Markus Tacker

Pronouns: he/him

Principal R&D Engineer
Nordic Semiconductor
Trondheim, Norway

coderbyheart.com/socials

Book club: REST in Practice

https://restinpractice.com/

https://coderbyheart.com/rest-in-practice-reading-guide

Needs

• Validate incoming data
• Validate outgoing data
• TypeScript
• Third-party endpoint (we cannot use gRPC/tRPC)

Why JSON schema

• Good enough
• Widely known syntax for defining validations
• Can easily be ported to other implementations
• Can be adopted / read by other teams using other languages

Solution: @sinclair/typebox

• JSON Schema based
• In-memory validation
• Fast TypeCompiler (~2x faster than AJV)

Validation basics

Code demo: code/validator/validateWithTypeBox.ts

Best practices

• Re-use and compose
• Add titles, descriptions
• Keep schema open (allow additional properties)

validatingFetch() for JSX

• handle async validation
• nicer syntax

https://github.com/hello-nrfcloud/web/blob/926fb672bdb5fbad5fe1a04f244355d50e3cb5ee/src/utils/validatingFetch.ts#L42

Code demo: code/preact/SIMUsageHistory.tsx

Code organization

• backend ↔︎ proto ↔︎ web

Discussion

Alternatives?

• https://zod.dev/

Thank you