Allow link-previews to trigger without needing a space

Co-authored-by: Chris Svenningsen <chris@carbonfive.com>

ts/components/CompositionInput.tsx

@@ -377,14 +377,23 @@ export const CompositionInput: React.ComponentType<Props> = props => {
         return;
       }
 
-      if (propsRef.current.onEditorStateChange) {
+      const { onEditorStateChange } = propsRef.current;
+
+      if (onEditorStateChange) {
+        // `getSelection` inside the `onChange` event handler will be the
+        // selection value _before_ the change occurs. `setTimeout` 0 here will
+        // let `getSelection` return the selection after the change takes place.
+        // this is necessary for `maybeGrabLinkPreview` as it needs the correct
+        // `caretLocation` from the post-change selection index value.
+        setTimeout(() => {
           const selection = quill.getSelection();
 
-        propsRef.current.onEditorStateChange(
+          onEditorStateChange(
             text,
             mentions,
             selection ? selection.index : undefined
           );
+        }, 0);
       }
     }