move config into single file, add errors to help people migrate

src/core/create_compilers/RollupCompiler.ts

@@ -15,8 +15,8 @@ export default class RollupCompiler {
 	chunks: any[];
 	css_files: Array<{ id: string, code: string }>;
 
-	constructor(config: string) {
-		this._ = this.get_config(path.resolve(config));
+	constructor(config: any) {
+		this._ = this.get_config(config);
 		this.input = null;
 		this.warnings = [];
 		this.errors = [];
@@ -24,31 +24,8 @@ export default class RollupCompiler {
 		this.css_files = [];
 	}
 
-	async get_config(input: string) {
-		if (!rollup) rollup = relative('rollup', process.cwd());
-
-		const bundle = await rollup.rollup({
-			input,
-			external: (id: string) => {
-				return (id[0] !== '.' && !path.isAbsolute(id)) || id.slice(-5, id.length) === '.json';
-			}
-		});
-
-		const { code } = await bundle.generate({ format: 'cjs' });
-
-		// temporarily override require
-		const defaultLoader = require.extensions['.js'];
-		require.extensions['.js'] = (module: any, filename: string) => {
-			if (filename === input) {
-				module._compile(code, filename);
-			} else {
-				defaultLoader(module, filename);
-			}
-		};
-
-		const mod: any = require(input);
-		delete require.cache[input];
-
+	async get_config(mod: any) {
+		// TODO this is hacky, and doesn't need to apply to all three compilers
 		(mod.plugins || (mod.plugins = [])).push({
 			name: 'sapper-internal',
 			options: (opts: any) => {
@@ -157,4 +134,34 @@ export default class RollupCompiler {
 			}
 		});
 	}
+
+	static async load_config() {
+		if (!rollup) rollup = relative('rollup', process.cwd());
+
+		const input = path.resolve('rollup.config.js');
+
+		const bundle = await rollup.rollup({
+			input,
+			external: (id: string) => {
+				return (id[0] !== '.' && !path.isAbsolute(id)) || id.slice(-5, id.length) === '.json';
+			}
+		});
+
+		const { code } = await bundle.generate({ format: 'cjs' });
+
+		// temporarily override require
+		const defaultLoader = require.extensions['.js'];
+		require.extensions['.js'] = (module: any, filename: string) => {
+			if (filename === input) {
+				module._compile(code, filename);
+			} else {
+				defaultLoader(module, filename);
+			}
+		};
+
+		const config: any = require(input);
+		delete require.cache[input];
+
+		return config;
+	}
 }

src/core/create_compilers/WebpackCompiler.ts

@@ -1,4 +1,3 @@
-import * as path from 'path';
 import relative from 'require-relative';
 import { CompileResult } from './interfaces';
 import WebpackResult from './WebpackResult';
@@ -8,9 +7,9 @@ let webpack: any;
 export class WebpackCompiler {
 	_: any;
 
-	constructor(config: string) {
+	constructor(config: any) {
 		if (!webpack) webpack = relative('webpack', process.cwd());
-		this._ = webpack(require(path.resolve(config)));
+		this._ = webpack(config);
 	}
 
 	oninvalid(cb: (filename: string) => void) {

src/core/create_compilers/index.ts

@@ -1,5 +1,4 @@
-import * as fs from 'fs';
-import { Dirs } from '../../interfaces';
+import * as path from 'path';
 import RollupCompiler from './RollupCompiler';
 import { WebpackCompiler } from './WebpackCompiler';
 
@@ -11,27 +10,35 @@ export type Compilers = {
 	serviceworker?: Compiler;
 }
 
-export default function create_compilers(bundler: string, dirs: Dirs): Compilers {
+export default async function create_compilers(bundler: 'rollup' | 'webpack'): Promise<Compilers> {
 	if (bundler === 'rollup') {
-		const sw = `${dirs.rollup}/service-worker.config.js`;
+		const config = await RollupCompiler.load_config();
+		validate_config(config, 'rollup');
 
 		return {
-			client: new RollupCompiler(`${dirs.rollup}/client.config.js`),
-			server: new RollupCompiler(`${dirs.rollup}/server.config.js`),
-			serviceworker: fs.existsSync(sw) && new RollupCompiler(sw)
+			client: new RollupCompiler(config.client),
+			server: new RollupCompiler(config.server),
+			serviceworker: config.serviceworker && new RollupCompiler(config.serviceworker)
 		};
 	}
 
 	if (bundler === 'webpack') {
-		const sw = `${dirs.webpack}/service-worker.config.js`;
+		const config = require(path.resolve('webpack.config.js'));
+		validate_config(config, 'webpack');
 
 		return {
-			client: new WebpackCompiler(`${dirs.webpack}/client.config.js`),
-			server: new WebpackCompiler(`${dirs.webpack}/server.config.js`),
-			serviceworker: fs.existsSync(sw) && new WebpackCompiler(sw)
+			client: new WebpackCompiler(config.client),
+			server: new WebpackCompiler(config.server),
+			serviceworker: config.serviceworker && new WebpackCompiler(config.serviceworker)
 		};
 	}
 
 	// this shouldn't be possible...
 	throw new Error(`Invalid bundler option '${bundler}'`);
+}
+
+function validate_config(config: any, bundler: 'rollup' | 'webpack') {
+	if (!config.client || !config.server) {
+		throw new Error(`${bundler}.config.js must export a { client, server, serviceworker? } object`);
+	}
 }