feat(utils): add is json string func

packages/utils/lib/__test__/jsonUtils.test.ts

@@ -1,4 +1,4 @@
-import { parseJSONSafely, stringifyObjSafely } from '../jsonUtils'
+import { parseJSONSafely, stringifyObjSafely, isJSONString } from '../jsonUtils'
 import { describe, it, expect } from 'vitest'
 
 describe('parseJSONSafely', () => {
@@ -28,3 +28,29 @@ describe('stringifyObjSafely', () => {
     expect(output).toEqual(input)
   })
 })
+
+describe('isJSONString', () => {
+  it('should return true for valid JSON strings', () => {
+    const input = '{"a":1,"b":2,"c":3}'
+    const output = isJSONString(input)
+    expect(output).toEqual(true)
+  })
+
+  it('should return false for invalid JSON strings', () => {
+    const input = '{a:1,b:2,c:3}'
+    const output = isJSONString(input)
+    expect(output).toEqual(false)
+  })
+
+  it('should return false for non-string inputs', () => {
+    const input = 123
+    const output = isJSONString(input as any)
+    expect(output).toEqual(false)
+  })
+
+  it('should return false for null', () => {
+    const input = null
+    const output = isJSONString(input as any)
+    expect(output).toEqual(false)
+  })
+})

packages/utils/lib/jsonUtils.ts

@@ -28,3 +28,18 @@ export const stringifyObjSafely = (obj: Record<string, any>, tabSpaces?: number)
     return 'stringify error'
   }
 }
+
+/**
+ * Checks if a given string is a valid JSON string.
+ * @param str - The string to be checked.
+ * @returns A boolean indicating whether the string is a valid JSON string or not.
+ */
+export const isJSONString = (str: string): boolean => {
+  if (typeof str !== 'string') return false
+  try {
+    const obj = JSON.parse(str)
+    return typeof obj === 'object' && obj !== null
+  } catch (e) {
+    return false
+  }
+}