Corrected import statement and added checks in getNodesFromDocument function

packages/core/src/Node.ts

@@ -226,9 +226,34 @@ export class IndexNode extends TextNode {
  * A document is just a special text node with a docId.
  */
 export class Document extends TextNode {
-  constructor(init?: Partial<Document>) {
+  constructor(init?: Partial<Document>, type: string = 'text') {
+    if (!init) {
+      throw new Error("init parameter is null or undefined");
+    }
+    if (type !== 'text' && type !== 'json') {
+      throw new Error("type must be either 'text' or 'json'");
+    }
     super(init);
-    Object.assign(this, init);
+    if (type === 'json') {
+      this.text = this.jsonToText(init.text);
+    } else {
+      Object.assign(this, init);
+    }
+  }
+
+  private jsonToText(jsonData: any): string {
+    if (typeof jsonData !== 'object' || jsonData === null) {
+      throw new Error("jsonData must be an object");
+    }
+    let text = '';
+    for (let key in jsonData) {
+      if (typeof jsonData[key] === 'object' && jsonData[key] !== null) {
+        text += `${key}: ${this.jsonToText(jsonData[key])}\n`;
+      } else {
+        text += `${key}: ${jsonData[key]}\n`;
+      }
+    }
+    return text;
   }
 
   getType() {

packages/core/src/NodeParser.ts

@@ -34,6 +34,13 @@ export function getNodesFromDocument(
 ) {
   let nodes: TextNode[] = [];
 
+  if (document.type !== 'text' && document.type !== 'json') {
+    throw new Error("document.type must be either 'text' or 'json'");
+  }
+  if (document.type === 'json') {
+    document.text = document.jsonToText(JSON.parse(document.text));
+  }
+
   const textSplits = getTextSplitsFromDocument(document, textSplitter);
 
   textSplits.forEach((textSplit) => {