Disregard block components from ejection which are unmounted during parent blocks lifecycles

packages/client/src/components/Block.svelte

@@ -9,7 +9,7 @@
   let structureLookupMap = {}
 
   const registerBlockComponent = (id, order, parentId, instance) => {
-    // Ensure child array exists
+    // Ensure child map exists
     if (!structureLookupMap[parentId]) {
       structureLookupMap[parentId] = {}
     }
@@ -18,6 +18,14 @@
     structureLookupMap[parentId][order] = instance
   }
 
+  const unregisterBlockComponent = (order, parentId) => {
+    // Ensure child map exists
+    if (!structureLookupMap[parentId]) {
+      return
+    }
+    delete structureLookupMap[parentId][order]
+  }
+
   const eject = () => {
     // Start the new structure with the root component
     let definition = structureLookupMap[$component.id][0]
@@ -73,6 +81,7 @@
     // We register block components with their raw props so that we can eject
     // blocks later on
     registerComponent: registerBlockComponent,
+    unregisterComponent: unregisterBlockComponent,
   })
 
   onMount(() => {

packages/client/src/components/BlockComponent.svelte

@@ -1,5 +1,5 @@
 <script>
-  import { getContext } from "svelte"
+  import { getContext, onDestroy } from "svelte"
   import { generate } from "shortid"
   import { builderStore } from "../stores/builder.js"
   import Component from "components/Component.svelte"
@@ -41,6 +41,12 @@
       block.registerComponent(id, order ?? 0, $component?.id, instance)
     }
   }
+
+  onDestroy(() => {
+    if ($builderStore.inBuilder) {
+      block.unregisterComponent(order ?? 0, $component?.id)
+    }
+  })
 </script>
 
 <Component {instance} isBlock>