Edge case fix for prerender errors

src/lib/webpack/prerender.js

@@ -40,35 +40,61 @@ export default function prerender(env, params) {
 const handlePrerenderError = (err, env, stack, entry) => {
 	let errorMessage = err.toString();
 	let isReferenceError =  errorMessage.startsWith('ReferenceError');
-	let sourceMapContent = JSON.parse(fs.readFileSync(`${entry}.map`));
-	let sourceMapConsumer = new SourceMapConsumer(sourceMapContent);
-	let position = sourceMapConsumer.originalPositionFor({
-		line: stack.getLineNumber(),
-		column: stack.getColumnNumber()
-	});
+	let methodName = stack.getMethodName();
+	let sourceMapContent, position, sourcePath, sourceLines, sourceCodeHighlight;
 
-	position.source = position.source.replace('webpack://', '.');
+	try {
+		sourceMapContent = JSON.parse(fs.readFileSync(`${entry}.map`));
+	} catch (err) {
+		process.stderr.write(chalk.red(`Unable to read sourcemap: ${entry}.map\n`));
+	}
 
-	let sourcePath = resolve(env.src, position.source);
-	let sourceLines = fs.readFileSync(sourcePath, 'utf-8').split('\n');
-	let methodName = stack.getMethodName();
-	let sourceCodeHighlight = '';
+	if (sourceMapContent) {
+		let sourceMapConsumer = new SourceMapConsumer(sourceMapContent);
+		position = sourceMapConsumer.originalPositionFor({
+			line: stack.getLineNumber(),
+			column: stack.getColumnNumber()
+		});
+
+		position.source = position.source.replace('webpack://', '.').replace(/^.*~\/((?:@[^/]+\/)?[^/]+)/, (s, name) => require.resolve(name).replace(/^(.*?\/node_modules\/(@[^/]+\/)?[^/]+)(\/.*)$/, '$1') );
 
-	for (var i = -4; i <= 4; i++) {
-		let color = i === 0 ? chalk.red : chalk.yellow;
-		let line = position.line + i;
-		let sourceLine = sourceLines[line - 1];
-		sourceCodeHighlight += sourceLine ? `${color(sourceLine)}\n` : '';
+		sourcePath = resolve(env.src, position.source);
+		sourceLines;
+		try {
+			sourceLines = fs.readFileSync(sourcePath, 'utf-8').split('\n');
+		} catch (err) {
+			try {
+				sourceLines = fs.readFileSync(require.resolve(position.source), 'utf-8').split('\n');
+			} catch (err) {
+				process.stderr.write(chalk.red(`Unable to read file: ${sourcePath}\n`));
+			}
+			// process.stderr.write(chalk.red(`Unable to read file: ${sourcePath}\n`));
+		}
+		sourceCodeHighlight = '';
+
+		if (sourceLines) {
+			for (var i = -4; i <= 4; i++) {
+				let color = i === 0 ? chalk.red : chalk.yellow;
+				let line = position.line + i;
+				let sourceLine = sourceLines[line - 1];
+				sourceCodeHighlight += sourceLine ? `${color(sourceLine)}\n` : '';
+			}
+		}
 	}
 
 	process.stderr.write('\n');
 	process.stderr.write(chalk.red(`${errorMessage}\n`));
 	process.stderr.write(`method: ${methodName}\n`);
-	process.stderr.write(`at: ${sourcePath}:${position.line}:${position.column}\n`);
-	process.stderr.write('\n');
-	process.stderr.write('Source code:\n\n');
-	process.stderr.write(sourceCodeHighlight);
-	process.stderr.write('\n');
+	if (sourceMapContent) {
+		process.stderr.write(`at: ${sourcePath}:${position.line}:${position.column}\n`);
+		process.stderr.write('\n');
+		process.stderr.write('Source code:\n\n');
+		process.stderr.write(sourceCodeHighlight);
+		process.stderr.write('\n');
+	}
+	else {
+		process.stderr.write(stack.toString()+'\n');
+	}
 	process.stderr.write(`This ${isReferenceError ? 'is most likely' : 'could be'} caused by using DOM or Web APIs.\n`);
 	process.stderr.write(`Pre-render runs in node and has no access to globals available in browsers.\n\n`);
 	process.stderr.write(`Consider wrapping code producing error in: 'if (typeof window !== "undefined") { ... }'\n`);

src/lib/webpack/webpack-base-config.js

@@ -62,7 +62,7 @@ export default (env) => {
 					'node_modules',
 					resolve(__dirname, '../../../node_modules')
 				],
-				extensions: ['.js', '.jsx', '.ts', '.tsx', '.json', '.less', '.scss', '.sass', '.styl','.css'],
+				extensions: ['.js', '.jsx', '.ts', '.tsx', '.json', '.less', '.scss', '.sass', '.styl', '.css'],
 				alias: {
 					'preact-cli-entrypoint': src('index.js'),
 					style: src('style'),

src/lib/webpack/webpack-client-config.js

@@ -222,7 +222,11 @@ const htmlPlugin = (config, src) => {
 		excludeAssets: [/(bundle|polyfills)(\..*)?\.js$/],
 		config,
 		ssr(params) {
-			return config.prerender ? prerender({ dest: config.dest, src }, { ...params, url }) : '';
+			return config.prerender ? prerender({
+				dest: config.dest,
+				src,
+				cwd: config.cwd
+			}, { ...params, url }) : '';
 		}
 	});
 	const pages = readJson(resolve(config.cwd, config.prerenderUrls || '')) || [{ url: "/" }];