Minecraft Test Environment

Test Environment

Test environments are the world test environments in which test instances run. Java Edition only.

Definition Format

Registry TEST_ENVIRONMENT, data pack path test_environment (files in data/<namespace>/test_environment/; tags in tags/test_environment/).

type one of:

• all_of — runs all definitions (recursive list, by ID or inline) on enter/exit in order.
• clock_time — sets a world clock to time (≥0) on enter, restores on exit.
• difficulty — sets the world difficulty (peaceful/easy/normal/hard) on enter, restores on exit (even when locked).
• function — runs setup / teardown functions on enter/exit.
• game_rules — sets rules (game rule ID → value) on enter, restores on exit.
• timeline_attributes — adds timelines (IDs) to the server environment attributes on enter, removes on exit.
• weather — sets weather (clear/rain/thunder, each 100000 ticks) on enter, restores the cycle on exit.

Behavior

Definitions load once at server startup (restart required). Every test instance must run inside its environment. Tests run in batches; a batch shares one environment. When a batch finishes, the game checks whether the next batch's environment is identical (same environment object, not equal contents): if not, it exits the old and enters the new; if identical, it continues without switching. After the last batch, the game exits the last-entered environment.