CSS extraction and code-splitting

closes #388

src/core/create_compilers/WebpackResult.ts

@@ -0,0 +1,73 @@
+import format_messages from 'webpack-format-messages';
+import { CompileResult, BuildInfo, CompileError, Chunk, CssFile } from './interfaces';
+import { ManifestData, Dirs } from '../../interfaces';
+
+const locPattern = /\((\d+):(\d+)\)$/;
+
+function munge_warning_or_error(message: string) {
+	// TODO this is all a bit rube goldberg...
+	const lines = message.split('\n');
+
+	const file = lines.shift()
+		.replace('', '') // careful — there is a special character at the beginning of this string
+		.replace('', '')
+		.replace('./', '');
+
+	let line = null;
+	let column = null;
+
+	const match = locPattern.exec(lines[0]);
+	if (match) {
+		lines[0] = lines[0].replace(locPattern, '');
+		line = +match[1];
+		column = +match[2];
+	}
+
+	return {
+		file,
+		message: lines.join('\n')
+	};
+}
+
+export default class WebpackResult implements CompileResult {
+	duration: number;
+	errors: CompileError[];
+	warnings: CompileError[];
+	chunks: Chunk[];
+	assets: Record<string, string>;
+	css_files: CssFile[];
+	stats: any;
+
+	constructor(stats: any) {
+		this.stats = stats;
+
+		const info = stats.toJson();
+
+		const messages = format_messages(stats);
+
+		this.errors = messages.errors.map(munge_warning_or_error);
+		this.warnings = messages.warnings.map(munge_warning_or_error);
+
+		this.duration = info.time;
+
+		this.chunks = info.assets.map((chunk: { name: string }) => ({ file: chunk.name }));
+		this.assets = info.assetsByChunkName;
+	}
+
+	to_json(manifest_data: ManifestData, dirs: Dirs): BuildInfo {
+		return {
+			bundler: 'webpack',
+			shimport: null, // webpack has its own loader
+			assets: this.assets,
+			css: {
+				// TODO
+				main: null,
+				chunks: {}
+			}
+		};
+	}
+
+	print() {
+		return this.stats.toString({ colors: true });
+	}
+}