initial commit

src/utils/enum.js

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+/*
+Copyright 2020 Bruno Windels <bruno@windels.cloud>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+export function createEnum(...values) {
+    const obj = {};
+    for (const value of values) {
+        if (typeof value !== "string") {
+            throw new Error("Invalid enum value name" + value?.toString());
+        }
+        obj[value] = value;
+    }
+    return Object.freeze(obj);
+}

src/utils/error.js

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+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+export class ConnectionError extends Error {
+    constructor(message, isTimeout) {
+        super(message || "ConnectionError");
+        this.isTimeout = isTimeout;
+    }
+
+    get name() {
+        return "ConnectionError";
+    }
+}
+
+export class AbortError extends Error {
+    get name() {
+        return "AbortError";
+    }
+}

src/utils/xhr.js

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+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {
+    AbortError,
+    ConnectionError
+} from "./error.js";
+
+function addCacheBuster(urlStr, random = Math.random) {
+    // XHR doesn't have a good way to disable cache,
+    // so add a random query param
+    // see https://davidtranscend.com/blog/prevent-ie11-cache-ajax-requests/
+    if (urlStr.includes("?")) {
+        urlStr = urlStr + "&";
+    } else {
+        urlStr = urlStr + "?";
+    }
+    return urlStr + `_cacheBuster=${Math.ceil(random() * Number.MAX_SAFE_INTEGER)}`;
+}
+
+class RequestResult {
+    constructor(promise, xhr) {
+        this._promise = promise;
+        this._xhr = xhr;
+    }
+
+    abort() {
+        this._xhr.abort();
+    }
+
+    response() {
+        return this._promise;
+    }
+}
+
+function createXhr(url, {method, headers, timeout, uploadProgress}) {
+    const xhr = new XMLHttpRequest();
+    xhr.open(method, url);
+
+    if (headers) {
+        for(const [name, value] of headers.entries()) {
+            try {
+                xhr.setRequestHeader(name, value);
+            } catch (err) {
+                console.info(`Could not set ${name} header: ${err.message}`);
+            }
+        }
+    }
+    if (timeout) {
+        xhr.timeout = timeout;
+    }
+
+    if (uploadProgress) {
+        xhr.upload.addEventListener("progress", evt => uploadProgress(evt.loaded));
+    }
+
+    return xhr;
+}
+
+function xhrAsPromise(xhr, method, url) {
+    return new Promise((resolve, reject) => {
+        xhr.addEventListener("load", () => resolve(xhr));
+        xhr.addEventListener("abort", () => reject(new AbortError()));
+        xhr.addEventListener("error", () => reject(new ConnectionError(`Error ${method} ${url}`)));
+        xhr.addEventListener("timeout", () => reject(new ConnectionError(`Timeout ${method} ${url}`, true)));
+    });
+}
+
+export function xhrRequest(url, options) {
+    let {cache, body, method} = options;
+    if (!cache) {
+        url = addCacheBuster(url);
+    }
+    const xhr = createXhr(url, options);
+    const promise = xhrAsPromise(xhr, method, url).then(xhr => {
+        const {status} = xhr;
+        const body = JSON.parse(xhr.responseText);
+        return {status, body};
+    });
+    
+    xhr.send(body || null);
+
+    return new RequestResult(promise, xhr);
+}