Schema-Driven Code Generator Challenge

Goal

Build a code generator that reads JSON Schema files and produces Go type definitions.

Setup

Requires Go 1.23+.

• schemas/ contains JSON Schema files describing three types: Product, Category, and Article.
• testdata/ contains JSON payloads that conform to these schemas.
• model/ is where your generated Go code should go. It ships with stub types so that the project compiles.
• harness_test.go imports the types from model/ and unmarshals each payload into the corresponding type.

Your Task

Write a code generator that reads the schemas in schemas/ and produces Go types in model/. The generator can be a script, a CLI or just a library, it's up to you. What matters is that the output faithfully represents the schema. This means:

• Each named type from the JSON schema should have a Go equivalent
• Each field in the JSON schema should have a Go equivalent (not necessarily 1-to-1)
• Whether or not a field is optional should be encoded in the Go types in some manner
• We also need a Go representation of concepts such as oneOf

The test harness (go test) is a basic smoke test which unmarshals payloads into your types and checks for errors. It's possible to make all tests pass even though the generated Go code is still missing a lot of necessary information.

Rules

• Use any tools you want, including LLMs.
• The generated types must live in the model package.
• The type names must match the schema titles: Product, Category, Article.
• You may add any additional types as needed (sub-structs, enums, unions, etc.).

What to deliver

• A private fork or copy of this repository with your solution
• A README covering: how to run the generator, what decisions you made and why
• Brief notes for a walkthrough — how you approached it, what trade-offs you made

Time

Aim for about 3 hours. It's fine to leave things out — just tell us what you'd add with more time.