Purpose

+/-

This module facilitates creating unit tests for Lua modules.

Put the following at Module:name/testcases:

local tests = require('Module:UnitTests')

function tests:test_example()
	--[[ here be the tests ]]
end

return tests

Then put the following on Module:name/testcases/documentation:

{{#invoke:name/testcases|run_tests}}

Tests should be written as Lua methods whose names start with test. The self object contains the following methods, which may be called from the method:

preprocess_equals(text, expected, options)
Will check whether expanding templates in text results in expected.
preprocess_equals_many(prefix, suffix, cases, options)
preprocess_equals_preprocess(text1, text2, options)
Will check whether expanding templates in text1 and text2 results in the same string.
preprocess_equals_preprocess_many(prefix1, suffix1, prefix2, suffix2, cases, options)
equals(name, actual, expected, options)
Will check whether two primitive values are equal. name will be used as the row header. When the value is a table, equals_deep should be used.
equals_deep(name, actual, expected, options)
Will check whether two values, which may be tables, are equal. name will be used as the row header.

options should be given in a table or omitted. Currently, the only option supported is nowiki, which will cause both the expected and the actual values to be wrapped in <nowiki> tags when rendering the results table.


local UnitTester = {}

local frame
local tick, cross =
	'[[File:Yes check.svg|20px|alt=Passed|link=|Test passed]]',
	'[[File:X mark.svg|20px|alt=Failed|link=|Test failed]]'

local result_table_header = '{| class="unit-tests wikitable"\n! class="unit-tests-img-corner" style="cursor:pointer" title="Only failed tests"| !! Text !! Expected !! Actual'
local result_table = {}
local num_failures = 0
local total_tests = 0

local function first_difference(s1, s2)
	if type(s1) ~= 'string' then return 'N/A' end
	if type(s2) ~= 'string' then return 'N/A' end
	if s1 == s2 then return '' end
	local max = math.min(#s1, #s2)
	for i = 1, max do
		if s1:sub(i,i) ~= s2:sub(i,i) then return i end
	end
	return max + 1
end

local function val_to_str(v)
	if type(v) == 'string' then
		v = mw.ustring.gsub(v, '\n', '\\n')
		if mw.ustring.match(mw.ustring.gsub(v, '[^\'"]', ''), '^"+$') then
			return "'" .. v .. "'"
		end
		return '"' .. mw.ustring.gsub(v, '"', '\\"' ) .. '"'
	elseif type(v) == 'table' then
		local result, done = {}, {}
		for k, val in ipairs(v) do
			table.insert(result, val_to_str(val))
			done[k] = true
		end
		for k, val in pairs(v) do
			if not done[k] then
				if (type(k) ~= "string") or not mw.ustring.match(k, '^[_%a][_%a%d]*$') then
					k = '[' .. val_to_str(k) .. ']'
				end
				table.insert(result, k .. '=' .. val_to_str(val))
			end
		end
		return '{' .. table.concat(result, ', ') .. '}'
	else
		return tostring(v)
	end
end

local function deep_compare(t1, t2, ignore_mt)
	local ty1 = type(t1)
	local ty2 = type(t2)
	if ty1 ~= ty2 then return false end
	if ty1 ~= 'table' and ty2 ~= 'table' then return t1 == t2 end
	
	local mt = getmetatable(t1)
	if not ignore_mt and mt and mt.__eq then return t1 == t2 end
	
	for k1, v1 in pairs(t1) do
		local v2 = t2[k1]
		if v2 == nil or not deep_compare(v1, v2) then return false end
	end
	for k2, v2 in pairs(t2) do
		local v1 = t1[k2]
		if v1 == nil or not deep_compare(v1, v2) then return false end
	end

	return true
end

function UnitTester:preprocess_equals(text, expected, options)
	local actual = self.frame:preprocess(text)
	if actual == expected then
		table.insert(result_table, '|- class="unit-test-pass"\n | ' .. tick)
	else
		table.insert(result_table, '|- class="unit-test-fail"\n | ' .. cross)
		num_failures = num_failures + 1
	end
	local differs_at = self.differs_at and (' || ' .. first_difference(expected, actual)) or ''
	actual   = tostring(actual)
	expected = tostring(expected)
	if self.nowiki or options and options.nowiki then
		expected = mw.text.nowiki(expected)
		actual = mw.text.nowiki(actual)
	end
	table.insert(result_table, ' || ' .. mw.text.nowiki(text) .. ' || ' .. expected .. ' || ' .. actual .. differs_at .. "\n")
end

function UnitTester:preprocess_equals_many(prefix, suffix, cases, options)
	for _, case in ipairs(cases) do
		self:preprocess_equals(prefix .. case[1] .. suffix, case[2], options)
	end
end

function UnitTester:preprocess_equals_preprocess(text1, text2, options)
	local actual = self.frame:preprocess(text1)
	local expected = self.frame:preprocess(text2)
	if actual == expected then
		table.insert(result_table, '|- class="unit-test-pass"\n | ' .. tick)
	else
		table.insert(result_table, '|- class="unit-test-fail"\n | ' .. cross)
		num_failures = num_failures + 1
	end
	if self.nowiki or options and options.nowiki then
		expected = mw.text.nowiki(expected)
		actual = mw.text.nowiki(actual)
	end
	local differs_at = self.differs_at and (' || ' .. first_difference(expected, actual)) or ''
	table.insert(result_table, ' || ' .. mw.text.nowiki(text1) .. ' || ' .. expected .. ' || ' .. actual .. differs_at .. "\n")
end

function UnitTester:preprocess_equals_preprocess_many(prefix1, suffix1, prefix2, suffix2, cases, options)
	for _, case in ipairs(cases) do
		self:preprocess_equals_preprocess(prefix1 .. case[1] .. suffix1, prefix2 .. (case[2] and case[2] or case[1]) .. suffix2, options)
	end
end

function UnitTester:equals(name, actual, expected, options)
	if actual == expected then
		table.insert(result_table, '|- class="unit-test-pass"\n | ' .. tick)
	else
		table.insert(result_table, '|- class="unit-test-fail"\n | ' .. cross)
		num_failures = num_failures + 1
	end
	if self.nowiki or options and options.nowiki then
		expected = mw.text.nowiki(expected)
		actual = mw.text.nowiki(actual)
	end
	local differs_at = self.differs_at and (' || ' .. first_difference(expected, actual)) or ''
	if expected == nil then
		expected = '(nil)'
	else
		expected = tostring(expected)
	end
	if actual == nil then
		actual = '(nil)'
	else
		actual = tostring(actual)
	end
	table.insert(result_table, ' || ' .. name .. ' || ' .. expected .. ' || ' .. actual .. differs_at .. "\n")
end

function UnitTester:equals_deep(name, actual, expected, options)
	if deep_compare(actual, expected) then
		table.insert(result_table, '|- class="unit-test-pass"\n | ' .. tick)
	else
		table.insert(result_table, '|- class="unit-test-fail"\n | ' .. cross)
		num_failures = num_failures + 1
	end
	local actual_str = val_to_str(actual)
	local expected_str = val_to_str(expected)
	if self.nowiki or options and options.nowiki then
		expected_str = mw.text.nowiki(expected_str)
		actual_str = mw.text.nowiki(actual_str)
	end
	local differs_at = self.differs_at and (' || ' .. first_difference(expected_str, actual_str)) or ''
	table.insert(result_table, ' || ' .. name .. ' || ' .. expected_str .. ' || ' .. actual_str .. differs_at .. "\n")
end

function UnitTester:run(frame)
	num_failures = 0
	result_table = {}

	self.frame = frame
	self.nowiki = frame.args['nowiki']
	self.differs_at = frame.args['differs_at']
	self.summarize = frame.args['summarize']

	local table_header = result_table_header
	if self.differs_at then
		table_header = table_header .. ' !! Differs at'
	end

	-- Sort results into alphabetical order.
	local self_sorted = {}
	for key, value in pairs(self) do
		if key:find('^test') then
			total_tests = total_tests + 1
			table.insert(self_sorted, key)
		end
	end
	table.sort(self_sorted)
	-- Add results to the results table.
	for _, key in ipairs(self_sorted) do
		table.insert(result_table, table_header .. "\n")
		table.insert(result_table, '|+ style="text-align: left; font-weight: bold;" | ' .. key .. ':\n|-\n')
		local traceback = "(no traceback)"
		local success, mesg = xpcall(function ()
			return self[key](self)	
		end, function (mesg)
			traceback = debug.traceback("", 2)
			return mesg
		end)
		if not success then
			table.insert(result_table, (' |-\n | colspan="%u" style="text-align: left" | <strong class="error">Script error during testing: %s</strong>%s\n'):format(
				self.differs_at and 5 or 4, mw.text.nowiki(mesg), frame:extensionTag("pre", traceback)
			))
			num_failures = num_failures + 1
		end
		table.insert(result_table, "|}\n\n")
	end

	local refresh_link = tostring(mw.uri.fullUrl(mw.title.getCurrentTitle().fullText, 'action=purge&forcelinkupdate'))

	local failure_cat = '[[Category:Failing module unit tests]]'
	if mw.title.getCurrentTitle().text:find("/documentation$") then
		failure_cat = ''
	end
	
	total_tests = (#result_table - 3) / 2
	local num_successes = total_tests - num_failures
	
	if (self.summarize) then
		if (num_failures == 0) then
			return '<strong class="success">' .. total_tests .. '/' .. total_tests .. ' tests passed</strong>'
		else
			return '<strong class="error">' .. num_successes .. '/' .. total_tests .. ' tests passed</strong>'
		end
	else
		return (num_failures == 0 and '<strong class="success">All tests passed.</strong>' or '<strong class="error">' .. num_failures .. ' tests failed.</strong>' .. failure_cat) .. " <span class='plainlinks'>[" .. refresh_link .. " (refresh)]</span>\n\n" .. table.concat(result_table)
	end
end

function UnitTester:new()
	local o = {}
	setmetatable(o, self)
	self.__index = self
	return o
end

local p = UnitTester:new()
function p.run_tests(frame) return p:run(frame) end
return p