AGENTS.md

This is the standard library for MoonBit.

Refactoring tips

• MoonBit code is organized in block style, each block is separated by ///|, the order of each block is irrelevant. In some refactorings, you can process block by block independently.

• Try to keep deprecated blocks in file called deprecated.mbt in each directory.

• moon fmt is used to format your code properly.

• moon info is used to update the generated interface of the package, each package has a generated interface file .mbti, it is a brief formal description of the package. If nothing in .mbti changes, this means your change does not bring the visible changes to the external package users, it is typically a safe refactoring.

• So in the last step, you typically run moon info && moon fmt to update the interface and format the code. You also check the diffs of .mbti file to see if the changes are expected.

• You should run moon test to check the test is passed. MoonBit supports snapshot testing, so in some cases, your changes indeed change the behavior of the code, you should run moon test --update to update the snapshot.

• You can run moon check to check the code is linted correctly.

• MoonBit packages are organized per directory, for each directory, there is a package.json file listing its dependencies. Each package has its files and blackbox test files (common, ending in _test.mbt) and whitebox test files (ending in _wbtest.mbt).

• In the toplevel directory, this is a moon.mod.json file listing about the module and some meta information.

• When writing tests, you are encouraged to use inspect and run moon test --update to update the snapshots, only use assertions like assert_eq when you are in some loops where each snapshot may vary. You can use moon coverage analyze > uncovered.log to see which parts of your code are not covered by tests.

• agent-todo.md has some small tasks that are easy for AI to pick up, agent is welcome to finish the tasks and check the box when you are done