1 files changed, 205 insertions, 0 deletions
diff --git a/packages/web-util/src/utils/http-impl.sw.ts b/packages/web-util/src/utils/http-impl.sw.ts
new file mode 100644
index 000000000..921acd63b
--- /dev/null
+++ b/packages/web-util/src/utils/http-impl.sw.ts
@@ -0,0 +1,205 @@
+/*
+ This file is part of GNU Taler
+ (C) 2022 Taler Systems S.A.
+
+ GNU 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.
+
+ GNU 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
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+/**
+ * Imports.
+ */
+import {
+  RequestThrottler,
+  TalerErrorCode,
+  TalerError,
+} from "@gnu-taler/taler-util";
+
+import {
+  Headers,
+  HttpRequestLibrary,
+  HttpRequestOptions,
+  HttpResponse,
+} from "@gnu-taler/taler-util/http";
+
+/**
+ * An implementation of the [[HttpRequestLibrary]] using the
+ * browser's XMLHttpRequest.
+ */
+export class ServiceWorkerHttpLib implements HttpRequestLibrary {
+  private throttle = new RequestThrottler();
+  private throttlingEnabled = true;
+
+  async fetch(
+    requestUrl: string,
+    options?: HttpRequestOptions,
+  ): Promise<HttpResponse> {
+    const requestMethod = options?.method ?? "GET";
+    const requestBody = options?.body;
+    const requestHeader = options?.headers;
+    const requestTimeout = options?.timeout ?? { d_ms: 2 * 1000 };
+
+    if (this.throttlingEnabled && this.throttle.applyThrottle(requestUrl)) {
+      const parsedUrl = new URL(requestUrl);
+      throw TalerError.fromDetail(
+        TalerErrorCode.WALLET_HTTP_REQUEST_THROTTLED,
+        {
+          requestMethod,
+          requestUrl,
+          throttleStats: this.throttle.getThrottleStats(requestUrl),
+        },
+        `request to origin ${parsedUrl.origin} was throttled`,
+      );
+    }
+
+    let myBody: BodyInit | undefined = undefined;
+    if (requestBody != null) {
+      if (typeof requestBody === "string") {
+        myBody = requestBody;
+      } else if (requestBody instanceof ArrayBuffer) {
+        myBody = requestBody;
+      } else if (ArrayBuffer.isView(requestBody)) {
+        myBody = requestBody;
+      } else if (typeof requestBody === "object") {
+        myBody = JSON.stringify(requestBody);
+      } else {
+        throw Error("unsupported request body type");
+      }
+    }
+
+    const controller = new AbortController();
+    let timeoutId: any | undefined;
+    if (requestTimeout.d_ms !== "forever") {
+      timeoutId = setTimeout(() => {
+        controller.abort(TalerErrorCode.WALLET_HTTP_REQUEST_GENERIC_TIMEOUT);
+      }, requestTimeout.d_ms);
+    }
+
+    try {
+      const response = await fetch(requestUrl, {
+        headers: requestHeader,
+        body: myBody,
+        method: requestMethod,
+        signal: controller.signal,
+      });
+
+      if (timeoutId) {
+        clearTimeout(timeoutId);
+      }
+
+      const headerMap = new Headers();
+      response.headers.forEach((value, key) => {
+        headerMap.set(key, value);
+      });
+      return {
+        headers: headerMap,
+        status: response.status,
+        requestMethod,
+        requestUrl,
+        json: makeJsonHandler(response, requestUrl, requestMethod),
+        text: makeTextHandler(response, requestUrl, requestMethod),
+        bytes: async () => (await response.blob()).arrayBuffer(),
+      };
+    } catch (e) {
+      if (controller.signal) {
+        throw TalerError.fromDetail(
+          controller.signal.reason,
+          {},
+          `request to ${requestUrl} timed out`,
+        );
+      }
+      throw e;
+    }
+  }
+
+  get(url: string, opt?: HttpRequestOptions): Promise<HttpResponse> {
+    return this.fetch(url, {
+      method: "GET",
+      ...opt,
+    });
+  }
+
+  postJson(
+    url: string,
+    body: any,
+    opt?: HttpRequestOptions,
+  ): Promise<HttpResponse> {
+    return this.fetch(url, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify(body),
+      ...opt,
+    });
+  }
+
+  stop(): void {
+    // Nothing to do
+  }
+}
+
+function makeTextHandler(
+  response: Response,
+  requestUrl: string,
+  requestMethod: string,
+) {
+  return async function getJsonFromResponse(): Promise<any> {
+    let respText;
+    try {
+      respText = await response.text();
+    } catch (e) {
+      throw TalerError.fromDetail(
+        TalerErrorCode.WALLET_RECEIVED_MALFORMED_RESPONSE,
+        {
+          requestUrl,
+          requestMethod,
+          httpStatusCode: response.status,
+        },
+        "Invalid JSON from HTTP response",
+      );
+    }
+    return respText;
+  };
+}
+
+function makeJsonHandler(
+  response: Response,
+  requestUrl: string,
+  requestMethod: string,
+) {
+  return async function getJsonFromResponse(): Promise<any> {
+    let responseJson;
+    try {
+      responseJson = await response.json();
+    } catch (e) {
+      throw TalerError.fromDetail(
+        TalerErrorCode.WALLET_RECEIVED_MALFORMED_RESPONSE,
+        {
+          requestUrl,
+          requestMethod,
+          httpStatusCode: response.status,
+        },
+        "Invalid JSON from HTTP response",
+      );
+    }
+    if (responseJson === null || typeof responseJson !== "object") {
+      throw TalerError.fromDetail(
+        TalerErrorCode.WALLET_RECEIVED_MALFORMED_RESPONSE,
+        {
+          requestUrl,
+          requestMethod,
+          httpStatusCode: response.status,
+        },
+        "Invalid JSON from HTTP response",
+      );
+    }
+    return responseJson;
+  };
+}