fix: copying on circular JSON/Array throws error

src/hooks/useCopyToClipboard.ts

@@ -3,6 +3,7 @@ import { useCallback, useRef, useState } from 'react'
 
 import { useJsonViewerStore } from '../stores/JsonViewerStore'
 import type { JsonViewerOnCopy } from '../type'
+import { circularStringify } from '../utils'
 
 /**
  * useClipboard hook accepts one argument options in which copied status timeout duration is defined (defaults to 2000). Hook returns object with properties:
@@ -51,9 +52,8 @@ export function useClipboard ({ timeout = 2000 } = {}) {
           }]`, error)
       }
     } else {
-      const valueToCopy = JSON.stringify(
+      const valueToCopy = circularStringify(
         typeof value === 'function' ? value.toString() : value,
-        null,
         '  '
       )
       if ('clipboard' in navigator) {

src/utils/index.ts

@@ -150,3 +150,23 @@ export function segmentArray<T> (arr: T[], size: number): T[][] {
   }
   return result
 }
+
+// https://stackoverflow.com/a/72457899
+export function circularStringify (obj: any, space?: string | number) {
+  const seenValues = []
+
+  function circularReplacer (key: string | number, value: any) {
+    if (typeof value === 'object' && value !== null && Object.keys(value).length) {
+      const stackSize = seenValues.length
+      if (stackSize) {
+        // clean up expired references
+        for (let n = stackSize - 1; seenValues[n][key] !== value; --n) { seenValues.pop() }
+        if (seenValues.includes(value)) return '[Circular]'
+      }
+      seenValues.push(value)
+    }
+    return value
+  }
+
+  return JSON.stringify(obj, circularReplacer, space)
+}

tests/util.test.tsx

@@ -4,7 +4,7 @@ import { describe, expect, test } from 'vitest'
 
 import type { DataItemProps, Path } from '../src'
 import { applyValue, createDataType, isCycleReference } from '../src'
-import { segmentArray } from '../src/utils'
+import { circularStringify, segmentArray } from '../src/utils'
 
 describe('function applyValue', () => {
   const patches: any[] = [{}, undefined, 1, '2', 3n, 0.4]
@@ -235,3 +235,49 @@ describe('function segmentArray', () => {
     ])
   })
 })
+
+describe('function circularStringify', () => {
+  test('should works as JSON.stringify', () => {
+    const obj = { foo: 1, bar: 2 }
+    expect(circularStringify(obj)).to.eq(JSON.stringify(obj))
+  })
+
+  test('should works with circular reference in object', () => {
+    const obj = {
+      foo: 1,
+      bar: {
+        foo: 2,
+        bar: null
+      }
+    }
+    obj.bar.bar = obj.bar
+    expect(circularStringify(obj)).to.eq('{"foo":1,"bar":{"foo":2,"bar":"[Circular]"}}')
+  })
+
+  test('should works with circular reference in array', () => {
+    const array = [1, 2, 3, 4, 5]
+    // @ts-expect-error ignore
+    array[2] = array
+    expect(circularStringify(array)).to.eq('[1,2,"[Circular]",4,5]')
+  })
+
+  test('should works with complex circular object', () => {
+    const obj = {
+      a: {
+        b: {
+          c: 1,
+          d: 2
+        }
+      },
+      e: {
+        f: 3,
+        g: 4
+      }
+    }
+    // @ts-expect-error ignore
+    obj.a.b.e = obj.e
+    // @ts-expect-error ignore
+    obj.e.g = obj.a.b
+    expect(circularStringify(obj)).to.eq('{"a":{"b":{"c":1,"d":2,"e":{"f":3,"g":"[Circular]"}}},"e":{"f":3,"g":"[Circular]"}}')
+  })
+})