#rollback code explainers

typescript

import { Component, inject, signal } from '@angular/core';
import { CdkDragDrop, DragDropModule, moveItemInArray } from '@angular/cdk/drag-drop';
import { HttpClient } from '@angular/common/http';
import { finalize } from 'rxjs';

Drag-and-drop reordering with signals in Angular

drag-and-drop signals optimistic-update

Intermediate 8 steps

python

import os
import shutil
import tempfile
from contextlib import contextmanager

Transactional file operations in Python

transactions rollback closures

Intermediate 8 steps

typescript

import { useState, useCallback } from 'react';
 
type Todo = {
  id: string;

Optimistic UI updates in a React hook

optimistic-updates custom-hooks error-handling

Intermediate 8 steps

rust

pub struct ScopeGuard<F: FnMut()> {
    rollback: F,
    active: bool,
}

A RAII rollback guard in Rust

raii error-handling closures

Advanced 8 steps

ruby

module FileResource
  # Opens a file, yields it to the caller, and guarantees the
  # handle is closed even if the block raises an exception.
  def self.open(path, mode = "r")

Guaranteeing cleanup with begin/ensure in Ruby

resource-management exception-safety blocks

Intermediate 8 steps