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Flint-Docs

Introduction to Flint

Flint is a testing framework for Minecraft servers. It consists of four main components:

  • Flint Core - A Rust library that defines the test format and provides the execution engine
  • FlintCLI - A command-line tool that runs tests against live Minecraft servers (black-box testing)
  • Flint-Steel - The Flint adapter for SteelMC enabling white-box testing
  • FlintBench - The official test collection for validating vanilla Minecraft behavior

With a declarative JSON format, server implementations can be tested deterministically and reproducibly.

What is Flint?

Section titled “What is Flint?”

Flint provides:

  • Declarative test format - Tests are defined in JSON, not code
  • Timeline-based execution - Actions execute at specific game ticks
  • Server-agnostic - Flint defines the format, servers provide the implementation
  • Tag-based organization - Tests can be categorized and filtered
  • Multiple output formats - JSON, TAP, JUnit XML, or human-readable output

Core Concepts

Section titled “Core Concepts”

Test Specifications

Section titled “Test Specifications”

Each test is a JSON file containing:

  • A cleanup region where all actions take place
  • A timeline with actions (block placements, player interactions, assertions)
  • Optional player configuration for inventory tests
  • Tags for organization

Timeline Execution

Section titled “Timeline Execution”

Tests run tick by tick:

  1. Actions for the current tick are executed
  2. The game tick is executed (do_tick)
  3. Assertions verify the expected state

This guarantees deterministic, reproducible results.

Next Steps

Section titled “Next Steps”