progress

Thanks @Ludeeus
No errors on bundling now, but still issues when trying to load it on the front-end

.gitignore

@@ -1,5 +1,5 @@
 /node_modules/
 /.rts2_cache_umd/
 yarn.lock
-/dist/BOILERPLATE-card.js.map
+/dist/boilerplate-card.js.map
 /dist/index.d.ts

index.ts

@@ -8,16 +8,16 @@ import {
   css
 } from "lit-element";
 
-interface BOILERPLATEConfig {
+interface BoilerplateConfig {
   type: string;
 }
 
-@customElement("BOILERPLATE-card")
-class BOILERPLATECard extends LitElement {
+@customElement("boilerplate-card")
+class BoilerplateCard extends LitElement {
   @property() public hass?: any;
-  @property() private _config?: BOILERPLATEConfig;
+  @property() private _config?: BoilerplateConfig;
 
-  public setConfig(config: BOILERPLATEConfig): void {
+  public setConfig(config: BoilerplateConfig): void {
     if (!this._config) {
       // TODO Log error
     }
@@ -31,7 +31,7 @@ class BOILERPLATECard extends LitElement {
     }
 
     return html`
-      <div>BOILERPLATE</div>
+      <div>boilerplate</div>
     `;
   }
 
@@ -42,6 +42,6 @@ class BOILERPLATECard extends LitElement {
 
 declare global {
   interface HTMLElementTagNameMap {
-    "BOILERPLATE-card": BOILERPLATECard;
+    "boilerplate-card": BoilerplateCard;
   }
 }

package.json

@@ -1,5 +1,5 @@
 {
-    "name": "BOILERPLATE-card",
+    "name": "boilerplate-card",
     "version": "1.0.0",
     "description": "A templatable config pass-through",
     "keywords": [
@@ -10,8 +10,8 @@
         "lovelace",
         "custom-cards"
     ],
-    "umd:main": "BOILERPLATE-card.js",
-    "repository": "git@github.com:custom_cards/BOILERPLATE-card.git",
+    "umd:main": "boilerplate-card.js",
+    "repository": "git@github.com:custom_cards/boilerplate-card.git",
     "author": "Ian Richardson <iantrich@gmail.com>",
     "license": "MIT",
     "dependencies": {
@@ -29,7 +29,7 @@
     },
     "scripts": {
         "start": "microbundle watch",
-        "build": "npm run lint && microbundle --globals lit-element --target browser --format umd",
+        "build": "npm run lint && microbundle --external litElement --target browser --format umd",
         "lint": "tslint index.ts"
     }
 }