Sample

Jest requires setupFilesAfterEnv rather than setupFiles to register test framework lifecycle hooks and custom matchers because setupFiles runs before the test framework is installed

sha256:54d7455a1f1a8164920b91e0674efab285e8709ffd5ea541dc3da0dd5f541e20

Case

Goal

Jest requires setupFilesAfterEnv rather than setupFiles to register test framework lifecycle hooks and custom matchers because setupFiles runs before the test framework is installed HOW

Packages

jest 29.7.0

Environment

node

Created

2026-08-17T01:53:57Z

Commonly assumed

A test setup file configured under setupFiles has access to test framework globals like beforeEach, afterEach, and expect.extend.

The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.

Contract

• assert running Jest with test framework hooks in setupFiles fails with ReferenceError: beforeEach is not defined because the framework environment is not yet initialized
• assert setupFiles executes in the isolated test environment before the test framework and can configure environment globals
• assert setupFilesAfterEnv executes after test framework initialization, allowing beforeEach hooks and expect.extend matchers to run across test suites
• assert jest-config normalize correctly resolves <rootDir> tokens for both setupFiles and setupFilesAfterEnv into absolute paths

Files

• NOTES.md
• csx.json
• fixtures/jest.invalid-setup.json
• fixtures/jest.valid.json
• fixtures/sample.test.js
• fixtures/setup-after-env.js
• fixtures/setup-env.js
• fixtures/setup-hook-error.js
• package-lock.json
• package.json
• test/contract.mjs

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

csx-seed

Verification receipts

• node 22 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17 · ed25519:d91480838ac982c9