feat: ensure global resolves in strict mode

If CJS is bundled into ESM, then strict mode is forced.
This patch ensures that global is resolved properly in such case

Fixes #86

Thanks @mathiasbynens for hint on CSP safe global resolution

global.js

@@ -1,5 +1,15 @@
-/* eslint strict: "off" */
-
 module.exports = (function () {
-	return this;
-}());
+	if (this) return this;
+
+	// Unexpected strict mode (may happen if e.g. bundled into ESM module) be nice
+
+	// Thanks @mathiasbynens -> https://mathiasbynens.be/notes/globalthis
+	// In all ES5 engines global object inherits from Object.prototype
+	// (if you approached one that doesn't please report)
+	Object.defineProperty(Object.prototype, "__global__", {
+		get: function () { return this; },
+		configurable: true
+	});
+	try { return __global__; }
+	finally { delete Object.prototype.__global__; }
+})();

package.json

@@ -58,7 +58,18 @@
 		"root": true,
 		"rules": {
 			"no-extend-native": "off"
-		}
+		},
+		"overrides": [
+			{
+				"files": "global.js",
+				"globals": {
+					"__global__": true
+				},
+				"rules": {
+					"strict": "off"
+				}
+			}
+		]
 	},
 	"scripts": {
 		"lint": "eslint --ignore-path=.gitignore .",

test/global.js

@@ -3,4 +3,5 @@
 module.exports = function (t, a) {
 	a.ok(t && typeof t === "object");
 	a(typeof t.Array, "function");
+	a("__global__" in Object.prototype, false);
 };