build-feature

# Build a feature ## 1. Read the closest existing feature Find the command most like the one you are building and read it with its test: `src/commands/status/set.ts` for a write with `--json` and `--full`, `src/commands/inbox.ts` for a list, `src/commands/msg/delete.ts` for a destructive write behind `--yes`. For a new command or subcommand, `add-command` is the checklist of every file to touch. Read the rules in `AGENTS.md`. Done when you can name the file you will copy patterns from. ## 2. Settle decisions in one round List what the request leaves open: command and flag names (consistent verbs and flags across entities), positional argument or named flag, the human and `--json` output, error codes, `--dry-run` and `--yes`, behaviour under a read-only token, and whether private channels change the answer. Ask the owner all of them at once, each with your recommendation. Don't ask what the code can answer. Done when every decision has an answer. ## 3. Write "done" as checkable behaviours Write each behaviour as a command and the expected result, for example: "`tdc msg delete 200 --yes` calls `deleteMessage('200')` and prints `Message 200 deleted.`". Each becomes a test. Done when a test could pass or fail on every one. ## 4. Build in thin slices, test first For each behaviour: write its test at the public interface (`program.parseAsync(['node', 'tdc', ...])`), see it fail, make it pass, run its test file. Follow `write-tests`. Done when every behaviour from step 3 has a passing test you saw fail. ## 5. Update everything the change touches | You changed | Also update | | ---------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------- | | A command, subcommand or flag | `SKILL_CONTENT` in `src/lib/skills/content.ts`, then `npm run sync:skill` | | Called a new SDK method | `API_SPINNER_MESSAGES` in `src/lib/api.ts`; a read-only one goes in `KNOWN_SAFE_API_METHODS` (`src/lib/permissions.ts`) | | A mutating command | `--json` through `MutationOptions` (`src/lib/options.ts`) and `formatJson()`, as "JSON output on mutating commands" in `AGENTS.md` says | | Output that uses colour or symbols | An `--accessible` alternative (`isAccessible()` from `src/lib/global-args.ts`); never an id and a name told apart by colour alone | | A new error code | The `ErrorCode` type in `src/lib/errors.ts` | | Structure (new folder or helper) | `CODEBASE.md` | Done when each row that applies is handled. ## 6. Verify and report Follow `verify`. If the feature needs restructuring first, do that as a separate change with `refactor`.