Stop writing CLI validation. Parse it right the first time

> Think about it. When you get JSON from an API, you don't just parse it as any and then write a bunch of if-statements. You use something like Zod to parse it directly into the shape you want. Invalid data? The parser rejects it. Done.

Isn’t writing code and using zod the same thing? The difference being who wrote the code.

Of course, you hope zod is robust, tested, supported, extensible, and has docs so you can understand how to express your domain in terms it can help you with. And you hope you don’t have to spend too much time migrating as zod’s api changes.

Yes, both are writing code. But nearly all the time, the constraints you want to express can be expressed with zod, and in that case using zod means you write less code, and the code you do write is more correct.

> Of course, you hope zod is robust, tested, supported, extensible, and has docs so you can understand how to express your domain in terms it can help you with. And you hope you don’t have to spend too much time migrating as zod’s api changes.

Yes, judgement is required to make depending on zod (or any library) worthwhile. This is not different in principle from trusting those same things hold for TypeScript, or Node, or V8, or the C++ compiler V8 was compiled with, or the x86_64 chip it's running on, or the laws of physics.