Using PGlite or DuckDB-Wasm in the main process breaks building the main target

[noncom]

Pre-flight checklist

• I have read the contribution documentation for this project.
• I agree to follow the code of conduct that this project uses.
• I have searched the issue tracker for a bug that matches the one I want to file, without success.

Forge version

7.11.1

Electron version

40.6.1

Operating system

Windows 10

Last known working Forge version

No response

Expected behavior

Requiring and using PGlite or DuckDB-Wasm in the main process of Electron should not hang on Building src/main.ts target forever.

Using PGlite or DuckDB-Wasm databases in the main process should be possible.

Actual behavior

The Building src/main.ts target never ends:

✔ Checking your system
✔ Locating application
✔ Loading configuration
✔ Preparing native dependencies [1s]
✔ Running generateAssets hook
❯ Running preStart hook
❯ [plugin-vite] Preparing Vite bundles
✔ Launched Vite dev servers for renderer process code [0.1s]
✔ Target main_window
› ➜ Local: http://localhost:5173/
➜ Network: use --host to expose
❯ Built main process and preload bundles
⠇ Building src/main.ts target
✔ Building src/preload.ts target

Steps to reproduce

Create a fresh Electron Forge project with

npx create-electron-app@latest my-app --template=vite-typescript

Make the following changes in project configs to allow for top-level await:

// In package.json
"type": "module"

// In tsconfig.json
"compilerOptions": {
    "target": "esnext",
    "module": "esnext",
...
}

Install PGlite:

npm install @electric-sql/pglite

Add the following code from PGlite quickstart:

//In main.ts

import { PGlite } from '@electric-sql/pglite'
const db = new PGlite()

await db.exec(`
  CREATE TABLE IF NOT EXISTS todo (
    id SERIAL PRIMARY KEY,
    task TEXT,
    done BOOLEAN DEFAULT false
  );
  INSERT INTO todo (task, done) VALUES ('Install PGlite from NPM', true);
  INSERT INTO todo (task, done) VALUES ('Load PGlite', true);
  INSERT INTO todo (task, done) VALUES ('Create a table', true);
  INSERT INTO todo (task, done) VALUES ('Insert some data', true);
  INSERT INTO todo (task) VALUES ('Update a task');
`)

const ret = await db.query(`
  SELECT * from todo WHERE id = 1;
`)
console.log(ret.rows)

Run

npm run start

Witness the process hanging forever on ⠼ Building src/main.ts target.

The same problem can be repeted for DuckDB-Wasm, but they have more ways of configuring the DB in their quickstart, I won't copy them here, but I tried all of them.

Additional information

Debug output:

PS D:\path\project> npm run start

> project@1.0.0 start
> electron-forge start

❯ Checking your system
  electron-forge:check-system checking system, create ~/.skip-forge-system-check to stop doing this +0ms
❯ Checking package manager version
  electron-forge:package-manager Resolved package manager to npm. (Derived from NODE_INSTALLER: undefined, npm_config_user_agent: npm/11.4.1 node/v22.14.0 win32 x64 workspaces/false, lockfile: npm) +0ms
✔ Found npm@11.4.1
✔ Checking your system
❯ Locating application
  electron-forge:project-resolver searching for project in: D:\path\project +0ms
  electron-forge:project-resolver package.json with forge dependency found in D:\path\project\package.json +2ms
✔ Locating application
❯ Loading configuration
  electron-forge:plugin:vite hooking process events +0ms
✔ Loading configuration
❯ Preparing native dependencies
✔ Preparing native dependencies
❯ Running generateAssets hook
✔ Running generateAssets hook
❯ Running preStart hook
❯ [plugin-vite] Preparing Vite bundles
  electron-forge:plugin:vite preStart: removing old content from D:\path\project\.vite +1s
❯ Launching Vite dev servers for renderer process code...
❯ Target main_window
Port 5173 is in use, trying another one...
›   ➜  Local:   http://localhost:5174/  
➜  Network: use --host to expose
✔ Target main_window
✔ Launched Vite dev servers for renderer process code
❯ Building main process and preload bundles...
❯ Building src/main.ts target
❯ Building src/preload.ts target
Generated an empty chunk: "preload".
16:33:26 [@electron-forge/plugin-vite] target built src/preload.ts
  electron-forge:plugin:vite no error in buildEnd and reached closeBundle so build succeeded +519ms
✔ Building src/preload.ts target
node_modules/@electric-sql/pglite/dist/index.js (1:11906070): Use of eval in "node_modules/@electric-sql/pglite/dist/index.js" is strongly discouraged as it poses security risks and may cause issues with minification.
node_modules/@electric-sql/pglite/dist/index.js (1:11906548): Use of eval in "node_modules/@electric-sql/pglite/dist/index.js" is strongly discouraged as it poses security risks and may cause issues with minification.

16:33:28 Module format "cjs" does not support top-level await. Use the "es" or "system" output formats rather.
file: D:/path/project/src/main.ts

[noncom]

I just realized that there's probably two problems at once. I'm new to this ecosystem, so I got confused a bit.

The problem that Electron debug prints out, Module format "cjs" does not support top-level await. Use the "es" or "system" output formats rather in the log above seems to be #3943. I haven't seen this message prior to enabling debug which was suggested when I was already creating the ticket.

But also there's another problem covered by it. If I remove all the added code, and only keep this:

import { PGlite } from '@electric-sql/pglite'
const db = new PGlite()

then it does start with debug enabled, but there are different errors in the log, see at the bottom:

PS D:\path\project> npm run start

> project@1.0.0 start
> electron-forge start

❯ Checking your system
  electron-forge:check-system checking system, create ~/.skip-forge-system-check to stop doing this +0ms
❯ Checking package manager version
  electron-forge:package-manager Resolved package manager to npm. (Derived from NODE_INSTALLER: undefined, npm_config_user_agent: npm/11.4.1 node/v22.14.0 win32 x64 workspaces/false, lockfile: npm) +0ms
✔ Found npm@11.4.1
✔ Checking your system
❯ Locating application
  electron-forge:project-resolver searching for project in: D:\path\project +0ms
  electron-forge:project-resolver package.json with forge dependency found in D:\path\project\package.json +2ms
✔ Locating application
❯ Loading configuration
  electron-forge:plugin:vite hooking process events +0ms
✔ Loading configuration
❯ Preparing native dependencies
✔ Preparing native dependencies
❯ Running generateAssets hook
✔ Running generateAssets hook
❯ Running preStart hook
❯ [plugin-vite] Preparing Vite bundles
  electron-forge:plugin:vite preStart: removing old content from D:\path\project\.vite +1s
❯ Launching Vite dev servers for renderer process code...
❯ Target main_window
Port 5173 is in use, trying another one...
›   ➜  Local:   http://localhost:5174/  
➜  Network: use --host to expose
✔ Target main_window
✔ Launched Vite dev servers for renderer process code
❯ Building main process and preload bundles...
❯ Building src/main.ts target
❯ Building src/preload.ts target
Generated an empty chunk: "preload".
16:44:48 [@electron-forge/plugin-vite] target built src/preload.ts
  electron-forge:plugin:vite no error in buildEnd and reached closeBundle so build succeeded +505ms
✔ Building src/preload.ts target
node_modules/@electric-sql/pglite/dist/index.js (1:11906070): Use of eval in "node_modules/@electric-sql/pglite/dist/index.js" is strongly discouraged as it poses security risks and may cause issues with minification.
node_modules/@electric-sql/pglite/dist/index.js (1:11906548): Use of eval in "node_modules/@electric-sql/pglite/dist/index.js" is strongly discouraged as it poses security risks and may cause issues with minification.
16:44:50 [@electron-forge/plugin-vite] target built src/main.ts
  electron-forge:plugin:vite no error in buildEnd and reached closeBundle so build succeeded +2s
✔ Building src/main.ts target
✔ Built main process and preload bundles
✔ [plugin-vite] Preparing Vite bundles
✔ Running preStart hook
✔ Launched Electron app. Type rs in terminal to restart main process.
  electron-forge:start Electron binary path: D:\path\project\node_modules\electron\dist\electron.exe +0ms
  electron-forge:plugin:vite hooking electron process exit +15ms


(node:42620) UnhandledPromiseRejectionWarning: TypeError [ERR_INVALID_URL_SCHEME]: The URL must be of scheme file
    at splitPath (node:electron/js2c/node_init:2:1032)
    at t.promises.readFile (node:electron/js2c/node_init:2:10800)
    at Er (D:\path\project\.vite\build\main2.cjs:904:30237257)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
(Use `electron --trace-warnings ...` to show where the warning was created)
(node:42620) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on 
unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:42620) UnhandledPromiseRejectionWarning: TypeError [ERR_INVALID_URL_SCHEME]: The URL must be of scheme file
    at splitPath (node:electron/js2c/node_init:2:1032)
    at t.promises.readFile (node:electron/js2c/node_init:2:10800)
    at Er (D:\path\project\.vite\build\main2.cjs:904:30237257)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
(node:42620) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on 
unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)

[noncom]

For anyone interested, there's a solution now, kindly provided by @UmbrellaCrow612. The PR fully explains it and fixes the problem.

Long story short, using Vite on the backend side of Electron complicates things more than it does any good, it seems.

I don't know if this can be considered solved and closed, as yes there's a way to use PGlite and Wasm in the backend, but the electron-vite template is still broken in the sense that it doesn't allow doing that. All my prior searches for any issues in using Wasm with Vite revealed a lot of various cases, but in different circumstanes, and none of the solutions worked in this case. So I would say that from my observation it is simply impossible to use the electron-vite template for apps with Wasm in the backend.