CSS extraction and code-splitting

closes #388

src/core/create_compilers/RollupCompiler.ts

@@ -0,0 +1,160 @@
+import * as path from 'path';
+import relative from 'require-relative';
+import { CompileResult } from './interfaces';
+import RollupResult from './RollupResult';
+
+let rollup: any;
+
+export default class RollupCompiler {
+	_: Promise<any>;
+	_oninvalid: (filename: string) => void;
+	_start: number;
+	input: string;
+	warnings: any[];
+	errors: any[];
+	chunks: any[];
+	css_files: Array<{ id: string, code: string }>;
+
+	constructor(config: string) {
+		this._ = this.get_config(path.resolve(config));
+		this.input = null;
+		this.warnings = [];
+		this.errors = [];
+		this.chunks = [];
+		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];
+
+		(mod.plugins || (mod.plugins = [])).push({
+			name: 'sapper-internal',
+			options: (opts: any) => {
+				this.input = opts.input;
+			},
+			renderChunk: (code: string, chunk: any) => {
+				this.chunks.push(chunk);
+			},
+			transform: (code: string, id: string) => {
+				if (/\.css$/.test(id)) {
+					this.css_files.push({ id, code });
+					return ``;
+				}
+			}
+		});
+
+		const onwarn = mod.onwarn || ((warning: any, handler: (warning: any) => void) => {
+			handler(warning);
+		});
+
+		mod.onwarn = (warning: any) => {
+			onwarn(warning, (warning: any) => {
+				this.warnings.push(warning);
+			});
+		};
+
+		return mod;
+	}
+
+	oninvalid(cb: (filename: string) => void) {
+		this._oninvalid = cb;
+	}
+
+	async compile(): Promise<CompileResult> {
+		const config = await this._;
+
+		const start = Date.now();
+
+		try {
+			const bundle = await rollup.rollup(config);
+			await bundle.write(config.output);
+
+			return new RollupResult(Date.now() - start, this);
+		} catch (err) {
+			if (err.filename) {
+				// TODO this is a bit messy. Also, can
+				// Rollup emit other kinds of error?
+				err.message = [
+					`Failed to build — error in ${err.filename}: ${err.message}`,
+					err.frame
+				].filter(Boolean).join('\n');
+			}
+
+			throw err;
+		}
+	}
+
+	async watch(cb: (err?: Error, stats?: any) => void) {
+		const config = await this._;
+
+		const watcher = rollup.watch(config);
+
+		watcher.on('change', (id: string) => {
+			this.chunks = [];
+			this.warnings = [];
+			this.errors = [];
+			this._oninvalid(id);
+		});
+
+		watcher.on('event', (event: any) => {
+			switch (event.code) {
+				case 'FATAL':
+					// TODO kill the process?
+					if (event.error.filename) {
+						// TODO this is a bit messy. Also, can
+						// Rollup emit other kinds of error?
+						event.error.message = [
+							`Failed to build — error in ${event.error.filename}: ${event.error.message}`,
+							event.error.frame
+						].filter(Boolean).join('\n');
+					}
+
+					cb(event.error);
+					break;
+
+				case 'ERROR':
+					this.errors.push(event.error);
+					cb(null, new RollupResult(Date.now() - this._start, this));
+					break;
+
+				case 'START':
+				case 'END':
+					// TODO is there anything to do with this info?
+					break;
+
+				case 'BUNDLE_START':
+					this._start = Date.now();
+					break;
+
+				case 'BUNDLE_END':
+					cb(null, new RollupResult(Date.now() - this._start, this));
+					break;
+
+				default:
+					console.log(`Unexpected event ${event.code}`);
+			}
+		});
+	}
+}