ImmutableUpdater Documentation

The ImmutableUpdater class is a utility for performing immutable updates on nested objects. It allows for setting, getting, deleting, and merging values at specified paths within an object, ensuring that the original object remains unchanged.

Class: ImmutableUpdater

Constructor

constructor(obj)

Creates a new ImmutableUpdater instance.

• Parameters:
  • obj (Object): The initial object to operate on.

Static Methods

static isObject(value)

Checks if a given value is an object (excluding null).

• Parameters:
  • value (*): The value to check.
• Returns:
  • boolean: True if the value is an object, false otherwise.

static cloneDeep(value)

Recursively clones an object or array.

• Parameters:
  • value (*): The value to clone.
• Returns:
  • *: The cloned value.

static parsePath(path)

Parses a dot-separated path string into an array of keys.

• Parameters:
  • path (string): The path string to parse.
• Returns:
  • Array: An array of keys parsed from the path.
• Throws:
  • Error: If the path is not a non-empty string.

Instance Methods

set(path, value)

Sets a value at a specified path in the object and returns a new ImmutableUpdater instance with the updated object.

• Parameters:
  • path (string): The path where to set the value.
  • value (*): The value to set at the specified path.
• Returns:
  • ImmutableUpdater: A new ImmutableUpdater instance with the updated object.
• Throws:
  • Error: If the path is not a non-empty string or if the path does not exist in the object.

get(path = '')

Retrieves the value at a specified path in the object.

• Parameters:
  • path (string, optional): The path from where to retrieve the value.
• Returns:
  • *: The value at the specified path, or undefined if the path does not exist.
• Throws:
  • Error: If the path is not a non-empty string.

delete(path)

Deletes the property at a specified path in the object and returns a new ImmutableUpdater instance with the updated object.

• Parameters:
  • path (string): The path of the property to delete.
• Returns:
  • ImmutableUpdater: A new ImmutableUpdater instance with the updated object.
• Throws:
  • Error: If the path is not a non-empty string or if the path does not exist in the object.

merge(path, value)

Merges an object into the property at a specified path in the object and returns a new ImmutableUpdater instance with the updated object.

• Parameters:
  • path (string): The path where to merge the object.
  • value (Object): The object to merge at the specified path.
• Returns:
  • ImmutableUpdater: A new ImmutableUpdater instance with the updated object.
• Throws:
  • Error: If the path is not a non-empty string, if the path does not exist in the object, or if value is not an object.

How to Use

Initialization

To use the ImmutableUpdater, create an instance with the initial object:

const initialObject = { a: { b: { c: 42 } } };
const updater = new ImmutableUpdater(initialObject);

Setting a Value

To set a value at a specified path:

const updated = updater.set('a.b.c', 100);
console.log(updated.obj); // { a: { b: { c: 100 } } }

Getting a Value

To get a value from a specified path:

const value = updater.get('a.b.c');
console.log(value); // 42

Deleting a Property

To delete a property at a specified path:

const updated = updater.delete('a.b.c');
console.log(updated.obj); // { a: { b: {} } }

Merging an Object

To merge an object into the property at a specified path:

const updated = updater.merge('a.b', { d: 50 });
console.log(updated.obj); // { a: { b: { c: 42, d: 50 } } }

Error Handling

The methods in ImmutableUpdater will throw errors under certain conditions:

• If the path is not a non-empty string.
• If the specified path does not exist in the object.
• If the value to merge is not an object.

Make sure to handle these errors appropriately in your application.