Files
bible/rules/patterns/go-code-style/contract.md
Michael Chus 0005f3e41a Compress always-on contracts and restore pagination fields
The always-on set is paid by every session, so it gets the tightest
form: git-sync-check shrinks to its procedural core, testing-policy
moves the table-test example to README.md and folds the agent
instructions into the rules, go-code-style inlines the error-wrapping
example. Per-session read cost drops from 403 to 336 lines.

Also restore the pagination response fields in table-management: the
previous dedup replaced them with a reference to go-api, which the
table router line does not load.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-06-12 10:05:00 +03:00

3.1 KiB

Contract: Go Code Style and Project Conventions

Version: 1.3

Source Text and Comments

  • Use plain ASCII in source code and comments by default.
  • Do not use em dash, emoji, or other decorative Unicode markers in code, comments, log messages, or user-facing fallback strings unless a feature explicitly requires non-ASCII text.
  • Do not leave AI-style markers in the codebase: ornamental phrasing, assistant-like filler, synthetic enthusiasm, or comments that read like generated prose instead of technical documentation.
  • Comments must be short, concrete, and technical. Explain intent, invariants, or non-obvious constraints; do not write marketing-style or conversational commentary.

Logging

See the go-logging contract for full rules.

Summary: use slog, log to stdout/stderr (binary console), never to browser console.

Error Handling

  • Always wrap errors with context: fmt.Errorf("save component %s: %w", record.ID, err). A bare return err loses context.
  • Never silently discard errors with _ in production paths.
  • Return errors up the call stack; log at the handler/task boundary, not deep in service code.

Code Formatting

  • Always run gofmt before committing. No exceptions.
  • No manual alignment of struct fields or variable assignments.

HTTP Handler Structure

Handlers are thin. Business logic belongs in a service layer.

Handler -> validates input, calls service, writes response
Service -> business logic, calls repository
Repository -> SQL queries only, returns domain types
  • Handlers must not contain SQL queries.
  • Services must not write HTTP responses.
  • Repositories must not contain business rules.

Startup Sequence (Go web app)

1. Parse flags / load config
2. Connect to DB; fail fast if unavailable (see go-database contract)
3. Run migrations
4. Initialize services and background workers
5. Register routes
6. Start HTTP server

Never reverse steps 2 and 5. Never start serving before migrations complete.

Configuration

  • Config lives in a single config.yaml file, not scattered env vars.
  • Env vars may override config values but must be documented.
  • Never hardcode ports, DSNs, or file paths in application code.
  • Provide a config.example.yaml committed to the repo.
  • The actual config.yaml is gitignored.
  • Secret handling and pre-commit/pre-push leak checks must follow the secret-management contract.

Template / UI Rendering

  • Server-rendered HTML via Go templates is the default.
  • htmx for partial updates; no full SPA framework unless explicitly decided.
  • Template errors must return 500 and log the error server-side.
  • Never expose raw Go error messages to the end user in rendered HTML.

Business Logic Placement

  • Threshold computation, status derivation, and scoring live on the server.
  • The UI only reflects what the server returns; it does not recompute status client-side.
  • Example: "critical / warning / ok" badge color is determined by the handler, not by JS.

Dependency Rules

  • Prefer standard library. Add a dependency only when the stdlib alternative is significantly worse.
  • Document the reason for each non-stdlib dependency in a comment or ADL entry.