Support LAB debug output via process.env.DEBUG_LAB

Author: gigabo

packages/react-server/core/util/LAB.src.js

@@ -207,7 +207,7 @@
 		global_defaults[_AlwaysPreserveOrder] = false;
 		global_defaults[_AllowDuplicates] = false;
 		global_defaults[_CacheBust] = false;
-		/*!START_DEBUG*/global_defaults[_Debug] = false;/*!END_DEBUG*/
+		/*!START_DEBUG*/global_defaults[_Debug] = true;/*!END_DEBUG*/
 		global_defaults[_BasePath] = "";
 
 		// execute a script that has been preloaded already

packages/react-server/core/util/LABString.js

@@ -1,6 +1,18 @@
 var lab = require("fs").readFileSync(__dirname + "/LAB.src.js", "utf-8");
 
-lab = require("uglify-js").minify(lab, {fromString: true}).code;
+// Don't need this.
+lab = lab.replace(/^"use strict";/, "");
+
+// Run with `DEBUG_LAB=true` to see its output in console.log.
+if (!process.env.DEBUG_LAB) {
+
+	// This is exactly what @getify does to remove debug code.
+	// https://github.com/getify/LABjs/blob/master/BUILD.md
+	lab = lab.replace(/\/\*!START_DEBUG(?:.|[\n\r])*?END_DEBUG\*\//g, "");
+
+	// After the debug code is removed just uglify.
+	lab = require("uglify-js").minify(lab, {fromString: true}).code;
+}
 
 module.exports = `
 /*! LAB.js (LABjs :: Loading And Blocking JavaScript)