Hidden envs

Author: tehsenaus

README.md

@@ -180,6 +180,30 @@ mkenv.vars(env).should.eql({ x: 'y', y: 'z'})
 ```
 
 
+## mkenv.hidden(env)
+ mkenv.hidden(env) allows values to be retrieved from the root
+
+```
+mkenv(
+	mkenv.hidden({ z: 'y' }),
+	mkenv({ 'x': '$z' })
+)('x').should.equal('y')
+```
+
+
+ mkenv.hidden(env) doesn't allow direct retrieval from the root
+
+```
+should.equal(
+	mkenv(
+		mkenv.hidden({ z: 'y' }),
+		mkenv({ 'x': '${z}' })
+	)('z'),
+	null
+)
+```
+
+
 
 
 

mkenv.js

@@ -1,15 +1,16 @@
 
-module.exports = function () {
+var mkenv = module.exports = function () {
 	var chain = [].slice.call(arguments, 0);
 
-	function eval(name, root) {
+	function eval(name, root, depth) {
 		root = root || eval;
+		depth = depth || 0;
 		try {
 			var value = null;
 			for ( var i = chain.length - 1; value === null && i >= 0; i-- ) {
 				var env = chain[i];
 				if ( typeof env === "function" && env !== eval ) {
-					value = env(name, root);
+					value = env(name, root, depth);
 				} else if ( env && env.hasOwnProperty(name) ) {
 					value = env[name];
 				}
@@ -19,7 +20,7 @@ module.exports = function () {
 
 			// Simple replacements
 			value = value.replace(/\$([a-zA-Z0-9_]+)/g, function (m, pkey) {
-				var v = root(pkey);
+				var v = root(pkey, root, depth + 1);
 				return v === null || v === undefined ? '' : v;
 			})
 
@@ -30,7 +31,7 @@ module.exports = function () {
 
 				value = value.replace(/\$\{([a-zA-Z0-9_\-\\\/]+)\}/g, function (m, pkey) {
 					numReplacements++;
-					var v = root(pkey);
+					var v = root(pkey, root, depth + 1);
 					return v === null || v === undefined ? '' : v;
 				})
 			} while (numReplacements > 0);
@@ -72,12 +73,20 @@ function getKeys(env) {
 
 	return Object.keys(keys);
 }
-module.exports.keys = getKeys;
+mkenv.keys = getKeys;
 
-module.exports.vars = function vars(env) {
+mkenv.vars = function vars(env) {
 	var vars = {};
 	getKeys(env).forEach(function (key) {
 		vars[key] = env(key);
 	});
 	return vars;
 }
+
+
+mkenv.hidden = function hidden(env) {
+	env = mkenv(env);
+	return function (key, root, depth) {
+		return depth ? env(key, root) : null;
+	}
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "mkenv",
-  "version": "1.1.1",
+  "version": "1.2.0",
   "description": "Parser/template engine for simple enviroment variable-like text replacements",
   "main": "mkenv.js",
   "scripts": {

test/mkenv.js

@@ -155,6 +155,24 @@ describe('mkenv', function () {
 		})
 	})
 
+	describe('mkenv.hidden(env)', function () {
+		it('allows values to be retrieved from the root', function () {
+			mkenv(
+				mkenv.hidden({ z: 'y' }),
+				mkenv({ 'x': '$z' })
+			)('x').should.equal('y')
+		})
+
+		it('doesn\'t allow direct retrieval from the root', function () {
+			should.equal(
+				mkenv(
+					mkenv.hidden({ z: 'y' }),
+					mkenv({ 'x': '${z}' })
+				)('z'),
+				null
+			)
+		})
+	})
 
 	docha.doc("\n\n\nDocumentation generated by [Docha](https://github.com/tehsenaus/docha)");
 });