Typing end to end with TypeScript

Tricks and tooling for web applications typing with TypeScript.

About me

• OSS dev
• CTO @DiagRAMS
• blogging
• ecologist/activist

Why using TypeScript?

• less bugs
• autocompletion
• security
• type checks
• better abstractions

Still some issues

What about managing IOs ?

• API interface
• database IOs
• user inputs
• routing parameters
• configuration/environment

API interface

OpenAPI, JSONSchema and GraphQL to the rescue!

OpenAPI

Syncing API documentation with the code:

• using Whook,
• using Express.

GraphQL

Tie TypeScript types with GraphQL schemas:

• using graphql-codegen,
• using TypeGraphQL.

Others

Did you heard about tRPC?

JSONSchema

Only JSON inputs?

• generate types from JSONSchema using schema2dts
  and validate with AJV,
• create schemas and types altogether with TypeBox.

What about clients?

Applications and back-ends may use your API too:

• type casting using generics,
• generate sdk from OpenAPI,
• type GraphQL queries using graphql-codegen, again.

Database

• using generics,
• using ODM/ORMs: pgtyped, typeorm,
• parsing SQL queries (wip)

User inputs

Typing React forms entries with useForm.

Routing parameters

Let's manage NextJS query/path parameters!

Configuration/Environment

Use global types

Thanks!

Any question?