Use webRequestBlocking if built for firefox

bob.mjs

@@ -150,11 +150,17 @@ const tasks = new Listr([
     title: 'Merge manifests',
     task: (ctx) => {
       ctx.manifest = browser === 'chrome' ? manifestChrome : manifestFirefox;
+
+      // Object merge isn't deep, so manually merge permission stuff.
+      const mergedPermissions = [...manifestShared.permissions, ...ctx.manifest.permissions];
+
       // Overwrite shared settings with browser based values.
       ctx.manifest = {
         ...manifestShared,
         ...ctx.manifest,
       };
+
+      ctx.manifest.permissions = mergedPermissions;
     },
   },
   {

manifest.chrome.json

@@ -1,4 +1,5 @@
 {
+  "permissions": [],
   "background": {
     "service_worker": "src/background/main.js"
   }

manifest.firefox.json

@@ -1,4 +1,7 @@
 {
+  "permissions": [
+    "webRequestBlocking"
+  ],
   "background": {
     "scripts": [
       "src/background/main.js"

src/background/main.ts

@@ -11,6 +11,13 @@ import { setBangsLookup } from './lookup';
 import { setIgnoredDomains } from './ignoreddomains';
 import defaultSettings from '../lib/settings.default.json';
 
+function devLog(message: string): void {
+  if (dev) {
+    // eslint-disable-next-line no-console
+    console.info(message);
+  }
+}
+
 function updateGlobals(settings: Settings): void {
   setBangsLookup(settings);
   setIgnoredDomains(settings.options.ignoredDomains);
@@ -48,10 +55,7 @@ async function setupSettings(): Promise<void> {
 }
 
 function main(): void {
-  if (dev) {
-    // eslint-disable-next-line no-console
-    console.info(`Dev: ${dev}, Browser: ${currentBrowser}, Version: ${version}, Hash: ${hash}`);
-  }
+  devLog(`Dev: ${dev}, Browser: ${currentBrowser}, Version: ${version}, Hash: ${hash}`);
 
   // Because service workers need to set their event listeners immediately, we can't await this.
   // FIXME: There may be a better way to do this, but for now we just hope it runs quickly!
@@ -66,14 +70,25 @@ function main(): void {
     }
   });
 
+  // The requestBody opt is required for handling POST situations.
+  const extraInfoSpec: browser.WebRequest.OnBeforeRequestOptions[] = ['requestBody'];
+
+  // Wrap processRequest because the types don't like an async non-blocking handler.
+  let webRequestHandler = (r: browser.WebRequest.OnBeforeRequestDetailsType) => {
+    processRequest(r);
+  };
+
+  if (currentBrowser === 'firefox') {
+    devLog('Enabling blocking webRequest listener');
+    // Add blocking spec and unwrap processRequest as it may return a blocking response.
+    extraInfoSpec.push('blocking');
+    webRequestHandler = processRequest;
+  }
+
   browser.webRequest.onBeforeRequest.addListener(
-    (r) => {
-      // Type defs don't like an async non-blocking handler.
-      processRequest(r);
-    },
+    webRequestHandler,
     { urls: hostPermissions },
-    // The requestBody opt is required for handling POST situations.
-    ['requestBody'],
+    extraInfoSpec,
   );
 }
 

src/background/requests.ts

@@ -1,5 +1,6 @@
 import browser, { WebRequest } from 'webextension-polyfill';
 
+import { currentBrowser } from '../lib/esbuilddefinitions';
 import { getBangsLookup } from './lookup';
 import { getIgnoredDomains } from './ignoreddomains';
 
@@ -122,7 +123,7 @@ export async function getRedirects(
  */
 export async function processRequest(
   r: WebRequest.OnBeforeRequestDetailsType,
-): Promise<void> {
+): Promise<void | WebRequest.BlockingResponse> {
   if (r.type !== 'main_frame') {
     return Promise.resolve();
   }
@@ -143,8 +144,19 @@ export async function processRequest(
     browser.tabs.create({ url: redirections[i] });
   }
 
-  // Finally send the current tab to the first in the array.
-  browser.tabs.update(r.tabId, { url: redirections[0] });
+  if (r.method !== 'GET' || currentBrowser !== 'firefox') {
+    // If we're handling a POST request, we need to tell the tab where to go, as
+    // redirecting the POST would not change the tabs location.
+    // OR we're not using firefox, in which case we have to use this method anyway.
+    browser.tabs.update(r.tabId, { url: redirections[0] });
 
-  return Promise.resolve();
+    if (currentBrowser === 'firefox') {
+      return Promise.resolve({ cancel: true });
+    }
+
+    return Promise.resolve();
+  }
+
+  // This is a GET request, we are on firefox, so send a blocking response.
+  return Promise.resolve({ redirectUrl: redirections[0] });
 }