1 files changed, 109 insertions, 0 deletions
diff --git a/src/util/http.ts b/src/util/http.ts
new file mode 100644
index 000000000..a2bfab279
--- /dev/null
+++ b/src/util/http.ts
@@ -0,0 +1,109 @@
+/*
+ This file is part of TALER
+ (C) 2016 GNUnet e.V.
+
+ TALER is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+/**
+ * Helpers for doing XMLHttpRequest-s that are based on ES6 promises.
+ * Allows for easy mocking for test cases.
+ */
+
+/**
+ * An HTTP response that is returned by all request methods of this library.
+ */
+export interface HttpResponse {
+  status: number;
+  responseJson: object & any;
+}
+
+/**
+ * The request library is bundled into an interface to make mocking easy.
+ */
+export interface HttpRequestLibrary {
+  get(url: string): Promise<HttpResponse>;
+
+  postJson(url: string, body: any): Promise<HttpResponse>;
+}
+
+/**
+ * An implementation of the [[HttpRequestLibrary]] using the
+ * browser's XMLHttpRequest.
+ */
+export class BrowserHttpLib implements HttpRequestLibrary {
+  private req(
+    method: string,
+    url: string,
+    options?: any,
+  ): Promise<HttpResponse> {
+    return new Promise<HttpResponse>((resolve, reject) => {
+      const myRequest = new XMLHttpRequest();
+      myRequest.open(method, url);
+      if (options && options.req) {
+        myRequest.send(options.req);
+      } else {
+        myRequest.send();
+      }
+
+      myRequest.onerror = e => {
+        console.error("http request error");
+        reject(Error("could not make XMLHttpRequest"));
+      };
+
+      myRequest.addEventListener("readystatechange", e => {
+        if (myRequest.readyState === XMLHttpRequest.DONE) {
+          if (myRequest.status === 0) {
+            reject(Error("HTTP Request failed (status code 0, maybe URI scheme is wrong?)"))
+            return;
+          }
+          if (myRequest.status != 200) {
+            reject(
+              Error(
+                `HTTP Response with unexpected status code ${myRequest.status}: ${myRequest.statusText}`,
+              ),
+            );
+            return;
+          }
+          let responseJson;
+          try {
+            responseJson = JSON.parse(myRequest.responseText);
+          } catch (e) {
+            reject(Error("Invalid JSON from HTTP response"));
+            return;
+          }
+          if (responseJson === null || typeof responseJson !== "object") {
+            reject(Error("Invalid JSON from HTTP response"));
+            return;
+          }
+          const resp = {
+            responseJson: responseJson,
+            status: myRequest.status,
+          };
+          resolve(resp);
+        }
+      });
+    });
+  }
+
+  get(url: string) {
+    return this.req("get", url);
+  }
+
+  postJson(url: string, body: any) {
+    return this.req("post", url, { req: JSON.stringify(body) });
+  }
+
+  postForm(url: string, form: any) {
+    return this.req("post", url, { req: form });
+  }
+}