feat(vdom): check context child node type in dev mode

localvoid · May 14, 2018 · 8c8f97f · 8c8f97f
1 parent 499b707
commit 8c8f97f
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diff --git a/packages/ivi/__tests__/vnode_context.spec.ts b/packages/ivi/__tests__/vnode_context.spec.ts
@@ -0,0 +1,10 @@
+import { context, fragment } from "ivi";
+import * as h from "ivi-html";
+
+test(`assigning children collection should raise an exception`, () => {
+  expect(() => (
+    context({},
+      fragment(h.div(), h.div())!,
+    )
+  )).toThrowError("singular");
+});
diff --git a/packages/ivi/src/vdom/vnode_factories.ts b/packages/ivi/src/vdom/vnode_factories.ts
@@ -226,6 +226,12 @@ export function statefulComponent<P>(
  * @returns context node.
  */
 export function context<T = {}>(ctx: T, child: VNode): VNode<T> {
+  /* istanbul ignore else */
+  if (DEBUG) {
+    if (child.prev !== child) {
+      throw new Error("Context node contains an invalid child. Child should be a singular VNode.");
+    }
+  }
   return new VNode<T>(
     VNodeFlags.UpdateContext,
     null,