diff --git a/scripts/generate-data.js b/scripts/generate-data.js
index c50f089..51e62dc 100644
--- a/scripts/generate-data.js
+++ b/scripts/generate-data.js
@@ -2,7 +2,6 @@
 
 const resources = require('../data/resources.js');
 const generateData = require('../index.js');
-const utils = require('../scripts/utils.js');
 
 // -----------------------------------------------------------------------------
 
@@ -28,7 +27,9 @@ const complicatedWorkThatTakesTime = (resource, callback) => {
 		console.log('[%s] Worker %d \u2192 Unicode v%s',
 			getTime(), cluster.worker.id, version);
 
+		console.groupCollapsed();
 		generateData(version);
+		console.groupEnd();
 
 		complicatedWorkThatTakesTime(
 			resource.slice(1),
@@ -40,10 +41,16 @@ const complicatedWorkThatTakesTime = (resource, callback) => {
 	}
 };
 
-if (cluster.isMaster) {
+if (cluster.isPrimary) {
 
 	for (let index = 0; index < numCPUs; index++) {
-		cluster.fork();
+		const worker = cluster.fork();
+		worker.on('message', (error) => {
+			for (const id in cluster.workers) {
+				cluster.workers[id].kill();
+			}
+			throw new Error(`Worker ${worker.id} encountered an error: ${error}`);
+		})
 	}
 
 	cluster.on('online', (worker) => {
@@ -76,4 +83,14 @@ if (cluster.isMaster) {
 		});
 	});
 
+	process.on('uncaughtException', (error) => {
+		console.error(error);
+		process.send(error.message);
+	});
+
+	process.on('unhandledRejection', (error) => {
+		console.error(error);
+		process.send(error.message || error);
+	});
+
 }
diff --git a/scripts/utils.js b/scripts/utils.js
index cdd42f0..21baff8 100644
--- a/scripts/utils.js
+++ b/scripts/utils.js
@@ -11,7 +11,7 @@ const gzipInline = function(data) {
 	if (data instanceof Map) {
 		return `new Map(${ gzipInline([...data]) })`;
 	}
-	const json = jsesc(data, { 'json': true });
+	const json = JSON.stringify(data);
 	const gzipBuffer = zlib.gzipSync(json);
 	const str = gzipBuffer.toString('base64');
 	return `JSON.parse(require('zlib').gunzipSync(Buffer.from('${ str }','base64')))`;
@@ -84,7 +84,13 @@ const writeFiles = function(options) {
 		return;
 	}
 	const dirMap = {};
-	const bidiMirroringGlyphMap = [];
+	/**
+	 * A list of flatten (x, y) pairs,
+	 * where x is a codepoint, y := codepoint(z) - x,
+	 * where z is the BidiMirroringGlyph of character(x) and codepoint(z) > x
+	 * @type number[]
+	 */
+	const bidiMirroringGlyphFlatPairs = [];
 	const auxMap = {};
 	Object.keys(map).forEach(function(item) {
 		const codePoints = map[item];
@@ -112,10 +118,11 @@ const writeFiles = function(options) {
 			)
 		) {
 			if (type == 'Bidi_Mirroring_Glyph') {
-				const shortName = item.codePointAt(0);
+				const toCodepoint = item.codePointAt(0);
 				codePoints.toArray().forEach(function(codePoint) {
-					console.assert(!bidiMirroringGlyphMap[codePoint]);
-					bidiMirroringGlyphMap[codePoint] = shortName;
+					if (codePoint < toCodepoint) {
+						bidiMirroringGlyphFlatPairs.push(codePoint, toCodepoint - codePoint);
+					}
 				});
 			} else {
 				if (!auxMap[type]) {
@@ -124,34 +131,7 @@ const writeFiles = function(options) {
 				auxMap[type].push([item, codePoints]);
 			}
 		}
-		if (isNamesCanon) {
-			return;
-		}
-
-		if (type == 'Bidi_Mirroring_Glyph') {
-			const dir = path.resolve(
-				__dirname, '..',
-				'output', 'unicode-' + version, type
-			);
-			if (!hasKey(dirMap, type)) {
-				dirMap[type] = [];
-			}
-			fs.mkdirSync(dir, { recursive: true });
-			// `Bidi_Mirroring_Glyph/index.js`
-			// Note: `Bidi_Mirroring_Glyph` doesn’t have repeated strings; don’t gzip.
-			const flatPairs = bidiMirroringGlyphMap
-				.flatMap((a, b) => a < b ? [a, b - a] : []);
-			const output = [
-				`const chr=String.fromCodePoint`,
-				`const pair=(t,u,v)=>[t?u+v:v,chr(t?u:u+v)]`,
-				`module.exports=new Map(${
-					jsesc(flatPairs)
-				}.map((v,i,a)=>pair(i&1,a[i^1],v)))`
-			].join(';');
-			fs.writeFileSync(
-				path.resolve(dir, 'index.js'),
-				output
-			);
+		if (isNamesCanon || type == 'Bidi_Mirroring_Glyph') {
 			return;
 		}
 
@@ -211,6 +191,31 @@ const writeFiles = function(options) {
 			`module.exports=${ symbolsExports }`
 		);
 	});
+	if (options.type == 'Bidi_Mirroring_Glyph') {
+		const type = options.type;
+		const dir = path.resolve(
+			__dirname, '..',
+			'output', 'unicode-' + version, type
+		);
+		if (!hasKey(dirMap, type)) {
+			dirMap[type] = [];
+		}
+		fs.mkdirSync(dir, { recursive: true });
+		// `Bidi_Mirroring_Glyph/index.js`
+		// Note: `Bidi_Mirroring_Glyph` doesn’t have repeated strings; don’t gzip.
+		const output = [
+			`const chr=String.fromCodePoint`,
+			`const pair=(t,u,v)=>[t?u+v:v,chr(t?u:u+v)]`,
+			`module.exports=new Map(${
+				JSON.stringify(bidiMirroringGlyphFlatPairs)
+			}.map((v,i,a)=>pair(i&1,a[i^1],v)))`
+		].join(';');
+		fs.writeFileSync(
+			path.resolve(dir, 'index.js'),
+			output
+		);
+		return;
+	}
 	Object.keys(auxMap).forEach(function(type) {
 		const dir = path.resolve(
 			__dirname, '..',