A pure Lua module with no external dependency that provides simple sanity-checks of types for values. It doesn't aim to turn Lua into a typed language or anything fancy, it's just basically the equivalent of the luaL_check... functions in the Lua/C API that you will typically want to have at least on your public functions.

• Canonical repository: https://git.sr.ht/~mna/tcheck
• Issue tracker: https://todo.sr.ht/~mna/tcheck

Via Luarocks:

$ luarocks install tcheck

Or simply copy the single tcheck.lua file in your project or your LUA_PATH.

Assuming local tcheck = require 'tcheck'. You can check out the tests for actual examples of using the API.

Checks that the values conform to the types provided as first argument. The types argument can be a single string for a single value, or an array of strings.

The type string can be any of the type built-in function values, any of the math.type or io.type values, or a value to match with the __name or __type field of the value's metadata.

To support multiple types for a value, the pipe | character is used to separate different type names. As a special case, * can be specified to mean any non-nil value, it cannot be combined with any other type.

Returns the array of type names that did match for each value, or raises an error if a value did not match.

Clone the project and install the required development dependencies:

• luaunit (unit test runner)
• luacov (recommended, test coverage)

If like me you prefer to keep your dependencies locally, per-project, then I recommend using my llrocks wrapper of the luarocks cli, which by default uses a local lua_modules/ tree.

$ llrocks install ...

To run tests:

$ llrocks run test/main.lua

To view code coverage:

$ llrocks cover test/main.lua

The BSD 3-clause license.