Fix build with newer parcel-bundler

Fixes fathyb#64, fathyb#65, fathyb#59

src/frontend/assets/typescript.ts

@@ -2,49 +2,47 @@ import {Configuration, loadConfiguration} from '../../backend/config-loader'
 import {IPCClient} from '../../backend/worker/client'
 
 import {processSourceMaps} from '../../exports'
-import {JSAsset} from './js-asset'
 
-export = function MakeTranspileAsset(name: string, options: any) {
-	const {parser} = options
-	const Asset = parser.findParser('file.js') as typeof JSAsset
+import TypescriptAsset from 'parcel-bundler/src/assets/TypeScriptAsset'
 
-	return new (class TSAsset extends Asset {
-		private readonly config: Promise<Configuration>
+class TSAsset extends TypescriptAsset {
+	private readonly config: Promise<Configuration>
 
-		constructor() {
-			super(name, options)
+	constructor() {
+		super(name, options)
 
-			this.config = loadConfiguration(name, options.rootDir)
-		}
+		this.config = loadConfiguration(name, options.rootDir)
+	}
 
-		public async parse(): Promise<any> {
-			const config = await this.config
-			const reportErrors = !config.typescript.options.noEmitOnError
-			const result = await IPCClient.compile({
-				file: this.name,
-				rootDir: this.options.rootDir,
-				reportErrors
-			})
+	public async parse(): Promise<any> {
+		const config = await this.config
+		const reportErrors = !config.typescript.options.noEmitOnError
+		const result = await IPCClient.compile({
+			file: this.name,
+			rootDir: this.options.rootDir,
+			reportErrors
+		})
 
-			if(!reportErrors) {
-				const {diagnostics} = result
+		if(!reportErrors) {
+			const {diagnostics} = result
 
-				if(diagnostics) {
-					console.error(diagnostics)
+			if(diagnostics) {
+				console.error(diagnostics)
 
-					// tslint:disable:no-string-throw
-					throw 'TypeScript errors were found while compiling'
-				}
+				// tslint:disable:no-string-throw
+				throw 'TypeScript errors were found while compiling'
 			}
+		}
 
-			this.contents = processSourceMaps(this, result.sources).js
+		this.contents = processSourceMaps(this, result.sources).js
 
-			// Parse result as ast format through babylon
-			return super.parse(this.contents)
-		}
+		// Parse result as ast format through babylon
+		return super.parse(this.contents)
+	}
 
-		public generateErrorMessage(err: any) {
-			return err.stack || err.message || err
-		}
-	})()
+	public generateErrorMessage(err: any) {
+		return err.stack || err.message || err
+	}
 }
+
+export = TSAsset