Исходники [1.0.1] watchman - runtime argument/type/rule checker

[Riveriks]

watchman — это простая и гибкая библиотека для проверки типов и задания контрактов в Lua во время выполнения. Помогает писать более надёжный код, отлавливая ошибки на этапе выполнения с понятными сообщениями.
Проверка типов: number, string, table и другие
Объединения типов: string|number
Опциональные типы: (number)? — значение или nil
Любой тип: ?, любой не-nil: !
Пользовательские условия: number; $ > 0
Правила для конкретных типов: ?; <number>: $ >= 0; <string>: #$ > 0
Поддержка watchman.test, assert, check, и contract
Поддержка Lua методов: работает как и на object:method(...), так и на object.method(object, ...)
Можно расширять: своя логика определения типов (например, для ООП-систем)
Пример использования:
Lua:
local watchman = require("watchman")

-- Basic typecheck.
print("Basic typecheck:", watchman.test(1, "number")) -- Basic typecheck: true

-- Failed basic typecheck.
print("Failed typecheck:", watchman.test(1, "string")) -- Failed typecheck: false, string expected, got number

-- Accept any type.
print("Any type:", watchman.test(1, "?")) -- Any type: true

-- Accept any but not nil.
print("Not nil:", watchman.test(nil, "!")) -- Not nil: false, any not nil type expected, got nil

-- Typeunions.
print("Typeunions:", watchman.test({}, "string|number")) -- Typeunions: false string or number expected, got table

-- Optional typeunions.
print("Optional typeunions:", watchman.test({}, "(string|number)?")) -- Optional typeunions: false string or number or no value expected, got table

-- Custom user-rules.
-- User rules starts after first semicolon.
-- $ means '0' in this case.
print("Custom user-rule:", watchman.test(0, "number; $ > 0")) -- Custom user-rule: false failed check '$ > 0'

-- Multiple user-rules.
-- Or you can write it one rule using and, or, not keywords like basic Lua code.
print("Multiple user-rules:", watchman.test(0, "number; $ > 0; $ < 64")) -- Multiple user-rules: false failed checks '$ > 0', '$ < 64'

-- User rules for specific types.
-- '<...>:' means 'perform this rule for this type'.
print("Type-specific rules:", watchman.test("", "?; <number>: $ >= 0; <string>: #$ > 0")) -- Type-specific rules: false failed check '#$ > 0'

--- Assertions.
watchman.assert(1, "number") -- Same as all above, but throws error on fail, also adds 'assertion failed:' prefix to error message.

--- Multiple args checks.
watchman.check(1, "number", "", "string", {}, "table") -- Same as test, but throws error on fail, also adds 'bad argument #<arg number>:' prefix to error mesasge.

--- Function contracts.
local function sum(a, b)
-- Same as test, but throws error on fail, automatically adds function arguments from stack using 'debug' builtin table, also formats message like 'bad argument '<argname>' to function '<funcname>' (<error>)'.
-- Don't works on varargs.
-- Rules count must match arguments count, otherwise error.

-- Why it's named 'contract'?:
-- Answer: Contract assertions (since C++26) - cppreference.com
-- Watchman's contract not that powerful like C++ contracts, but why not lol.
watchman.contract("number", "number")
return a + b
end

print("Sum:", sum(2, 4)) -- 6
-- nil because of pcall and we on main scope.
print("Sum (must fail):", pcall(sum, "", nil)) -- false, bad argument 'a' to function 'nil' (number expected, got string)

-- Custom checks.
local env = require("watchman.env")

-- You can spoof watchman's type function. By default it is builtin 'type' function.
env.type = function(v)
local typeof = type(v)
if typeof == "table" then
return v.__typename or typeof -- For your class system, other purposes...
end
return typeof
end

-- Also you can spoof watchman's 'istype' function.
env.istype = function(v, typeof)
return env.type(v) == typeof -- Default function.
end

-- Perform check on that bro.
do
local T = { __typename = "Person", age = 19 }
print("Custom checks:", watchman.test(T, "Person; $.age > 18")) -- true
end

-- Watchman in methods.
do
local T = {}

function T.foo(self, a, b)
watchman.contract("number", "number")
end

function T:baz(a, b)
watchman.contract("number", "number")

-- Also can check self if needed.
watchman.contract("table", "number", "number")
end

-- Handle boths variants.
T.foo(T, 1, 2)
T:baz(1, 2)
end
Установка:
1. Зайти на GitHub Releases.
2. Скачать watchman.lua последней доступной версии.
3. Установить себе в проект / в папку moonloader/lib
GitHub: click​