presenter/CLAUDE.md

presenter

Shared Go library for GraphQL error presentation with coded errors.

Shared Documentation

@../docs/claude/architecture.md @../docs/claude/go-services.md @../docs/claude/graphql.md @../docs/claude/conventions.md

Library Information

Purpose

Provides a standardized GraphQL error presenter that handles coded errors across all microservices. Converts internal error codes to GraphQL error extensions.

Usage

import "gitea.unbound.se/shiny/presenter"

// Create error presenter with valid codes and entities
errorPresenter := presenter.New(logger, validCodes, validEntities, internalErrorCode)

// Use in gqlgen server config
srv := handler.NewDefaultServer(generated.NewExecutableSchema(cfg))
srv.SetErrorPresenter(errorPresenter)

Key Types

• CodedError - Error type with code, entity, and params
• Code - Error code type
• Entity - Error entity type

Error Extensions

Errors are presented with extensions:

• code - The error code (mapped to valid codes or internal error)
• errorEntity - The entity related to the error (optional)
• params - Additional error parameters (optional)