Prevent displaying post editor welcome guide

This is rather an edge case when users open the email editor
before they have opened the post editor.
It also happens in acceptance tests.
[MAILPOET-5365]

mailpoet/assets/js/src/email_editor/core/hooks/index.ts

@@ -0,0 +1,21 @@
+import { useEffect } from '@wordpress/element';
+import { useSelect, dispatch } from '@wordpress/data';
+import { store as editPostStore } from '@wordpress/edit-post';
+
+// This custom hook disables the post editor welcome guide
+export function useDisableWelcomeGuide() {
+  const { isWelcomeGuideActive } = useSelect((select) => ({
+    isWelcomeGuideActive: select(editPostStore).isFeatureActive(
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
+      // The isFeatureActive accepts an attribute but typescript thinks it doesn't
+      'welcomeGuide',
+    ),
+  }));
+
+  useEffect(() => {
+    if (isWelcomeGuideActive) {
+      dispatch(editPostStore).toggleFeature('welcomeGuide');
+    }
+  }, [isWelcomeGuideActive]);
+}

mailpoet/assets/js/src/email_editor/email_editor.tsx

@@ -3,6 +3,7 @@ import { useSelect, select as directSelect } from '@wordpress/data';
 import { store as coreStore } from '@wordpress/core-data';
 import { store as editorStore } from '@wordpress/editor';
 import { NextButtonSlot } from './core/components/next_button_slot';
+import { useDisableWelcomeGuide } from './core/hooks';
 import { NextButton } from './integration/components/next_button';
 import { MailPoetEmailData } from './types';
 
@@ -23,6 +24,9 @@ function Editor() {
       ) as MailPoetEmailData) ?? null,
   }));
 
+  // We don't want to show the editor welcome guide as it is not relevant to emails
+  useDisableWelcomeGuide();
+
   return (
     <NextButtonSlot>
       <NextButton newsletterId={mailpoetData?.id ?? null} />

mailpoet/assets/js/src/types/wordpress_modules.ts

@@ -30,6 +30,21 @@ declare module '@wordpress/editor' {
   }>;
 }
 
+// We need to use code/edit-post store but types are not available yet
+declare module '@wordpress/edit-post' {
+  import * as editPostActions from '@wordpress/edit-post/store/actions';
+  import * as editPostSelectors from '@wordpress/edit-post/store/selectors';
+  import { StoreDescriptor as GenericStoreDescriptor } from '@wordpress/data/build-types/types';
+
+  export * from '@wordpress/edit-post/index';
+
+  export const store: { name: 'core/edit-post' } & GenericStoreDescriptor<{
+    reducer: () => unknown;
+    actions: typeof editPostActions;
+    selectors: typeof editPostSelectors;
+  }>;
+}
+
 // there are no @types/wordpress__interface yet
 declare module '@wordpress/interface' {
   import { StoreDescriptor } from '@wordpress/data/build-types/types';