feat: add JSONPathExtractor tool (#5052)

* feat: add JSONPathExtractor tool with lodash-based path extraction - Implement JSONPathExtractor tool for extracting values from JSON using path notation - Use lodash.get for robust path extraction supporting edge cases (numeric string keys, array indexing) - Add configurable error handling with returnNullOnError parameter - Include comprehensive test suite with 34 tests covering all scenarios - Support JSON strings, objects, and arrays as input * fix lint * Update pnpm-lock.yaml * fix: exclude test files from TypeScript compilation Prevents test files from being included in the dist folder which was causing "jest is not defined" errors during server startup. --------- Co-authored-by: Henry Heng <henryheng@flowiseai.com>
2026-06-22 15:01:13 +03:00 · 2025-08-18 02:55:58 -07:00
parent 4ce0851858
commit b126472816
7 changed files with 39438 additions and 38833 deletions
@@ -0,0 +1,125 @@
+import { z } from 'zod'
+import { StructuredTool } from '@langchain/core/tools'
+import { INode, INodeData, INodeParams } from '../../../src/Interface'
+import { getBaseClasses } from '../../../src/utils'
+import { get } from 'lodash'
+
+/**
+ * Tool that extracts values from JSON using path
+ */
+class JSONPathExtractorTool extends StructuredTool {
+    name = 'json_path_extractor'
+    description = 'Extract value from JSON using configured path'
+
+    schema = z.object({
+        json: z
+            .union([z.string().describe('JSON string'), z.record(z.any()).describe('JSON object'), z.array(z.any()).describe('JSON array')])
+            .describe('JSON data to extract value from')
+    })
+
+    private readonly path: string
+    private readonly returnNullOnError: boolean
+
+    constructor(path: string, returnNullOnError: boolean = false) {
+        super()
+        this.path = path
+        this.returnNullOnError = returnNullOnError
+    }
+
+    async _call({ json }: z.infer<typeof this.schema>): Promise<string> {
+        // Validate that path is configured
+        if (!this.path) {
+            if (this.returnNullOnError) {
+                return 'null'
+            }
+            throw new Error('No extraction path configured')
+        }
+
+        let data: any
+
+        // Parse JSON string if needed
+        if (typeof json === 'string') {
+            try {
+                data = JSON.parse(json)
+            } catch (error) {
+                if (this.returnNullOnError) {
+                    return 'null'
+                }
+                throw new Error(`Invalid JSON string: ${error instanceof Error ? error.message : 'Parse error'}`)
+            }
+        } else {
+            data = json
+        }
+
+        // Extract value using lodash get
+        const value = get(data, this.path)
+
+        if (value === undefined) {
+            if (this.returnNullOnError) {
+                return 'null'
+            }
+            const jsonPreview = JSON.stringify(data, null, 2)
+            const preview = jsonPreview.length > 200 ? jsonPreview.substring(0, 200) + '...' : jsonPreview
+            throw new Error(`Path "${this.path}" not found in JSON. Received: ${preview}`)
+        }
+
+        return typeof value === 'string' ? value : JSON.stringify(value)
+    }
+}
+
+/**
+ * Node implementation for JSON Path Extractor tool
+ */
+class JSONPathExtractor_Tools implements INode {
+    label: string
+    name: string
+    version: number
+    type: string
+    icon: string
+    category: string
+    description: string
+    baseClasses: string[]
+    inputs: INodeParams[]
+
+    constructor() {
+        this.label = 'JSON Path Extractor'
+        this.name = 'jsonPathExtractor'
+        this.version = 1.0
+        this.type = 'JSONPathExtractor'
+        this.icon = 'jsonpathextractor.svg'
+        this.category = 'Tools'
+        this.description = 'Extract values from JSON using path expressions'
+        this.baseClasses = [this.type, ...getBaseClasses(JSONPathExtractorTool)]
+        this.inputs = [
+            {
+                label: 'JSON Path',
+                name: 'path',
+                type: 'string',
+                description: 'Path to extract. Examples: data, user.name, items[0].id',
+                placeholder: 'data'
+            },
+            {
+                label: 'Return Null on Error',
+                name: 'returnNullOnError',
+                type: 'boolean',
+                default: false,
+                description: 'Return null instead of throwing error when extraction fails',
+                optional: true,
+                additionalParams: true
+            }
+        ]
+    }
+
+    async init(nodeData: INodeData, _: string): Promise<any> {
+        const path = (nodeData.inputs?.path as string) || ''
+        const returnNullOnError = (nodeData.inputs?.returnNullOnError as boolean) || false
+
+        if (!path) {
+            throw new Error('JSON Path is required')
+        }
+
+        return new JSONPathExtractorTool(path, returnNullOnError)
+    }
+}
+
+module.exports = { nodeClass: JSONPathExtractor_Tools }