From 10f4223028a0ca8c2e0a6454868128df763917b3 Mon Sep 17 00:00:00 2001
From: Matthew Kilgore <tankerkiller125@gmail.com>
Date: Fri, 7 Aug 2020 19:43:01 -0400
Subject: [PATCH] Add error warning if children attr is ever used

---
 js/src/common/Component.ts | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/js/src/common/Component.ts b/js/src/common/Component.ts
index 47f28aef4..91a0524fa 100644
--- a/js/src/common/Component.ts
+++ b/js/src/common/Component.ts
@@ -24,9 +24,7 @@ export default abstract class Component<T extends ComponentAttrs = any> implemen
   abstract view(vnode: Mithril.Vnode<T, this>): Mithril.Children;
 
   oninit(vnode: Mithril.Vnode<T, this>) {
-    this.initAttrs(vnode.attrs);
-
-    this.attrs = vnode.attrs;
+    this.setAttrs(vnode.attrs);
   }
 
   oncreate(vnode: Mithril.VnodeDOM<T, this>) {
@@ -34,9 +32,7 @@ export default abstract class Component<T extends ComponentAttrs = any> implemen
   }
 
   onbeforeupdate(vnode: Mithril.VnodeDOM<T, this>) {
-    this.initAttrs(vnode.attrs);
-
-    this.attrs = vnode.attrs;
+    this.setAttrs(vnode.attrs);
   }
 
   /**
@@ -67,6 +63,18 @@ export default abstract class Component<T extends ComponentAttrs = any> implemen
     return m(this as any, componentProps, children);
   }
 
+  private setAttrs(attrs: T) {
+    this.initAttrs(attrs);
+
+    if (attrs && 'children' in attrs) {
+      throw new Error(
+        'The "children" attribute of attrs should never be used. Either pass children in as the vnode children or rename the attribute'
+      );
+    }
+
+    this.attrs = attrs;
+  }
+
   protected initAttrs(attrs: T): T {
     return attrs;
   }