Project Agents.md Guide#

This is a MoonBit project.

You can browse and install extra skills here:
https://github.com/moonbitlang/skills

Project Structure#

• MoonBit packages are organized per directory; each directory contains a

moon.pkg file listing its dependencies. Each package has its files and
blackbox test files (ending in _test.mbt) and whitebox test files (ending in
_wbtest.mbt).

• In the toplevel directory, there is a moon.mod.json file listing module

metadata.

Coding convention#

• 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.

Tooling#

• moon fmt is used to format your code properly.
• moon ide provides project navigation helpers like peek-def, outline, and

find-references. See $moonbit-agent-guide for details.

• 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.

• In the last step, run moon info && moon fmt to update the interface and

format the code. Check the diffs of .mbti file to see if the changes are
expected.

• Run moon test to check tests pass. MoonBit supports snapshot testing; when

changes affect outputs, run moon test --update to refresh snapshots.

• Prefer assert_eq or assert_true(pattern is Pattern(...)) for results that

are stable or very unlikely to change. Use snapshot tests to record current
behavior. For solid, well-defined results (e.g. scientific computations),
prefer assertion tests. You can use moon coverage analyze > uncovered.log to
see which parts of your code are not covered by tests.