TypeScript Lab: Atomic Reorder

LAB / EXPLORATION

Planned

LAB 114 — Database Transactions
Reorder multiple values and roll everything back on failure.

LAB TypeScript Lab: Atomic Reorder Preview coming soon

LAB 114

TypeScript Lab: Atomic Reorder

Concept

Atomic transactions prevent half-completed multi-step ordering changes.

Concept

Atomic transactions prevent half-completed multi-step ordering changes.

Objective & Explanation

What the project should make visible and why the concept matters.

Learning Target

Objective

Reorder multiple values and roll everything back on failure.

Explanation

Atomic transactions prevent half-completed multi-step ordering changes.

Project Plan

Structure, technologies, data boundary, and source connection.

Structure

project/
├── package.json
├── tsconfig.json
├── index.html
├── styles.css
├── data/
│   └── learning.db
└── src/
    ├── client.ts
    └── server.ts

Technologies

TypeScript
Node.js
SQLite
HTML
CSS

Data Layer

Use SQLite learning rows. Isolate destructive practice from important Sandbox records.

Sandbox Source

src/local-editor/server.ts → reorderNode()

Build Instructions

Build only the focused behavior, then use the visual layer to inspect it.

Setup

Create the standalone project folder and listed files.

Implement

Implement the smallest version that demonstrates the concept.

Run & Inspect

Render the returned or changed data in the browser.

Code & Configuration

Starter configuration plus the focused implementation example.

Focused TypeScript

Implement this behavior first, then alter the input.

database.exec("BEGIN;");
try {
  normalizeSiblingOrder(recordId, parentId);
  swapRows(current, target);
  normalizeSiblingOrder(recordId, parentId);
  database.exec("COMMIT;");
} catch (error) {
  database.exec("ROLLBACK;");
  throw error;
}

Starter Configuration

Keep the project independently buildable.

package.json

{
  "type": "module",
  "scripts": {
    "build": "tsc",
    "start": "npm run build && node --enable-source-maps dist/server.js"
  },
  "devDependencies": {
    "@types/node": "^26.4.0",
    "typescript": "^7.0.2"
  }
}

tsconfig.json

{
  "compilerOptions": {
    "rootDir": "./src",
    "outDir": "./dist",
    "target": "ES2022",
    "module": "ES2022",
    "lib": ["ES2022", "DOM"],
    "types": ["node"],
    "strict": true,
    "sourceMap": true
  },
  "include": ["src/**/*.ts"]
}

Expected Visual Result

The output is the proof that the concept is working.

Visible Proof

The browser should visibly demonstrate: reorder multiple values and roll everything back on failure.

Data: SQLite