added support for replace

Author: vivekburman

jsondiff.js

@@ -6,7 +6,8 @@ export default class JSONDiff {
  constructor(oldObj, newObj) {
  this.oldObj = oldObj;
  this.newObj = newObj;
- this.jsonPatch = []; 
+ this.jsonPatch = [];
+ this.deletes = {}; 
  }
 
  isEmpty = (obj) => {
@@ -33,12 +34,16 @@ export default class JSONDiff {
  generateArrDiff(oldArr, newArr, path) {
  this.walkMiddleSnake(oldArr, newArr, path);
  }
-
- generateObjDiff(oldObj=this.oldObj, newObj=this.newObj, path='') {
+ setDelete(path) {
+ // make sure inserted to jsonPatch first else will be error
+ this.deletes[path] = this.jsonPatch.length - 1;
+ }
+ generateObjDiff(oldObj=this.oldObj, newObj=this.newObj, path='', pushToArr=this.jsonPatch) {
  if (this.isEmpty(oldObj)) {
- this.jsonPatch.push({op: "add", path: "/", value: newObj});
+ pushToArr.push({op: "add", path: "/", value: newObj});
  } else if (this.isEmpty(newObj)) {
- this.jsonPatch.push({op: "delete", path: "/"});
+ pushToArr.push({op: "delete", path: "/"});
+ this.setDelete('/');
  } else {
  const oldKeys = this.getKeys(oldObj);
  const newKeys = this.getKeys(newObj);
@@ -51,10 +56,12 @@ export default class JSONDiff {
  // 1.4. else same, then skip
 
  if (!newObj.hasOwnProperty(oldKeys[t])) {
- this.jsonPatch.push({op: "delete", path: `${path}/${oldKeys[t]}`});
+ const _p = `${path}/${oldKeys[t]}`;
+ pushToArr.push({op: "delete", path: _p});
+ this.setDelete(_p);
  }
  else if (newObj[oldKeys[t]] != oldObj[oldKeys[t]]) {
- this.jsonPatch.push({op: "replace", path: `${path}/${oldKeys[t]}`, value: newObj[oldKeys[t]]});
+ pushToArr.push({op: "replace", path: `${path}/${oldKeys[t]}`, value: newObj[oldKeys[t]]});
  }
  }
 
@@ -64,7 +71,10 @@ export default class JSONDiff {
  // 2.3 else recursive call
 
  if (!newObj.hasOwnProperty(oldKeys[t])) {
- this.jsonPatch.push({op: "delete", path: `${path}/${oldKeys[t]}`});
+ const _p = `${path}/${oldKeys[t]}`;
+ pushToArr.push({op: "delete", path: _p});
+ this.setDelete(_p);
+
  } else {
  this.generateObjDiff(oldObj[oldKeys[t]], newObj[oldKeys[t]], `${path}/${oldKeys[t]}`);
  }
@@ -78,7 +88,7 @@ export default class JSONDiff {
  // 4. add all the remaining new properties to patch
  for (let t = 0; t < newKeys.length; t++) {
  if (!this.isEmpty(newObj[newKeys[t]]) && !oldObj.hasOwnProperty(newKeys[t])) {
- this.jsonPatch.push({op: "add", path: `${path}/${newKeys[t]}`, value: newObj[newKeys[t]]});
+ pushToArr.push({op: "add", path: `${path}/${newKeys[t]}`, value: newObj[newKeys[t]]});
  }
  }
  }
@@ -206,19 +216,16 @@ export default class JSONDiff {
  ];
  }
  callbackFunc (x1, y1, x2, y2, oldArr, newArr, path_) {
- const lastIndex = Math.max(0, this.jsonPatch.length - 1);
  if (x1 == x2) {
- if (typeof newArr[y1] == 'object' && !Array.isArray(newArr[y1]) && 
- (this.jsonPatch[lastIndex]?.path == `${path_}/${y1}` 
- && this.jsonPatch[lastIndex]?.op == 'delete')) {
+ const _p = `${path_}/${y1}`;
+ if (typeof newArr[y1] == 'object' && !Array.isArray(newArr[y1]) && this.deletes.hasOwnProperty(_p)) {
  // if there is a delete at same index and the type is object check for partial update
- this.jsonPatch.pop();
- this.generateObjDiff(oldArr[y1], newArr[y1], `${path_}/${y1}`);
+ const arr = [];
+ this.generateObjDiff(oldArr[y1], newArr[y1], `${path_}/${y1}`, arr);
+ this.jsonPatch.splice(this.deletes[_p], 1, ...arr);
  } else {
- if ((this.jsonPatch[lastIndex]?.path == `${path_}/${y1}` 
- && this.jsonPatch[lastIndex]?.op == 'delete')) {
- this.jsonPatch.pop();
- this.jsonPatch.push({
+ if (this.deletes.hasOwnProperty(_p)) {
+ this.jsonPatch.splice(this.deletes[_p], 1, {
  op: 'replace',
  path: `${path_}/${y1}`,
  value: newArr[y1]
@@ -232,10 +239,12 @@ export default class JSONDiff {
  }
  }
  } else if(y1 == y2) {
+ const _p = `${path_}/${x1}`;
  this.jsonPatch.push({
  op: 'delete',
- path: `${path_}/${x1}`
+ path: _p
  });
+ this.setDelete(_p);
  }
  }
  walkMiddleSnake(oldArr, newArr, path_) {