Posted on • Originally published atdouglasmoura.dev
Validate your environment variables with Zod
Zod is the most famous validation library in the TypeScript ecosystem. With Zod, you create aschema and validate your data according to the schema. Observe the schema below:
import{z}from'zod'constUserSchema=z.object({name:z.string().min(1),age:z.number({coerce:true}).min(18),email:z.string().email(),})This schema can be used to validate an object as follows:
constdata={name:'John Doe',age:18,email:'john@example.com',}// If there is a validation error, it throws an errorconstvalidatedData=UserSchema.parse(data)// If there is a validation error, it returns an error object for you to handle laterconstsafeValidatedData=UserSchema.safeParse(data)// => { success: false; error: ZodError }// => { success: true; data: 'billie' }Zod is capable of performing various types of validations on your data, so be sure to read thedocumentation for more details.
Validating Environment Variables
We can use Zod to validate the values present inprocess.env and even process them before using the environment variables in our application. Usually, I like to create anenvironment.ts file, as in the example below:
import{z}from'zod'constenvironmentSchema=z.object({// Define the possible values for NODE_ENV, always leaving a default value:NODE_ENV:z.enum(['test','development','production']).default('production'),// Environment variables are always defined as strings. Here, convert the string to a number and set a default value:PORT:z.number({coerce:true}).default(3000),})exportconstenv=environmentSchema.parse(process.env)Then, just import the variable and use it throughout my application:
importFastifyfrom'fastify'import{env}from'./environment.js'constapp=Fastify({logger:true})app.listen({port:env.PORT},(err)=>{if(err){app.log.error(err)process.exit(1)}})Top comments(0)
For further actions, you may consider blocking this person and/orreporting abuse
