How to use environment variable in Typescript properly?

Question

I'm trying to make a simple api using typescript and when I use any env variable I get an error from TS compiler Tells me that this could be undefined

example

// Not Working

const db = process.env.DB_URL   // This gives an error that the result could be a string or undefined

to fix this I have to make a type guard and check with if statement as follows

const db = process.env.DB_URL   

if (db){
  // ....
}

Is there a better approach to to such a thing instead of explicitly check for every variable ?

Yes, using a conditional check provides both type safety and runtime safety. — jsejcksn, Sep 28 '21 at 06:27

score 1 · Answer 1 · answered Sep 28 '21 at 06:11

1

You can apply null check and keep it as string instead of defining two types:

const db: string = process.env.DB_URL ?? ''

// empty strings are falsy/falsey
if (db) { // do this}
else { //do this}

answered Sep 28 '21 at 06:11

Apoorva Chikara

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2

this what I'm doing for now ,and my question is there a better approach ? – Islam Hanafi Mahmoud Sep 28 '21 at 06:25
1

This is a better approach, you are doing both here type safety and runtime safety. – Apoorva Chikara Sep 28 '21 at 06:59

How to use environment variable in Typescript properly?

1 Answers1