TypeScript Lab: Comma List Parser

LAB / EXPLORATION

TypeScript Lab: Comma List Parser

Planned

LAB 106 — Validation & Safety
Convert comma-separated text into a clean string array.

LAB TypeScript Lab: Comma List Parser Preview coming soon

LAB 106

TypeScript Lab: Comma List Parser

Concept

Parsing splits, trims, and removes empty values from user input.

Concept

Parsing splits, trims, and removes empty values from user input.

Objective & Explanation

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

Learning Target

Objective

Convert comma-separated text into a clean string array.

Explanation

Parsing splits, trims, and removes empty values from user input.

Project Plan

Structure, technologies, data boundary, and source connection.

Structure

project/
├── package.json
├── tsconfig.json
├── index.html
├── styles.css
└── src/
    └── app.ts

Technologies

TypeScript
HTML
CSS

Data Layer

No persistent data layer. Keep all demonstration values inside the standalone project.

Sandbox Source

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

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

Change one input and observe the visible output change.

Code & Configuration

Starter configuration plus the focused implementation example.

Focused TypeScript

Implement this behavior first, then alter the input.

function parseStringList(value: unknown): string[] {
  return String(value ?? "")
    .split(",")
    .map(item => item.trim())
    .filter(Boolean);
}

Starter Configuration

Keep the project independently buildable.

package.json

{
  "type": "module",
  "scripts": { "build": "tsc" },
  "devDependencies": { "typescript": "^7.0.2" }
}

tsconfig.json

{
  "compilerOptions": {
    "rootDir": "./src",
    "outDir": "./dist",
    "target": "ES2022",
    "module": "ES2022",
    "lib": ["ES2022", "DOM"],
    "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: convert comma-separated text into a clean string array.

Data: None