fix(components/weaviate): fix metadata special chars upsertion failure (#4436)

* Enhancement: Add recursive key normalization for metadata in Weaviate vector store

- Introduced `normalizeKeysRecursively` utility to standardize metadata keys.
- Updated Weaviate vector store to apply normalization on document metadata before processing.

* format(compnonents/utils): format for ci

* Update utils.ts

---------

Co-authored-by: Henry Heng <henryheng@flowiseai.com>

packages/components/nodes/vectorstores/Weaviate/Weaviate.ts

@@ -4,7 +4,7 @@ import { WeaviateLibArgs, WeaviateStore } from '@langchain/weaviate'
 import { Document } from '@langchain/core/documents'
 import { Embeddings } from '@langchain/core/embeddings'
 import { ICommonObject, INode, INodeData, INodeOutputsValue, INodeParams, IndexingResult } from '../../../src/Interface'
-import { getBaseClasses, getCredentialData, getCredentialParam } from '../../../src/utils'
+import { getBaseClasses, getCredentialData, getCredentialParam, normalizeKeysRecursively } from '../../../src/utils'
 import { addMMRInputParams, resolveVectorStoreOrRetriever } from '../VectorStoreUtils'
 import { index } from '../../../src/indexing'
 import { VectorStore } from '@langchain/core/vectorstores'
@@ -175,7 +175,11 @@ class Weaviate_VectorStores implements INode {
             const finalDocs = []
             for (let i = 0; i < flattenDocs.length; i += 1) {
                 if (flattenDocs[i] && flattenDocs[i].pageContent) {
-                    finalDocs.push(new Document(flattenDocs[i]))
+                    const doc = { ...flattenDocs[i] }
+                    if (doc.metadata) {
+                        doc.metadata = normalizeKeysRecursively(doc.metadata)
+                    }
+                    finalDocs.push(new Document(doc))
                 }
             }
 

packages/components/src/utils.ts

@@ -1216,6 +1216,35 @@ export const handleDocumentLoaderDocuments = async (loader: DocumentLoader, text
     return docs
 }
 
+/**
+ * Normalize special characters in key to be used in vector store
+ * @param str - Key to normalize
+ * @returns Normalized key
+ */
+export const normalizeSpecialChars = (str: string) => {
+    return str.replace(/[^a-zA-Z0-9_]/g, '_')
+}
+
+/**
+ * recursively normalize object keys
+ * @param data - Object to normalize
+ * @returns Normalized object
+ */
+export const normalizeKeysRecursively = (data: any): any => {
+    if (Array.isArray(data)) {
+        return data.map(normalizeKeysRecursively)
+    }
+
+    if (data !== null && typeof data === 'object') {
+        return Object.entries(data).reduce((acc, [key, value]) => {
+            const newKey = normalizeSpecialChars(key)
+            acc[newKey] = normalizeKeysRecursively(value)
+            return acc
+        }, {} as Record<string, any>)
+    }
+    return data
+}
+
 /**
  * Check if OAuth2 token is expired and refresh if needed
  * @param {string} credentialId