[lexical] Chore: Added missing isInline function to TextNode (#7226)

Co-authored-by: Bob Ippolito <[email protected]>

Author: mrdivyansh

packages/lexical/flow/Lexical.js.flow

@@ -623,6 +623,7 @@ declare export class TextNode extends LexicalNode {
   getFormat(): number;
   getStyle(): string;
   isComposing(): boolean;
+  isInline(): true;
   isToken(): boolean;
   isSegmented(): boolean;
   isDirectionless(): boolean;
@@ -698,6 +699,7 @@ declare export class LineBreakNode extends LexicalNode {
   getTextContent(): '\n';
   createDOM(): HTMLElement;
   updateDOM(): false;
+  isInline(): true;
   static importJSON(
     serializedLineBreakNode: SerializedLineBreakNode,
   ): LineBreakNode;

packages/lexical/src/nodes/LexicalLineBreakNode.ts

@@ -50,6 +50,10 @@ export class LineBreakNode extends LexicalNode {
     return false;
   }
 
+  isInline(): true {
+    return true;
+  }
+
   static importDOM(): DOMConversionMap | null {
     return {
       br: (node: Node) => {

packages/lexical/src/nodes/LexicalTextNode.ts

@@ -473,6 +473,13 @@ export class TextNode extends LexicalNode {
     return true;
   }
 
+  /**
+   * @returns true if the text node is inline, false otherwise.
+   */
+  isInline(): true {
+    return true;
+  }
+
   // View
 
   createDOM(config: EditorConfig, editor?: LexicalEditor): HTMLElement {