feat(service-preload): Embed service-inject

Embed the service-inject script into the service-preload script to avoid
having to load it manually and reduce IPC communication when a service
loads.

Signed-off-by: Kristóf Marussy <kristof@marussy.com>

1 files changed, 16 insertions, 19 deletions

diff --git a/packages/service-preload/src/index.ts b/packages/service-preload/src/index.ts
index a49a3a4..99d02ec 100644
--- a/packages/service-preload/src/index.ts
+++ b/packages/service-preload/src/index.ts
@@ -18,9 +18,10 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { ServiceToMainIpcMessage, WebSource } from '@sophie/service-shared';
 import colorString from 'color-string';
-import { ipcRenderer, webFrame } from 'electron';
+import { webFrame } from 'electron';
+// eslint-disable-next-line import/no-unresolved -- Synthetic import provided by an eslint plugin.
+import injectSource from 'sophie-src:@sophie/service-inject';
 
 const DEFAULT_BG_COLOR = '#fff';
 
@@ -79,35 +80,31 @@ if (webFrame.parent === null) {
 }
 
 /**
- * Fetches and executes the service inject script in the isolated world.
+ * Executes the service inject script in the isolated world.
  *
  * The service inject script relies on exposed APIs, so this function can only
  * be called after APIs have been exposed via `contextBridge` to the main world.
  *
- * We have to call `executeJavaScriptInIsolatedWorld` from the service preload script,
- * beause there is no way currently (electron 16) to execute a script on a
- * `WebFrameMain` in the main process by specifying a `WebSource`.
- * Calling `executeJavaScriptInInsolatedWorld` on a `WebContents` in the main process
- * will always inject the script into the _top-level_ frame, but here we
- * are injecting into the _current_ frame instead.
+ * We embed the source code of the inject script into the preload script
+ * with an esbuild plugin, so there is no need to fetch it separately.
+ *
  * As a tradeoff, the promise returned by `executeJavaScriptInIsolatedWorld`
  * will resolve to `unknown` (instead of rejecting) even if the injected script fails,
  * because chromium doesn't dispatch main world errors to isolated worlds.
  *
- * @return A promise that only rejects if we fail to fetch the inject script.
- * @see https://www.electronjs.org/docs/latest/api/web-frame#webframeexecutejavascriptinisolatedworldworldid-scripts-usergesture-callback
- * @see https://www.electronjs.org/docs/latest/api/web-frame-main#frameexecutejavascriptcode-usergesture
- * @see https://www.electronjs.org/docs/latest/api/web-contents#contentsexecutejavascriptinisolatedworldworldid-scripts-usergesture
+ * @return A promise that always resolves to `undefined`.
  */
 async function fetchAndExecuteInjectScript(): Promise<void> {
-  const apiExposedResponse: unknown = await ipcRenderer.invoke(
-    ServiceToMainIpcMessage.ApiExposedInMainWorld,
-  );
-  const injectSource = WebSource.parse(apiExposedResponse);
   // Isolated world 0 is the main world.
-  await webFrame.executeJavaScriptInIsolatedWorld(0, [injectSource]);
+  await webFrame.executeJavaScriptInIsolatedWorld(0, [
+    {
+      code: injectSource,
+    },
+  ]);
 }
 
 fetchAndExecuteInjectScript().catch((error) => {
-  console.error('Failed to fetch inject source:', error);
+  // This will never happen because of
+  // https://www.electronjs.org/docs/latest/api/web-frame#webframeexecutejavascriptinisolatedworldworldid-scripts-usergesture-callback
+  console.error('Failed to execute service inject:', error);
 });