api base url resolver

Infers a url based on a current url, for instance, allows a front end to resolve a back-end api base url depending on it's running environment.

Its very useful when running a lot of environment stages and the front-end must match the back-end environment

Installation

To install this package use npm install api-base-url-resolver

Usage

subDomainResolver(origin: string, subDomain: string, options?: Options): string;

• origin : current domain, mostly location.hostname
• subDomain : the desired domain, mostly api subdomain is used
• options :
  • replace : replaces the sub-domain to the provided one
  • protocol : changes the protocol
  • conditions : if there some specific condition to a specific env or url, useful for localhost developments envs
  • envVar : when provided, it will look for this env var and use it as url. useful for localhost developments envs or specific deploys like canary or beta

Usage examples

import apiBaseUrlResolver from "api-base-url-resolver";

apiBaseUrlResolver("https://domain.com", "api"); // => "https://api.domain.com"

apiBaseUrlResolver("http://domain.com", "api"); // => "http://api.domain.com"

apiBaseUrlResolver("https://env.domain.com", "api"); // => "https://api.env.domain.com"

apiBaseUrlResolver("https://some.other.app.env.domain.com", "api"); // => "https://api.some.other.app.env.domain.com"

apiBaseUrlResolver("http://domain.com", "api", { protocol: "https" }); // => "https://api.domain.com"

apiBaseUrlResolver("https://domain.com", "api", { protocol: "http" }); // => "http://api.domain.com"

apiBaseUrlResolver("https://app.env.domain.com", "api", { replace: true }); // => "https://api.env.domain.com"

apiBaseUrlResolver("https://app.other.env.domain.com", "api", { replace: true }); // => "https://api.other.env.domain.com"

const conditions = {
    "localhost:8080": "https://custom.env.custom.com",
    "localhost:8081": "http://localhost:8080"
};

subDomainResolver("localhost:8080", "api", { conditions }); // => "https://custom.env.custom.com"
subDomainResolver("localhost:8081", "api", { conditions }); // => "http://localhost:8080"

const envVar = "MAIN_API";
process.env.MAIN_API = "https://env-var-defined-url.com";

subDomainResolver("localhost:8080", "api", { envVar }); // => "https://env-var-defined-url.com"
subDomainResolver("localhost:8081", "api", { envVar }); // => "https://env-var-defined-url.com"
subDomainResolver("https://otherDomain.com", "api", { envVar }); // => "https://env-var-defined-url.com"