@soll/jest

Jest integration for soll — scope test runs to only the files affected by a set of changed files.

Prerequisites: Install soll and run soll diagnose --write in your project first.

Quick start (preset)

The easiest way to use @soll/jest is via the preset. Install it and add a single line to your Jest config:

npm install --save-dev @soll/jest

// jest.config.json
{
  "preset": "@soll/jest"
}

That's it. Jest will automatically:

• Read tsconfig.json to discover source files
• Compute changed files via git merge-base diff against the default branch
• Filter test runs to only affected tests
• In watch mode, re-filter on each file change

Architecture

Sits in the packages/ layer of the soll workspace. Consumes the native addon produced by crates/napi/ (via require) and exposes a pure-TypeScript API that returns Jest-compatible filter patterns (--testPathPattern, --testNamePattern).

packages/jest/
  src/
    index.ts               # public API: SollConfig → AffectedTestResult
    file-granularity.ts    # file-level scoping (pattern building, result shaping)
    git.ts                 # git merge-base diff helpers
    discovery.ts           # tsconfig-based source file discovery
    sequencer.ts           # custom TestSequencer (filters to affected files)
    watch-plugin.ts        # watch mode plugin (shouldRunTestSuite hook)
    jest-preset.ts         # preset config wiring sequencer + watch plugin
    __tests__/             # unit tests for each module
  jest-preset.js           # root-level preset entry point

Preset components

| Component | What it does | | ------------------------------------ | -------------------------------------------------------------------------------- | | Sequencer (sequencer.ts) | Extends @jest/test-sequencer to filter sort() results to affected test files | | Watch plugin (watch-plugin.ts) | Implements shouldRunTestSuite hook; caches affected set per run | | Preset (jest-preset.ts) | Wires sequencer + watch plugin into Jest config |

Running all tests

To bypass soll filtering and run every test:

jest --all          # disables sequencer filtering
jest --watchAll     # disables watch plugin filtering

Programmatic API

For custom integrations that need more control than the preset provides:

import { getAffectedTests } from "@soll/jest";

const result = getAffectedTests({
  root: process.cwd(),
  include: await glob("**/*.ts"),
  changedFiles: ["src/logger.ts"],
});

// Pass to Jest:
// jest --testPathPattern <result.testPathPattern>

Exports

| Specifier | Description | | ------------------------- | ------------------------------------- | | @soll/jest | Programmatic API (getAffectedTests) | | @soll/jest/sequencer | Custom TestSequencer class | | @soll/jest/watch-plugin | Watch mode plugin | | @soll/jest/jest-preset | Preset configuration object |

Development

pnpm install         # install dependencies
pnpm build           # compile TypeScript
pnpm test            # run unit tests
pnpm typecheck       # type-check without emitting