ref: Convert some files to TS (#11929)

react/features/base/util/loadScript.native.ts

@@ -0,0 +1,62 @@
+/**
+ * Default timeout for loading scripts.
+ */
+const DEFAULT_TIMEOUT = 5000;
+
+/**
+ * Loads a script from a specific URL. React Native cannot load a JS
+ * file/resource/URL via a <script> HTML element, so the implementation
+ * fetches the specified {@code url} as plain text using {@link fetch()} and
+ * then evaluates the fetched string as JavaScript code (using {@link eval()}).
+ *
+ * @param {string} url - The absolute URL from which the script is to be
+ * (down)loaded.
+ * @param {number} [timeout] - The timeout in millisecnods after which the
+ * loading of the specified {@code url} is to be aborted/rejected (if not
+ * settled yet).
+ * @param {boolean} skipEval - Whether we want to skip evaluating the loaded content or not.
+ * @returns {void}
+ */
+export async function loadScript(
+        url: string, timeout: number = DEFAULT_TIMEOUT, skipEval = false): Promise<any> {
+    // XXX The implementation of fetch on Android will throw an Exception on
+    // the Java side which will break the app if the URL is invalid (which
+    // the implementation of fetch on Android calls 'unexpected url'). In
+    // order to try to prevent the breakage of the app, try to fail on an
+    // invalid URL as soon as possible.
+    const { hostname, pathname, protocol } = new URL(url);
+
+    // XXX The standard URL implementation should throw an Error if the
+    // specified URL is relative. Unfortunately, the polyfill used on
+    // react-native does not.
+    if (!hostname || !pathname || !protocol) {
+        throw new Error(`unexpected url: ${url}`);
+    }
+
+    const controller = new AbortController();
+    const signal = controller.signal;
+
+    const timer = setTimeout(() => {
+        controller.abort();
+    }, timeout);
+
+    const response = await fetch(url, { signal });
+
+    // If the timeout hits the above will raise AbortError.
+
+    clearTimeout(timer);
+
+    switch (response.status) {
+    case 200: {
+        const txt = await response.text();
+
+        if (skipEval) {
+            return txt;
+        }
+
+        return eval.call(window, txt); // eslint-disable-line no-eval
+    }
+    default:
+        throw new Error(`loadScript error: ${response.statusText}`);
+    }
+}