Merge pull request #207 from cyberhck/patch-1

test(ContentTypeMiddleware): add content-type middleware

src/middlewares/ContentTypeMiddleware.spec.ts

@@ -0,0 +1,21 @@
+import {ContentTypeMiddleware} from "./ContentTypeMiddleware";
+import {IFetchRequest} from "./FetchMiddleware";
+
+describe("ContentTypeMiddleware", () => {
+    it("should add a content type application/json by default", () => {
+        const spy = jest.fn((options: IFetchRequest) => {
+            const contentType = options.headers && options.headers["content-type"];
+            expect(contentType).toBe("application/json");
+        });
+        const mw = new ContentTypeMiddleware();
+        mw.process({}, spy);
+    });
+    it("should accept a content type in constructor if we want to change it", () => {
+        const spy = jest.fn((options: IFetchRequest) => {
+            const contentType = options.headers && options.headers["content-type"];
+            expect(contentType).toBe("text/plain");
+        });
+        const mw = new ContentTypeMiddleware("text/plain");
+        mw.process({}, spy);
+    });
+});

src/middlewares/ContentTypeMiddleware.ts

@@ -0,0 +1,15 @@
+import {IMiddleware} from "../Stack";
+import {IFetchRequest, IFetchResponse} from "./FetchMiddleware";
+
+export class ContentTypeMiddleware implements IMiddleware<IFetchRequest, Promise<IFetchResponse<any>>> {
+    constructor(private contentType: string = "application/json") {
+    }
+
+    public process(options: IFetchRequest, next: (nextOptions: IFetchRequest) => Promise<IFetchResponse<any>>): Promise<IFetchResponse<any>> {
+        if (!options.headers) {
+            options.headers = {};
+        }
+        options.headers["content-type"] = this.contentType;
+        return next(options);
+    }
+}

src/middlewares/index.ts

@@ -7,3 +7,4 @@ export * from "./FetchMiddleware";
 export * from "./MockMiddleware";
 export * from "./CacheMiddleware";
 export * from "./IncludeCredentialsMiddleware";
+export * from "./ContentTypeMiddleware";