Parse Fluent files to TypeScript definitions

main.rs

use anyhow::{anyhow, Result};
use std::fs;

fn main() -> Result<()> {
    let args: Vec<String> = std::env::args().collect();

    if args.len() <= 1 {
        return Err(anyhow!("No file specified"));
    }

    let filename = &args[1];
    let file = fs::read_to_string(filename).expect("Unable to read file");

    let translation_keys = file
        .lines()
        .filter(|line| !line.is_empty())
        // Remove indented lines, terms, and comments
        .filter(|line| !line.starts_with([' ', '-', '#']))
        .filter_map(|line| line.split_once(" = "))
        .map(|(key, _)| key)
        .collect::<Vec<_>>();

    let mut output = String::new();

    output.push_str("export type TranslationKey =\n");

    for key in translation_keys {
        output.push_str(&format!("\t| '{key}'\n"));
    }

    // write output to file
    fs::write("output.ts", output)?;

    Ok(())
}