Merge 94ace62 into 4fbb627

index.js

@@ -1,6 +1,5 @@
 'use strict';
 
-var koalas = require('koalas');
 var normalize = require('value-or-function');
 
 var slice = Array.prototype.slice;
@@ -12,49 +11,100 @@ function createResolver(config, options) {
 
   var resolver = {
     resolve: resolve,
+    isConstant: isConstant,
   };
 
-  var lastKey;
+  // Keep constants separately
+  var constants = {};
+
+  // Keep requested keys to detect (and disallow) recursive resolution
+  var stack = [];
 
   function resolve(key) {
-    if (typeof key !== 'string') {
-      return;
-    }
 
-    var appliedArgs = slice.call(arguments, 1);
+    if (isConstant(key)) {
+      return constants[key];
+    }
 
     var definition = config[key];
     // Ignore options that are not defined
     if (!definition) {
       return;
     }
 
-    if (key === lastKey) {
+    if (stack.some(function(s) {
+      if (key === s) {
+        return true;
+      }
+    })) {
       throw new Error('Recursive resolution denied.');
     }
-    lastKey = key;
 
-    var option = options[key];
-    // Bind the option so it can resolve other options if necessary
-    if (typeof option === 'function') {
-      option = option.bind(resolver);
+    stack.push(key);
+    try {
+      var option = options[key];
+      var appliedArgs = slice.call(arguments, 1);
+      var args = [definition.type, option].concat(appliedArgs);
+
+      if (typeof option === 'function') {
+        option = normalize.apply(null, args);
+      } else {
+        option = null;
+      }
+
+      if (option === null) {
+        option = definition.default;
+        if (typeof option === 'function') {
+          option = option.apply(resolver, appliedArgs);
+        }
+      }
+
+      stack.pop();
+      return option;
+
+    } catch (err) {
+      stack.pop();
+      throw err;
     }
+  }
+
+
+  function isConstant(key) {
+    return constants.hasOwnProperty(key);
+  }
 
-    var args = [definition.type, option].concat(appliedArgs);
-    var result = normalize.apply(null, args);
+
+  // Pre-process
+  options = Object.keys(config).reduce(function(opts, key) {
+
+    var definition = config[key];
+    var option = options[key];
+
+    if (!!option || options.hasOwnProperty(key)) {
+      if (typeof option !== 'function') {
+        option = normalize.call(null, definition.type, option);
+        if (option !== null) {
+          constants[key] = option;
+          return opts;
+        }
+        // Fall through
+      } else {
+        opts[key] = option.bind(resolver);
+        return opts;
+      }
+    }
 
     var fallback = definition.default;
-    // Bind & apply the default so it can resolve other options if necessary
-    if (typeof fallback === 'function') {
-      fallback = fallback.apply(resolver, appliedArgs);
+    if (typeof fallback !== 'function') {
+      constants[key] = fallback;
     }
 
-    lastKey = null;
+    return opts;
+  }, {});
 
-    return koalas(result, fallback);
-  }
 
   return resolver;
 }
 
+
 module.exports = createResolver;

package.json

@@ -24,7 +24,6 @@
     "coveralls": "npm run cover && istanbul-coveralls"
   },
   "dependencies": {
-    "koalas": "^1.0.2",
     "value-or-function": "^2.0.0"
   },
   "devDependencies": {