Testing

47.1 busted (BDD-Style)

-- spec/mathx_spec.lua
local mathx = require("mathx")

describe("mathx", function()
    describe("clamp", function()
        it("clamps above the maximum", function()
            assert.are.equal(10, mathx.clamp(15, 0, 10))
        end)
        it("keeps values in range", function()
            assert.equal(5, mathx.clamp(5, 0, 10))
        end)
    end)

    it("doubles numbers", function()
        assert.same({2, 4}, {mathx.double(1), mathx.double(2)})   -- deep equality
    end)

    it("raises on bad input", function()
        assert.has_error(function() mathx.double(nil) end)
    end)

    it("uses spies and stubs", function()
        local s = spy.on(mathx, "double")
        mathx.double(3)
        assert.spy(s).was.called_with(3)
        stub(os, "time").returns(0)
        assert.equal(0, os.time())
        os.time:revert()
    end)

    before_each(function() --[[ setup ]] end)
    after_each(function() --[[ teardown ]] end)
end)

luarocks install busted
busted                       # runs spec/*_spec.lua
busted --coverage && luacov  # coverage via luacov
busted -o TAP                # output formats: utfTerminal, TAP, json, junit

47.2 luaunit (xUnit-Style, Single File)

Other tools: telescope, lust (tiny), gambiarra, plenary.test_harness (Neovim plugins), TestEZ (Roblox).

local lu = require("luaunit")
TestMath = {}
function TestMath:testAdd() lu.assertEquals(1 + 1, 2) end
function TestMath:testError() lu.assertErrorMsgContains("division", function() error("division by zero") end) end
os.exit(lu.LuaUnit.run())