Refactor to use a child text node instead of a prop

vweb/esbuild.js

@@ -1,5 +1,5 @@
 require('esbuild').build({
-    entryPoints: ['src/app.js', 'src/snippet_emulator_demo.js'],
+    entryPoints: ['src/app.js', 'src/snippet_emulator_demo.jsx'],
     bundle: true,
     outdir: 'build',
     format: 'esm',

vweb/src/snippet_emulator.jsx

@@ -2,9 +2,13 @@ import './snippet_emulator.css'
 import React, {useState, useCallback, useEffect} from 'react'
 import { WasmCPU, assemble_snippet, source_map } from '../pkg/vweb.js'
 
-export default function({ snippet }) {
+export default function({ children }) {
+    if (React.Children.count(children) !== 1) {
+        throw 'Expects a single text node as a child'
+    }
+
     const [editing, setEditing] = useState(false) // Whether we're editing the snippet or running it
-    const [src, setSrc] = useState(snippet) // The source code currently set
+    const [src, setSrc] = useState('') // The source code currently set
     const [message, setMessage] = useState('') // A status / error message
     const onChangeSrc = useCallback((e) => setSrc(e.target.value), []) // Callback for the textarea
     const [binary, setBinary] = useState(null) // The assembled binary
@@ -18,15 +22,19 @@ export default function({ snippet }) {
             setBinary(bin)
             setSourceMap(sm)
             setMessage(`Assembled ${bin.length} bytes`)
-            console.log(sm.Ok)
             return true
         } catch(e) {
             setMessage(e.message)
         }
     }, [])
 
-    // On load, build the stuff
+    // On load, clean the source and build the stuff
-    useEffect(() => { rebuild(snippet) }, [snippet])
+    useEffect(() => {
+        const lines = React.Children.toArray(children)[0].split('\n')
+        const cleaned = lines.map(l => l.trim()).join('\n')
+        setSrc(cleaned)
+        rebuild(cleaned)
+    }, [rebuild, children])
 
     if (editing) {
         return (

vweb/src/snippet_emulator_demo.jsx

@@ -5,5 +5,13 @@ import init, { WasmCPU, assemble_snippet } from '../pkg/vweb.js'
 
 init().then(async () => {
     createRoot(document.getElementsByClassName('react-root')[0])
-        .render(React.createElement(SnippetEmulator, {snippet: 'push 0'}))
+        .render(
+            <SnippetEmulator>
+                {`.org 0x400
+                push 2
+                add 3
+                mul 4
+                hlt`}
+            </SnippetEmulator>
+        )
 })