Simple HMR with Jte and Ktor

hmr.js

new EventSource("/hmr").onmessage = (event) => location.reload()

Jte.kt

import gg.jte.ContentType
import gg.jte.TemplateEngine
import gg.jte.resolve.DirectoryCodeResolver
import gg.jte.watcher.DirectoryWatcher
import io.ktor.server.application.*
import io.ktor.server.jte.*
import io.ktor.server.routing.*
import io.ktor.server.sse.*
import java.nio.file.Path

fun Application.configureJte() {
    val resolver = DirectoryCodeResolver(Path.of("src/main/jte"))
    val templateEngine = TemplateEngine.create(resolver, ContentType.Html)
    val watcher = DirectoryWatcher(templateEngine, resolver)
    var shouldReload = false
    
    watcher.start {
        shouldReload = true
    }

    install(Jte) {
        this.templateEngine = templateEngine
    }

    routing {
        sse("/hmr") {
            while (!shouldReload) {
                // wait...
            }

            send("hmr", "message")
            shouldReload = false
        }
    }
}