steal-tools/lib/bundle/shim.js

Futuristic build tools for ES6 Module applications.

function(exports, global, doEval){ // jshint ignore:line
	var origDefine = global.define;

	var get = function(name){
		var parts = name.split("."),
			cur = global,
			i;
		for(i = 0 ; i < parts.length; i++){
			if(!cur) {
				break;
			}
			cur = cur[parts[i]];
		}
		return cur;
	};
	var set = function(name, val){
		var parts = name.split("."),
			cur = global,
			i, part, next;
		for(i = 0; i < parts.length - 1; i++) {
			part = parts[i];
			next = cur[part];
			if(!next) {
				next = cur[part] = {};
			}
			cur = next;
		}
		part = parts[parts.length - 1];
		cur[part] = val;
	};
	var useDefault = function(mod){
		if(!mod || !mod.__esModule) return false;
		var esProps = { __esModule: true, "default": true };
		for(var p in mod) {
			if(!esProps[p]) return false;
		}
		return true;
	};

	var hasCjsDependencies = function(deps) {
		return (
			deps[0] === "require" &&
			deps[1] === "exports" &&
			deps[2] === "module"
		);
	};

	var modules = (global.define && global.define.modules) ||
		(global._define && global._define.modules) || {};
	var ourDefine = global.define = function(moduleName, deps, callback){
		var module;
		if(typeof deps === "function") {
			callback = deps;
			deps = [];
		}
		var args = [],
			i;
		for(i =0; i < deps.length; i++) {
			args.push( exports[deps[i]] ? get(exports[deps[i]]) : ( modules[deps[i]] || get(deps[i]) )  );
		}
		// CJS has no dependencies but 3 callback arguments
		if (hasCjsDependencies(deps) || (!deps.length && callback.length)) {
			module = { exports: {} };
			args[0] = function(name) {
				return exports[name] ? get(exports[name]) : modules[name];
			};
			args[1] = module.exports;
			args[2] = module;
		}
		// Babel uses the exports and module object.
		else if(!args[0] && deps[0] === "exports") {
			module = { exports: {} };
			args[0] = module.exports;
			if(deps[1] === "module") {
				args[1] = module;
			}
		} else if(!args[0] && deps[0] === "module") {
			args[0] = { id: moduleName };
		}

		global.define = origDefine;
		var result = callback ? callback.apply(null, args) : undefined;
		global.define = ourDefine;

		// Favor CJS module.exports over the return value
		result = module && module.exports ? module.exports : result;
		modules[moduleName] = result;

		// Set global exports
		var globalExport = exports[moduleName];
		if(globalExport && !get(globalExport)) {
			if(useDefault(result)) {
				result = result["default"];
			}
			set(globalExport, result);
		}
	};
	global.define.orig = origDefine;
	global.define.modules = modules;
	global.define.amd = true;
	ourDefine("@loader", [], function(){
		// shim for @@global-helpers
		var noop = function(){};
		return {
			get: function(){
				return { prepareGlobal: noop, retrieveGlobal: noop };
			},
			global: global,
			__exec: function(__load){
				doEval(__load.source, global);
			}
		};
	});
}