@rigelbuild/tabit

Define Zod-backed TypeScript configuration and render deterministic JSON with Bun.

Pronounced TAH-bit. Named for the star π3 Ori, "the enduring one".

Install with bun add @rigelbuild/tabit.

Define a config module

import { defineConfig } from "@rigelbuild/tabit";
import { z } from "zod";

const Settings = z.strictObject({ service: z.string(), retries: z.int().default(3) });
export default defineConfig(Settings, () => ({ service: "worker" }), {
  out: "./settings.json",
  schemaOut: "./settings.schema.json",
});

The module filename ends in .config.ts. Config objects should use z.strictObject or an explicitly open object schema. Rendering rejects unclosed object schemas, transforms, intersections, and values that JSON cannot represent. It also rejects schema types that JSON Schema cannot represent: dates, bigints, maps, functions, and undefined.

Render and check

tabit [--check] [<dir>...]

The command searches the current directory recursively for config modules. It skips dot directories and node_modules, and selects files with runtime imports from this package; type-only imports and exports do not count. Pass directories to limit the search. tabit writes JSON and optional JSON Schema files beside each module. tabit --check compares the expected bytes without writing.

The exit code is 0 when rendering succeeds or every output is current, 1 for an invalid config or stale output, and 2 for invalid command usage.

Tests

Import expectCommitted and renderForSnapshot from @rigelbuild/tabit/testing to check rendered files or collect output for snapshots. Paths may be absolute or resolved against the caller's current working directory. expectCommitted reports missing output files with their paths.