chore($resource): refactor confusing case statement

Author: jessehouchins

src/ngResource/resource.js

@@ -503,45 +503,33 @@ angular.module('ngResource', ['ng']).
         forEach(actions, function (action, name) {
           var hasBody = /^(POST|PUT|PATCH)$/i.test(action.method);
 
-          Resource[name] = function (a1, a2, a3, a4) {
-            var params = {}, data, success, error;
-
-            /* jshint -W086 */ /* (purposefully fall through case statements) */
-            switch (arguments.length) {
-              case 4:
-                error = a4;
-                success = a3;
-              //fallthrough
-              case 3:
-              case 2:
-                if (isFunction(a2)) {
-                  if (isFunction(a1)) {
-                    success = a1;
-                    error = a2;
-                    break;
-                  }
-
-                  success = a2;
-                  error = a3;
-                  //fallthrough
-                } else {
-                  params = a1;
-                  data = a2;
-                  success = a3;
-                  break;
-                }
-              case 1:
-                if (isFunction(a1)) success = a1;
-                else if (hasBody) data = a1;
-                else params = a1;
-                break;
-              case 0: break;
-              default:
-                throw $resourceMinErr('badargs',
-                  "Expected up to 4 arguments [params, data, success, error], got {0} arguments",
-                  arguments.length);
+          Resource[name] = function () {
+            if (arguments.length > 4) {
+              throw $resourceMinErr('badargs',
+                "Expected up to 4 arguments " +
+                "[params, data, success, error], " +
+                "got {0} arguments",
+                arguments.length);
+            }
+
+            var params, data, success, error;
+
+            // Find success and error callbacks
+            for (var i = 0; i < arguments.length; i++) {
+              if (isFunction(arguments[i])) {
+                if (success) error = arguments[i];
+                else success = arguments[i];
+                arguments[i] = undefined; // reset to avoid setting data or params to a function
+              }
+            }
+
+            // Set data and params
+            if (arguments.length <= 2 && hasBody) {
+              data = arguments[0];
+            } else {
+              params = arguments[0];
+              data = arguments[1];
             }
-            /* jshint +W086 */ /* (purposefully fall through case statements) */
 
             var isInstanceCall = this instanceof Resource;
             var value = isInstanceCall ? data : (action.isArray ? [] : new Resource(data));