build.js

import fs from 'node:fs/promises'
import fetch from 'node-fetch'
import {tsvParse} from 'd3-dsv'

const response = await fetch(
  'https://api.github.com/repos/fnielsen/afinn/contents/afinn/data/AFINN-en-165.txt',
  {headers: {'User-Agent': 'request', Accept: 'application/vnd.github.v3.raw'}}
)

const text = await response.text()

/** @type {Record<string, number>} */
const data = {}
const rows = tsvParse('key\tvalue\n' + text)
let index = -1

while (++index < rows.length) {
  const {key, value} = rows[index]
  if (!key) throw new Error('Expected key in `' + rows[index] + '`')
  if (!value) throw new Error('Expected value in `' + rows[index] + '`')
  data[key] = Number.parseInt(value, 10)
}

await fs.writeFile(
  'index.js',
  [
    '/**\n * AFINN 165.\n *\n * @type {Record<string, number>}\n */',
    'export const afinn165 = ' + JSON.stringify(data, null, 2),
    ''
  ].join('\n')
)