@spikedpunch/cbd-jest

The Jest adapter for CBD. A custom test environment records per-test coverage windows, and a config helper turns a selection into Jest's own name filter.

Install

pnpm add -D @spikedpunch/cbd-jest jest-environment-node @spikedpunch/cbd @spikedpunch/cbd-cli

Peer dependencies: jest >=29 <31 and jest-environment-node >=29 <31. Validated on Jest 29.6 and 30.5.

Setup

// jest.config.cjs
const { withCbd } = require('@spikedpunch/cbd-jest/config')

module.exports = withCbd({
  testEnvironment: '@spikedpunch/cbd-jest/environment',
})

• testEnvironment records windows (one environment and one shard per test file).
• withCbd applies CBD_SELECTION as an anchored testNamePattern. Without it, recording still works but the run is not narrowed. Without CBD_SELECTION the config is returned unchanged.

Both can live in a committed config: with CBD_SHARD and CBD_SELECTION unset they are inert.

Recording and selecting

pnpm exec cbd collect -- pnpm jest
pnpm exec cbd select

cbd collect sets CBD_SHARD and CBD_COMMIT for the run (and CBD_SELECTION for a subset), then builds the map.

Jest creates one environment per test file, and setup() is awaited before the file is evaluated, so the file's imports land in @load and teardown() writes the footer. Windows are the awaited test_start / test_done events. Identity is the enclosing describe names plus the test name, with Jest's synthetic ROOT_DESCRIBE_BLOCK omitted.

Why selection lives in the config

Jest's testNamePattern is the only filter that sees a fully expanded test name, including test.each / describe.each rows. The config is loaded before the run, which is early enough to read the selection file. A setup-file wrapper cannot do this: .each rows bypass it, and silently skipping a selected row is the failure CBD does not accept. Titles are escaped and joined into one alternation (> becomes whitespace), anchored so Should throw does not also match Should throw 2.

Notes

• Test identity is the suite path plus the test name; same-named tests in different describe blocks stay distinct.
• Statically skipped and todo tests open no window.
• A failed test's window does not enter the map.
• Jest's own --coverage must be off during a collection.

See CBD.md for the model and the root README for the CLI and config.