Working with TOML

TypeScript:
Working with TOML

How to:

First, you’ll need a TOML parser. @iarna/toml is a popular choice. Install it with npm: npm install @iarna/toml --save. Here’s how you read a TOML file and parse it to a JavaScript object:

import * as fs from 'fs';
import toml from '@iarna/toml';

const tomlContent = fs.readFileSync('config.toml', 'utf-8');
const parsedData = toml.parse(tomlContent);

console.log(parsedData);

If config.toml contains:

[server]
port = 8080

The output would be:

{ server: { port: 8080 } }

And, writing to a TOML file is just as straightforward:

import * as fs from 'fs';
import { stringify } from '@iarna/toml';

const obj = { server: { port: 8080 } };
const tomlString = stringify(obj);
fs.writeFileSync('config.toml', tomlString);

Running this code writes the object to config.toml in TOML format.

Deep Dive

TOML was created by Tom Preston-Werner, the co-founder of GitHub, around 2013 as a response to the limitations he perceived in other formats like INI or YAML. It’s designed to be unambiguous and easy to parse into data structures, hence, a favorite for configuration files. Alternatives like JSON lack comments, while YAML is more complex. TOML shines in its simplicity and its ability to clearly represent complex data hierarchies.

Under the hood, when you parse TOML in TypeScript, you’re converting textual data into a structured format the language can manipulate. This involves lexing (turning raw text into tokens) and parsing (building an internal data structure); @iarna/toml handles both seamlessly. The emoji support is a fun touch, showing TOML’s user-centric approach.

TypeScript:Working with TOML

How to:

Deep Dive

See Also

TypeScript:
Working with TOML