Import ZSH history to Fish

import_zsh_history_to_fish.js

'use strict';

const fs = require('fs');
const expandHomeDir = require('expand-home-dir');

const zshHistoryRaw = fs.readFileSync(expandHomeDir('~/.zsh_history'), 'utf8');
const zshHistoryLines = zshHistoryRaw.split('\n');

const transformLine = line => {
    try {
        const semicolonIndex = line.indexOf(';');
        const command = line.substring(semicolonIndex + 1);
        const when = line.substring(0, semicolonIndex).split(':')[1].trim();

        return `- cmd: ${command}\n  when: ${when}`;
    } catch (e) {

        // Probably a continuation of the previous line.
        // I don't care about these
    }
};

const fishHistory = zshHistoryLines.map(line => transformLine(line)).join('\n');

fs.writeFileSync(expandHomeDir('~/.config/fish/fish_history'), fishHistory, 'utf8');

It works.