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Typescript environmet variables, the right way

Ludovico Russo

lettura in 2 minuti

Typescript has been a huge introduction in the JS world, this language allows to have all the benefit of javascript and the benefit of typed languages at the same time.

For me, it is really important since it was the technology that convinced me to start work in nodejs and in web technology seriously (I come from static typed languages such as C++).

Working on complex typescript project with lot's of configurations coming from environment variables, I was looking for a good typescript library that allowed me to manage configurations over env variables with the power of typescript.

Unfortunatly, after some research, I wasn't able to find a library that was able to satisfy me need. So I start implementing a very simple one with the following goals:

1. Allow me to configure with a simple object expected environment varaible names,
2. Allow me to specify the expected type of the configuration,
3. Panic if variable is not found or the contained values does not match confiured type.

env-ts-conf

env-ts-conf is a simple typescript library that satisfy my need.

You can define a simple configuration object as following

import { getConfigs } from "env-ts-conf";

const config = getConfigs({
test: {
type: "string",
variableName: "TEST_VARIABLE",
default: "test",
},
myNumber: {
type: "number",
variableName: "MY_NUMBER",
},
});


and get back a typed object config with the following interface:

interface Config {
test: string;
myNumber: number;
}


Features

1. Simple to use
2. Configuration output is typed
3. Supports number, string and boolean
4. Supports default values,