Many Javascript developers have added typescript to their projects in the last few years. But how many of them are sure of their types at runtime? Can types be guaranteed on runtime too?
Using Zod that can be realized! Let's see together how we can use Zod to improve the awareness of our code during its execution and prevent strange mistakes or a bad user experience.

In this talk, I want to show how we can use Zod to guarantee the type in a React Application at runtime. Environment variables, HTTP requests, forms and so on could create troubles in our applications, mainly if they contain unexpected types. Using Zod, we can create schemas to guarantee the types expected in our editor at runtime. In this way, we can react quickly when an environment variable misses or when someone changes the API contract without informing us.
A small validation layer in our applications can prevent a bad user experience and notify us immediately, so we can fix the problem as soon as possible and mitigate the visualization of wrong data.

In this speech, I'll talk about the benefit of using GraphQL and show a small demo of an endpoint created with Fastify Mercurius and Prisma.