Allow args.conditions to be a single item, converted to array

wrap.js

@@ -14,8 +14,8 @@
  * @property {function(): Promise<SvelteComponent>} [asyncRoute] - Function that returns a Promise that fulfills with a Svelte component (e.g. `{asyncRoute: () => import('Foo.svelte')}`)
  * @property {SvelteComponent} [loadingRoute] - Svelte component to be displayed while the async route is loading; when unset or false-y, no route is shown while loading
  * @property {Object} [loadingParams] - Optional dictionary passed to the `loadingRoute` component as params (for an exported prop called `params`)
- * @property {Object} [userData] - Optional object that will be passed to each `conditionsFailed` event (can be omitted)
- * @property {RoutePrecondition[]} [conditions] - Route pre-conditions to add, which will be executed in order
+ * @property {Object} [userData] - Optional object that will be passed to events such as `routeLoading`, `routeLoaded`, `conditionsFailed`
+ * @property {RoutePrecondition[]|RoutePrecondition} [conditions] - Route pre-conditions to add, which will be executed in order
  */
 
 /**
@@ -47,7 +47,11 @@ export function wrap(args) {
     if (typeof args.asyncRoute != 'function') {
         throw Error('Parameter asyncRoute must be a function')
     }
-    if (args.conditions && args.conditions.length) {
+    if (args.conditions) {
+        // Ensure it's an array
+        if (!Array.isArray(args.conditions)) {
+            args.conditions = [args.conditions]
+        }
         for (let i = 0; i < args.conditions.length; i++) {
             if (!args.conditions[i] || typeof args.conditions[i] != 'function') {
                 throw Error('Invalid parameter conditions[' + i + ']')