
-  private _fetch(url: string, options: Object) : Promise<any> {
+  private _fetch(url: string, opts: FetchOptions) : Promise<any> {
     return new Promise((resolve, reject) => {
+      // Clone options since we are changing the object
+      let options : RequestInit = cloneDeep(opts as RequestInit)
+
       let headers = this.buildHeaders(options);
-      options['headers'] = headers;
+      options.headers = headers;
 
       let fetchPromise = fetch(url, options);
       fetchPromise.then((response) => {
@@ -57,17 +66,24 @@ export default class Request {
           resolve(response);
         }).catch((e) => { throw(e); });
       });
+
       fetchPromise.catch(reject);
     });
   }
 
-  private buildHeaders(options: Object) : any {
+  private buildHeaders(options: FetchOptions) : any {
     let headers = {};
+
+    if (typeof options.headers == 'object') {
+      headers = options.headers 
+    }
+
     headers['Accept'] = 'application/json';
     headers['Content-Type'] = 'application/json';
 
-    if (options['jwt']) {
-      headers['Authorization'] = `Token token="${options['jwt']}"`;
+    if (options.jwt) {
+      headers['Authorization'] = `Token token="${options.jwt}"`;
+      delete options.jwt
     }
 
     return headers;

src/scope.ts

@@ -219,9 +219,9 @@ export default class Scope {
       url = `${url}?${qp}`;
     }
     let request = new Request();
-    let jwt = this.model.getJWT();
+    let fetchOpts = this.model.getFetchOptions()
 
-    return request.get(url, { jwt }).then((response) => {
+    return request.get(url, fetchOpts).then((response) => {
       let jwtHeader = response.headers.get('X-JWT');
       if (jwtHeader) {
         this.model.setJWT(jwtHeader);

test/unit/model-test.ts

@@ -134,6 +134,20 @@ describe('Model', function() {
     });
   });
 
+  describe('#getFetchOptions', function() {
+    beforeEach(function() {
+      ApplicationRecord.jwt = 'g3tm3';
+    });
+
+    afterEach(function() {
+      ApplicationRecord.jwt = null;
+    });
+
+    it('includes the jwt', function() {
+      expect(Author.getFetchOptions().jwt).to.eq('g3tm3');
+    });
+  })
+
   describe('#isType', function() {
     it('checks the jsonapiType of class', function() {
       instance = new Author()