Detect circular references in var_dump (#470)

* Detect circular references in var_dump

* Update CHANGELOG.md

CHANGELOG.md

@@ -38,6 +38,7 @@ Ideas that will be planned and find their way into a release at one point
 Released: TBA. [Diff](https://github.com/locutusjs/locutus/compare/v2.0.30...main).
 
 - [ ]
+- [x] Make var_dump detect circular references (fixes #305)
 
 ## v2.0.30
 

src/php/var/var_dump.js

@@ -1,12 +1,17 @@
+const visitedObjects = new Map() // Initialize a map to track visited objects
+
 module.exports = function var_dump() {
   //  discuss at: https://locutus.io/php/var_dump/
   // original by: Brett Zamir (https://brett-zamir.me)
   // improved by: Zahlii
   // improved by: Brett Zamir (https://brett-zamir.me)
   //      note 1: For returning a string, use var_export() with the second argument set to true
-  //        test: skip-all
   //   example 1: var_dump(1)
   //   returns 1: 'int(1)'
+  //   example 2: const simpleCircular = {}
+  //   example 2: simpleCircular.self = simpleCircular
+  //   example 2: var_dump(simpleCircular)
+  //   returns 2: 'array(1) {\n    [self] =>\n    Circular Reference Detected\n}\n'
 
   const echo = require('../strings/echo')
   let output = ''
@@ -107,7 +112,7 @@ module.exports = function var_dump() {
     return ret
   }
 
-  const _formatArray = function (obj, curDepth, padVal, padChar) {
+  const _formatArray = function (obj, curDepth, padVal, padChar, visitedObjects) {
     if (curDepth > 0) {
       curDepth++
     }
@@ -118,6 +123,14 @@ module.exports = function var_dump() {
     let val = ''
 
     if (typeof obj === 'object' && obj !== null) {
+      if (visitedObjects.has(obj)) {
+        // Circular reference detected, return a placeholder or a message
+        return 'Circular Reference Detected\n'
+      } else {
+        // Mark this object as visited by adding it to the map
+        visitedObjects.set(obj, true)
+      }
+
       if (obj.constructor && _getFuncName(obj.constructor) === 'LOCUTUS_Resource') {
         return obj.var_dump()
       }
@@ -142,7 +155,7 @@ module.exports = function var_dump() {
           str += key
           str += '] =>\n'
           str += thickPad
-          str += _formatArray(objVal, curDepth + 1, padVal, padChar)
+          str += _formatArray(objVal, curDepth + 1, padVal, padChar, visitedObjects)
         } else {
           val = _getInnerVal(objVal, thickPad)
           str += thickPad
@@ -161,9 +174,9 @@ module.exports = function var_dump() {
     return str
   }
 
-  output = _formatArray(arguments[0], 0, padVal, padChar)
+  output = _formatArray(arguments[0], 0, padVal, padChar, visitedObjects)
   for (i = 1; i < arguments.length; i++) {
-    output += '\n' + _formatArray(arguments[i], 0, padVal, padChar)
+    output += '\n' + _formatArray(arguments[i], 0, padVal, padChar, visitedObjects)
   }
 
   echo(output)

test/languages/php/var/test-var_dump.js

@@ -6,11 +6,19 @@ var ini_set = require('../../../../src/php/info/ini_set') // eslint-disable-line
 var ini_get = require('../../../../src/php/info/ini_get') // eslint-disable-line no-unused-vars,camelcase
 var var_dump = require('../../../../src/php/var/var_dump.js') // eslint-disable-line no-unused-vars,camelcase
 
-describe.skip('src/php/var/var_dump.js (tested in test/languages/php/var/test-var_dump.js)', function () {
+describe('src/php/var/var_dump.js (tested in test/languages/php/var/test-var_dump.js)', function () {
   it('should pass example 1', function (done) {
     var expected = 'int(1)'
     var result = var_dump(1)
     expect(result).to.deep.equal(expected)
     done()
   })
+  it('should pass example 2', function (done) {
+    var expected = 'array(1) {\n    [self] =>\n    Circular Reference Detected\n}\n'
+    const simpleCircular = {}
+    simpleCircular.self = simpleCircular
+    var result = var_dump(simpleCircular)
+    expect(result).to.deep.equal(expected)
+    done()
+  })
 })