local test = require 'u-test'

-- You can use 'assert' to check invariants.
test.hello_world = function ()
    test.assert(true)
    test.assert(1 ~= 2)
end

-- This is how you can create your first test case
test.addition = function ()
    test.equal(1 + 1, 2)
    test.not_equal("1 + 1", "2")
    test.almost_equal(1 + 1, 2.1, 0.2)
end

-- You can enable custom start_up and tear_down actions
-- Thse actions will be invoked:
-- start_up - before test case
-- tear_down - after test case
local global_state = 0
test.start_up = function () global_state = 1 end
test.tear_down = function () global_state = 0 end

test.dummy1 = function()
    test.equal(global_state, 1)
    test.is_number(global_state)
end

-- You can separate tests by test suites
test.string.format = function ()
    test.equal(string.format("%d + %d", 1, 1), "1 + 1")
    test.not_equal(string.format("Sparky %s", "bark"), "Fluffy bark")
end

test.string.find = function ()
    test.is_nil(string.find("u-test", "banana"))
    test.is_not_nil(string.find("u-test", "u"))
end

-- You can declare test case with parameters
test.string.starts_with = function (str, prefix)
    test.equal(string.find(str, prefix), 1)
end

-- Then, run it with multiple parameters
test.string.starts_with("Lua rocks", "Lua")
test.string.starts_with("Wow", "Wow")

local global_table = {}

-- Each test suite can be customized by start_up and tear_down
test.table.start_up = function ()
    global_table = { 1, 2, "three", 4, "five" }
end
test.table.tear_down = function ()
    global_table = {}
end

test.table.concat = function ()
    test.equal(table.concat(global_table, ", "), "1, 2, three, 4, five")
end

-- you can disable broken test case like this
test.broken.skip = true
test.broken.bad_case = function ()
    test.equal(1, 2)
    there_is_no_such_function()
end

-- obtain total number of tests and numer of failed tests
local ntests, nfailed = test.result()

-- this code prints tests summary and invokes os.exit with 0 or 1
test.summary()

test.assert(true)
test.equal(1, 1)
test.not_equal(1, 2)
test.is_false(false)
test.is_true(true)
test.is_not_nil("Something")
test.is_nil(nil)
test.is_boolean(true)
test.is_boolean(false)
test.is_string("I am string! look at me!")
test.is_number(3)
test.is_table({"I am table now"})
test.is_function(function () end)
test.is_userdata(userdata_value)
test.error_raised(function() error("error 10") end, "error 10")

local function is_elephant(animal)
    if animal ~= "elephant" then
        local failure_msg = "Expected elephant, but got "..tostring(animal)
        return false, msg
    end

    return true
end

test.register_assert("is_elephant", is_elephant)

test.is_elephant("dolphin") -- fails!