update-changelog.js

const fs = require("fs");
const PromisePool = require("@supercharge/promise-pool");

const { git, getOriginalCommit } = require("./scripts/changelog-generator");

const gitDir = "/Users/eloy/Code/ReactNative/react-native/.git"
const seen = new Map()
const SHAs = new Set()

const existingChangelogData = fs.readFileSync("./CHANGELOG.md", "utf8");

function forEachSHA(cb) {
    return existingChangelogData.replace(/[a-f0-9]{7,40}/g, sha => {
        return cb(sha);
    })
}

forEachSHA(sha => {
    SHAs.add(sha.slice(0, 7));
    return sha;
})

const pool = new PromisePool({ concurrency: 20, items: Array.from(SHAs) })
pool.process(sha => {
    if (seen.get(sha)) {
        return null;
    }
    return git(gitDir, "log", "--format=%B", "-n", "1", sha).then(message => {
        return getOriginalCommit(gitDir, { sha, commit: { message: message.trimRight() } }).then(resolved => {
            seen.set(sha.slice(0, 7), resolved.sha.slice(0, 7));
            return null;
        })
    })
}).then(({ errors }) => {
    for (const e of errors) {
        console.error(e)
    }

    const newData = forEachSHA(sha => {
        const resolved = seen.get(sha.slice(0, 7))
        if (resolved) {
            return resolved.slice(0, sha.length);
        } else {
            console.log(sha)
            return sha;
        }
    })

    fs.writeFileSync("./CHANGELOG.md", newData, "utf8");
})