flint-steel

Flint testing framework integration for SteelMC. This crate implements the Flint traits (FlintAdapter, FlintWorld, FlintPlayer) so that automated Minecraft tests run against the real SteelMC server logic — no mocks, 100% code reuse with production behavior.

What This Crate Provides

• A SteelAdapter implementation for Flint's test runner
• A SteelTestWorld backed by the real steel-core world with RAM-only storage
• A SteelTestPlayer that drives real inventory, item, and block interaction code
• Test helpers for running JSON Flint specs from SteelBenchmark
• Failure links for opening test failures in flint-viz

How It Works

flint-steel wraps real steel-core internals in lightweight test harnesses:

• SteelTestWorld — wraps an Arc<World> with RAM-only storage and on-demand empty chunks (no disk I/O)
• SteelTestPlayer — uses real inventory, item, and block behavior with a mock network connection that records packets
• SteelAdapter — creates test worlds and drives the Flint test runner

Tests are written as JSON specs (see SteelBenchmark) and executed against the real game engine, including block neighbors, shapes, callbacks, and tick processing.

Discord

Join the Flint Discord to discuss this project or ask questions.

Prerequisites

• Rust (edition 2024)
• Git
• SteelBenchmark test specs

steel-core, steel-protocol, steel-registry, steel-utils, and flint-core are Cargo git dependencies and are resolved automatically during the build.

Installation

git clone https://github.com/FlintTestMC/flint-steel.git
cd flint-steel
cargo test --lib test_world_creation

For a full first run, continue with GETTING_STARTED.md.

Getting Tests

Clone SteelBenchmark to provide the test files:

git clone https://github.com/FlintTestMC/SteelBenchmark.git test

By default, tests are loaded from ./test. You can change this with the TEST_PATH environment variable.

You can also copy the example Flint config:

cp flint.toml.example flint.toml

Usage

# Run all Flint tests
cargo test --lib

# Run a single test by name
FLINT_TEST=place_fence cargo test --lib

# Run tests matching a glob pattern
FLINT_PATTERN="*fence" cargo test --lib

# Run tests filtered by tags
FLINT_TAGS=redstone,walls cargo test --lib

Environment Variables

Variable	Default	Description
FLINT_TEST	—	Run a single test by exact name
FLINT_PATTERN	—	Run tests matching a glob pattern
FLINT_TAGS	—	Filter tests by comma-separated tags
TEST_PATH	./test	Path to test files directory
FLINT_VIZ_URL	http://localhost:7878	Base URL used when printing flint-viz links for failures; overrides TOML

You can set these in a .env file. flint.toml supports persistent test filtering:

viz_url = "http://localhost:7878"

[filter]
implemented_only = true

[filter.tags]
redstone = true
walls = false

Environment variables take priority over flint.toml. The viz URL can be set in TOML as viz_url, flint_viz_url, or FLINT_VIZ_URL.

Documentation

• GETTING_STARTED.md - first-run setup and common commands
• CONTRIBUTING.md - development workflow and contribution guidelines

Related Projects

Project	Description
SteelMC	SteelMC server implementation
flint-core	Flint testing framework
SteelBenchmark	Test suite and benchmark specs
FlintCLI	Command-line interface for Flint
FlintDocs	Documentation

License

MIT