feat: add datalayer errors

src/data-layer/data-layer-error.ts

@@ -0,0 +1,19 @@
+import { WarningError } from '../error'
+
+export function throwIsServer() {
+  throw new WarningError(
+    'window.dataLayer is not available on server-side. Make sure to only trigger events after your app is running on the client-side.'
+  )
+}
+
+export function throwIsNotDefined() {
+  throw new WarningError(
+    'window.dataLayer is not defined. Probably you forgot to add the Google Tag Manager script to your application.'
+  )
+}
+
+export function throwIsNotArray() {
+  throw new WarningError(
+    'window.dataLayer is not an array. Make sure you installed Google Tag Manager correctly.'
+  )
+}