Load wxt.config.ts as ESM

[aklinker1]

Describe the bug

Currently, WXT uses c12 (and c12 uses jiti internally) to load the wxt.config.ts file, but it is loaded as CJS.

This causes Vite 5's CJS warning to show up when importing a Vite plugin, like Vue. At the bottom of the stacktrace, you can see the warning is triggered by @vitejs/plugin-vue in this case. Same with all other vite plugins that import vite.

Trace: The CJS build of Vite's Node API is deprecated. See https://vitejs.dev/guide/troubleshooting.html#vite-cjs-node-api-deprecated for more details.
    at warnCjsUsage (/home/runner/work/wxt/wxt/templates/vue/node_modules/vite/index.cjs:32:3)
    at Object.<anonymous> (/home/runner/work/wxt/wxt/templates/vue/node_modules/vite/index.cjs:3:1)
    at Module._compile (node:internal/modules/cjs/loader:1356:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1414:10)
    at Module.load (node:internal/modules/cjs/loader:1197:32)
    at Module._load (node:internal/modules/cjs/loader:1013:12)
    at Module.require (node:internal/modules/cjs/loader:1225:19)
    at require (node:internal/modules/helpers:177:18)
    at Object.<anonymous> (/home/runner/work/wxt/wxt/templates/vue/node_modules/@vitejs/plugin-vue/dist/index.cjs:6:14)
    at Module._compile (node:internal/modules/cjs/loader:1356:14)

To Reproduce

repro.zip

pnpx wxt@0.12.3 init . --template vue
pnpm i
pnpm build

Note

Using v0.12.3 because the warning is silenced in later versions.

The warning is present in the prepare, build, and dev commands.

Expected behavior

The wxt.config.ts file should be imported as ESM, and these warnings should go away.

Environment

  System:
    OS: macOS 13.4.1
    CPU: (8) arm64 Apple M1 Pro
    Memory: 1.19 GB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 18.16.1 - ~/.asdf/installs/nodejs/18.16.1/bin/node
    Yarn: 1.22.19 - ~/.asdf/installs/nodejs/18.16.1/bin/yarn
    npm: 9.5.1 - ~/.asdf/plugins/nodejs/shims/npm
    pnpm: 8.9.0 - ~/.asdf/installs/nodejs/18.16.1/bin/pnpm
  Browsers:
    Chrome: 120.0.6099.129
    Safari: 16.5.2
  npmPackages:
    wxt: ^0.12.0 => 0.12.3

Additional context

• Remove Vite 5 CJS warning #277 (comment)
• Remove Vite 5 CJS warning #277 (comment)

[aklinker1]

Looks like this should be possible to do with c12 already... unjs/unbuild#94