create a facade over webpack, to support alternative compilers

src/core/create_compilers.ts

@@ -1,29 +1,98 @@
+import * as fs from 'fs';
 import * as path from 'path';
 import relative from 'require-relative';
 
-export default function create_compilers({ webpack }: { webpack: string }) {
-	const wp = relative('webpack', process.cwd());
+let r: any;
+let wp: any;
 
-	const serviceworker_config = try_require(path.resolve(`${webpack}/service-worker.config.js`));
+export class WebpackCompiler {
+	_: any;
 
-	return {
-		client: wp(
-			require(path.resolve(`${webpack}/client.config.js`))
-		),
+	constructor(config: any) {
+		this._ = wp(require(path.resolve(config)));
+	}
 
-		server: wp(
-			require(path.resolve(`${webpack}/server.config.js`))
-		),
+	oninvalid(cb: (filename: string) => void) {
+		this._.hooks.invalid.tap('sapper', cb);
+	}
 
-		serviceworker: serviceworker_config && wp(serviceworker_config)
-	};
+	compile() {
+		return new Promise((fulfil, reject) => {
+			this._.run((err: Error, stats: any) => {
+				if (err) {
+					reject(err);
+					process.exit(1);
+				}
+
+				if (stats.hasErrors()) {
+					console.error(stats.toString({ colors: true }));
+					reject(new Error(`Encountered errors while building app`));
+				}
+
+				else {
+					fulfil(stats);
+				}
+			});
+		});
+	}
+
+	watch(cb: (err: Error, stats: any) => void) {
+		this._.watch({}, cb);
+	}
 }
 
-function try_require(specifier: string) {
-	try {
-		return require(specifier);
-	} catch (err) {
-		if (err.code === 'MODULE_NOT_FOUND') return null;
-		throw err;
+export class RollupCompiler {
+	constructor(config: any) {
+
 	}
+
+	oninvalid(cb: (filename: string) => void) {
+
+	}
+
+	compile() {
+		return new Promise((fulfil, reject) => {
+
+		});
+	}
+
+	watch(cb: (err: Error, stats: any) => void) {
+
+	}
+}
+
+export type Compiler = RollupCompiler | WebpackCompiler;
+
+export type Compilers = {
+	client: Compiler;
+	server: Compiler;
+	serviceworker?: Compiler;
+}
+
+export default function create_compilers({ webpack, rollup }: { webpack: string, rollup: string }): Compilers {
+	if (fs.existsSync(rollup)) {
+		if (!r) r = relative('rollup', process.cwd());
+
+		const sw = `${rollup}/service-worker.config.js`;
+
+		return {
+			client: new RollupCompiler(`${rollup}/client.config.js`),
+			server: new RollupCompiler(`${rollup}/server.config.js`),
+			serviceworker: fs.existsSync(sw) && new RollupCompiler(sw)
+		};
+	}
+
+	if (fs.existsSync(webpack)) {
+		if (!wp) wp = relative('webpack', process.cwd());
+
+		const sw = `${webpack}/service-worker.config.js`;
+
+		return {
+			client: new WebpackCompiler(`${webpack}/client.config.js`),
+			server: new WebpackCompiler(`${webpack}/server.config.js`),
+			serviceworker: fs.existsSync(sw) && new WebpackCompiler(sw)
+		};
+	}
+
+	throw new Error(`Could not find config files for rollup or webpack`);
 }