From 91cbc54a67376ddb30ac36d7f9b7751a73a11e98 Mon Sep 17 00:00:00 2001
From: Timothy Johnson <timothy@idioticdev.com>
Date: Sun, 17 May 2020 03:12:15 -0700
Subject: [PATCH] Warn of missing class property

---
 .../compile/render_dom/wrappers/InlineComponent/index.ts       | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
index c818bdcf78..f57f08aa2e 100644
--- a/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
+++ b/src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts
@@ -574,6 +574,9 @@ export default class InlineComponentWrapper extends Wrapper {
 				${props && b`let ${props} = ${attribute_object};`}`}
 				${statements}
 				const ${name} = new ${expression}(${component_opts});
+				${uses_classes && component.compile_options.dev && b`if (${name}.$$.props.class === undefined) {
+					@_console.warn("<${this.node.name}> does not export class property but was used with a class directive.")
+				}`}
 
 				${munged_bindings}
 				${munged_handlers}