What does eval do?

[guppy0356]

I started the development server with:

pnpm react-server ./App.jsx --eval App

// App.jsx
export function App() {
  return <h1>Hello World</h1>
}

I had this error messages 🤔 I need some example codes 🐱

3:06:55 [react-server] App is not defined
3:06:55 [react-server]   [stack]: ReferenceError: App is not defined
3:06:55 [react-server]     at /Users/path/to/hello-react-server/virtual:react-server-eval.jsx/virtual:react-server-eval.jsx:1:1
3:06:55 [react-server]     at ESModulesEvaluator.runInlinedModule (file:///Users/path/to/hello-react-server/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected][email protected]/node_modules/vite/dist/node/module-runner.js:1057:6)
3:06:55 [react-server]     at RSCModuleRunner.directRequest (file:///Users/path/to/hello-react-server/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected][email protected]/node_modules/vite/dist/node/module-runner.js:1271:82)
3:06:55 [react-server]     at RSCModuleRunner.cachedRequest (file:///Users/path/to/hello-react-server/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected][email protected]/node_modules/vite/dist/node/module-runner.js:1166:28)
3:06:55 [react-server]     at RSCModuleRunner.import (file:///Users/path/to/hello-react-server/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected][email protected]/node_modules/vite/dist/node/module-runner.js:1104:23)
3:06:55 [react-server]     at RSCModuleRunner.import (file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]_@[email protected]_r_0eae41b5578d00849c4e5d77b4adca02/node_modules/@lazarv/react-server/lib/dev/create-server.mjs:383:16)
3:06:55 [react-server]     at async Promise.all (index 1)
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]_@[email protected]_r_0eae41b5578d00849c4e5d77b4adca02/node_modules/@lazarv/react-server/lib/dev/ssr-handler.mjs:104:19
3:06:55 [react-server]   [message]: App is not defined
3:06:55 [react-server] getContext(...) is not a function
3:06:55 [react-server]   [stack]: TypeError: getContext(...) is not a function
3:06:55 [react-server]     at errorHandler (file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]_@[email protected]_r_0eae41b5578d00849c4e5d77b4adca02/node_modules/@lazarv/react-server/lib/handlers/error.mjs:168:36)
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/compose/dist/index.js:39:16
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/compose/dist/index.js:12:24
3:06:55 [react-server]     at serializeCookie (file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/cookie/dist/chunk-7YVC6JWC.js:25:22)
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/compose/dist/index.js:39:16
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/compose/dist/index.js:12:24
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/compose/dist/index.js:39:16
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/compose/dist/index.js:12:24
3:06:55 [react-server]     at file:///Users/path/to/hello-react-server/node_modules/.pnpm/@[email protected]/node_modules/@hattip/adapter-node/dist/chunk-NY3T7LPC.js:68:22
3:06:55 [react-server]   [message]: getContext(...) is not a function

[lazarv]

Hi @guppy0356!

react-server --eval or react-server -e is exactly like node -e. This means that the argument contains the entry point code:

npx @lazarv/react-server -e 'export default function App(){ return <h1>Hello World</h1>; }'

Also you can use any input from stdin as the entry point code like:

curl https://gist.githubusercontent.com/lazarv/23ea9a77f7061f3086a7516d3e7edd2d/raw/4b621ea2a17fefcb9b690edd7edf57393a5da03f/App.jsx | npx @lazarv/react-server

The latter is somewhat useful, the eval argument is more like a quick and hacky way to try out some one-liner RSC idea and extends compatibility in the CLI.

[guppy0356]

Okay, I understand. Thank you for your response.