dev on golang, notes, etc

golang-env.ts

/*
 * Covert Goland env to .env format
 * e.g.
 * Let's say we have env `ENV=production` and `DB=some-db-url` configured in Golang. It will be the following format when it is copiled from the conf.
 * ENV=production;DB=some-db-url
 * But the popular env format `.env` use the following format:
 * ENV=production
 * DB=some-db-url
 */

const envStr = 'ENV=production;DB=some-db-url'

class EnvHub {
    private envs: Map<string,string>
    constructor() {
        this.envs = new Map()
    }
    load(env: string) {
        const regExp = /([^;\s]+)=([^;\s]+)/ig 
        if (!regExp.test(envStr)) {
            throw new Error("invalid env string")
        }
        
        this.envs = Array.from(envStr.matchAll(regExp)).reduce((a, c) => {
            a.set(c[1], c[2])
            return a
        }, new Map<string, string>())
    }
    set(k: string, v: string) {
        return this.envs.set(k, v)
    }
    get(k: string) {
       return this.envs.get(k)
    }
    delete(k: string) {
        return this.envs.delete(k)
    }
    toDotEnv() {
        const list: string[] = []
        for (const [key, value] of this.envs) {
            list.push(`${key}=${value}`)
        }
        return list.join('\n')
    }
}

var hub = new EnvHub()
try {
    hub.load(envStr)    
    console.log(hub.toDotEnv())
} catch (err) {
    console.error(err)
}