resettable

resettable-object

Reset object to its original state using JSON Patch with less strict rules. Maybe used to undo auto generated configuration data.

• Description
• Synopsis
  • Modify package.json file
  • Reset package.json to its original state
• API
  • Functions
  • Typedefs
  • reset([data], [history], [options]) ⇒ Array.<Operation> | undefined
  • diff([currentObject], [originalObject]) ⇒ Array.<Operation>
  • mayChange(currentObject, originalObject, path) ⇒ boolean
  • Path : string | number | Array.<(number|string)>
  • Operation : Object

Description

Provide functions to get diff of two objects and use that diff to reset object into its original state. Uses less strict rules than JSON Patch. Maybe used to undo auto generated configuration data.

Synopsis

Modify package.json file

import { mayChange, diff, reset, clone } from "resettable";
import fs from "fs";
import isEqual from "lodash.isEqual";
 
const originalPkg = JSON.parse(fs.readFileSync(`${__dirname}/../package.json`, "utf8")); // Read package.json
const pkg: any = clone(originalPkg); // Clone it for changes.
pkg.scripts.myScript = "echo 1"; // Add some script.
 
// Look if scripts.test can be changed safely. (Not same with "test in scripts", See API.)
if (mayChange(pkg, originalPkg, "scripts.test")) {
  pkg.scripts.test = "test-different";
}
 
const patch = diff(pkg, originalPkg);
 
fs.writeFileSync(`${__dirname}/../package.json`, JSON.stringify(pkg, undefined, 2)); // Write package.json
fs.writeFileSync(`${__dirname}/../patch.json`, JSON.stringify(patch, undefined, 2)); // Write patch.json

Reset package.json to its original state

const pkgFromDisk = JSON.parse(fs.readFileSync(`${__dirname}/../package.json`, "utf8")); // Read package.json
const patchFromDisk = JSON.parse(fs.readFileSync(`${__dirname}/../patch.json`, "utf8")); // Read package.json
reset(pkgFromDisk, patchFromDisk);
 
fs.writeFileSync(`${__dirname}/../package.json`, JSON.stringify(pkgFromDisk, undefined, 2)); // Write package.json
fs.writeFileSync(`${__dirname}/../patch.json`, JSON.stringify({}, undefined, 2)); // Clear patch.json

API

Functions

reset([data], [history], [options]) ⇒ Array.<Operation> | undefined

Resets given object to its original satate using given array of operations. Different from JSON Patch standard, uses more relaxed rules. For example rejected operations does stop further execution, values to be replaced in arrays are searched in different index positions etc. Please note: This function mutates data object.

diff([currentObject], [originalObject]) ⇒ Array.<Operation>

Compares two objects and returns operations needed to reset current object into original object.

mayChange(currentObject, originalObject, path) ⇒ boolean

Checks whether value at given path is safe to change by comparing cuurent object to original object. May be used to test whether values in given path are created/modified by user and safe to change. Like "in" operator, returns true if there is no entry for given path. However, differently, it returns true if value exist in modified object but it is different from original, assuming it is modified using this library and may be changed further.

Typedefs

Path : string | number | Array.<(number|string)>

Type for storing path of object or array element as a chained string or array.

Operation : Object

Type for storing operations.

reset([data], [history], [options]) ⇒ Array.<Operation> | undefined

Resets given object to its original satate using given array of operations. Different from JSON Patch standard, uses more relaxed rules. For example rejected operations does stop further execution, values to be replaced in arrays are searched in different index positions etc. Please note: This function mutates data object.

Kind: global function
Returns: Array.<Operation> | undefined -

Returns array of operations which are skipped, undefined if all operations are applied.

Param	Type	Default	Description
[data]	Object		Data to be reset.
[history]	Array.<Operation>	[]	Array of operations to execute.
[options]	OperationOptions		Options
[options.force]	boolean	false	Forces operation even it is not safe.
[options.exact]	boolean	false	Modifies find algorithm for arrays. If true, function searches given value in given exact position. Otherwise searches all array.
[options.checkDuplicate]	boolean	true	Checks duplicate values in array. If true, when duplicate value is present, add/replace operation is skipped.
[options.addNotFound]	boolean	true	If true, during replace, adds given value even replaced key is not present in array or object.
[options.clean]	boolean	true	If true, removes empty objects, empty arrays, empty strings, null and undefined values from objects and arrays.

diff([currentObject], [originalObject]) ⇒ Array.<Operation>

Compares two objects and returns operations needed to reset current object into original object.

Kind: global function
Returns: Array.<Operation> -

Array of operations to apply to current object to get original object.

Param	Type	Default	Description
[currentObject]	object	{}	Object to be used in reset function.
[originalObject]	object	{}	Original object to get after reset operation.

mayChange(currentObject, originalObject, path) ⇒ boolean

Checks whether value at given path is safe to change by comparing cuurent object to original object. May be used to test whether values in given path are created/modified by user and safe to change. Like "in" operator, returns true if there is no entry for given path. However, differently, it returns true if value exist in modified object but it is different from original, assuming it is modified using this library and may be changed further.

Kind: global function
Returns: boolean -

Whether given path has same value as original path.

Param	Type	Description
currentObject	object	Current object.
originalObject	object	Original object.
path	Array.<(string|number)> | string | number	Path to get result for.

Path : string | number | Array.<(number|string)>

Type for storing path of object or array element as a chained string or array.

Kind: global typedef
Example

const path = "member.name"; // { member: { name: ... } }
const other = ["member", "first.name"]; // { member: { "first.name": ... } }

Operation : Object

Type for storing operations.

Kind: global typedef
Properties

Name	Type	Description
op	string	Operation to execte: test, remove, add , replace. (test checks the existence of value at given path).
path	string	Path to make changes at.
value	*	Value to be used in operation.