Repo Fixtures

Create a small, inspectable real Git repository when a developer tool breaks on staged changes, renames, conflicts, Unicode paths or submodules. Share the scenario command and fixture.json instead of a private working repository.

Dependency-free JavaScript ESM. Requires Git 2.28+ and Node 24.8+; use the latest Node 24 LTS patch. No model API key, network connection or agent client is needed to create a fixture after installation.

Try it

git clone https://github.com/hexmillionaire/repo-fixtures.git
cd repo-fixtures
node bin/repo-fixtures.mjs list
node bin/repo-fixtures.mjs create conflict ../my-conflict --json
git -C ../my-conflict/repo status

The destination must not exist, and its parent must exist. Quote paths with spaces. Successful creation produces a repo/ Git repository, fixture.json, an empty hooks/config directory, and CREATED.txt. A failure leaves INCOMPLETE.txt and partial files for inspection. This tool never removes directories, cleans your worktree, executes an agent, launches another application or downloads a submodule.

GitHub release archives are independently installable:

npm install -g https://github.com/hexmillionaire/repo-fixtures/releases/download/v0.1.0/hexmillionaire-repo-fixtures-0.1.0.tgz
repo-fixtures create staged ./my-staged-fixture --json

Scenarios

| ID | Actual state | | --- | --- | | clean | One committed source file; no changes | | dirty | Unstaged modification, untracked path with a space, ignored cache | | staged | Different index and worktree versions of the same file | | rename | Staged rename into a path with a space | | conflict | Unresolved merge and three-stage index entries | | unusual-paths | Modified and untracked Unicode paths with spaces | | submodule | Committed gitlink pointing to a locally created sibling upstream |

fixture.json version 1 contains the generator version, scenario, relative repository path, initial base commit, independently specified expectations and observed Git status/conflicts/submodules. The CLI's JSON result also includes absolute output paths for local use. Review a report before posting it if those paths are private.

Index/worktree status characters are Git porcelain v1 values. Renames include from. The initial base is intentionally before scenario changes; observations.head records the final HEAD. Submodule paths are recorded even when the top-level status is clean. See a connected scope-audit example.

Library

import { createFixture, listScenarios } from '@hexmillionaire/repo-fixtures';
const result = await createFixture('dirty', './new-fixture');
console.log(result.repository, result.manifest.expectations);

createFixture(scenario, destination, {signal} = {}) returns {directory, repository, manifest}. An abort stops active Git work and leaves a marked partial directory if creation already started. listScenarios() returns fresh {id, description} records. Public report shapes are versioned; the pre-1.0 API can evolve in minor releases. CLI exits 0 on success and 2 for invalid input or creation errors.

Limits and alternatives

This is a compact bug-report bundle generator. It is not a model benchmark, security sandbox, proof of test correctness, repository capture tool or a configurable scenario DSL. A completed fixture should still be verified by the consuming tool. Git author dates and SHA-1 object format are fixed; byte-for-byte bundles are not promised across Git versions and platforms. Keep the submodule bundle at its original location because its generated local URL refers to the sibling upstream directory.

git-scenarios already provides a rich composable DSL, many more scenarios, mocks, runner adapters and a CLI. Choose it for custom histories and broad test-suite integration. Repo Fixtures offers seven intentionally small scenarios, no runtime dependencies, a separate expected/observed JSON manifest and no tool launching or cleanup feature. Both can help agents and humans reproduce Git behavior; neither verifies an agent's claims.

Contribute

Run npm test and npm run test:package. CI runs real Git fixtures on Linux, Windows and macOS plus minimum Node 24.8. Start with CONTRIBUTING.md: useful contributions include a minimized failing fixture, portable Git observations, clearer diagnostics and documentation. Include Git/Node/OS versions and fictional data in reports.

Related: Agent Lanes, Agent Desk, Agent Lanes MCP, MCP Surface.