first commit

node_modules/resolve-options/index.js

@@ -0,0 +1,111 @@
+'use strict';
+
+var normalize = require('value-or-function');
+
+var slice = Array.prototype.slice;
+
+function createResolver(config, options) {
+  // TODO: should the config object be validated?
+  config = config || {};
+  options = options || {};
+
+  var resolver = {
+    resolve: resolve,
+  };
+
+
+  // Keep constants separately
+  var constants = {};
+
+  function resolveConstant(key) {
+    if (constants.hasOwnProperty(key)) {
+      return constants[key];
+    }
+
+    var definition = config[key];
+    // Ignore options that are not defined
+    if (!definition) {
+      return;
+    }
+
+    var option = options[key];
+
+    if (option != null) {
+      if (typeof option === 'function') {
+        return;
+      }
+      option = normalize.call(resolver, definition.type, option);
+      if (option != null) {
+        constants[key] = option;
+        return option;
+      }
+    }
+
+    var fallback = definition.default;
+    if (option == null && typeof fallback !== 'function') {
+      constants[key] = fallback;
+      return fallback;
+    }
+  }
+
+
+  // Keep requested keys to detect (and disallow) recursive resolution
+  var stack = [];
+
+  function resolve(key) {
+    var option = resolveConstant(key);
+    if (option != null) {
+      return option;
+    }
+
+    var definition = config[key];
+    // Ignore options that are not defined
+    if (!definition) {
+      return;
+    }
+
+    if (stack.indexOf(key) >= 0) {
+      throw new Error('Recursive resolution denied.');
+    }
+
+    option = options[key];
+    var fallback = definition.default;
+    var appliedArgs = slice.call(arguments, 1);
+    var args = [definition.type, option].concat(appliedArgs);
+
+    function toResolve() {
+      stack.push(key);
+      var option = normalize.apply(resolver, args);
+
+      if (option == null) {
+        option = fallback;
+        if (typeof option === 'function') {
+          option = option.apply(resolver, appliedArgs);
+        }
+      }
+
+      return option;
+    }
+
+    function onResolve() {
+      stack.pop();
+    }
+
+    return tryResolve(toResolve, onResolve);
+  }
+
+
+  return resolver;
+}
+
+
+function tryResolve(toResolve, onResolve) {
+  try {
+    return toResolve();
+  } finally {
+    onResolve();
+  }
+}
+
+
+module.exports = createResolver;