Module:UnitTests
-- UnitTester provides unit testing for other Lua scripts. For details see [[Wikipedia:Lua#Unit_testing]].
 -- For user documentation see talk page.
 local UnitTester = {}
 
 local frame, tick, cross
 local result_table_header = &quot;{|class=\&quot;wikitable\&quot;\n|+ %s\n! !! Text !! Expected !! Actual&quot;
 local result_table_live_sandbox_header = &quot;{|class=\&quot;wikitable\&quot;\n|+ %s\n! !! Test !! Live !! Sandbox  !! Expected&quot;
 
 local result_table = { n = 0 }
 local result_table_mt = {
 	insert = function (self, ...)
 		local n = self.n
 		for i = 1, select('#', ...) do
 			local val = select(i, ...)
 			if val ~= nil then
 				n = n + 1
 				self[n] = val
 			end
 		end
 		self.n = n
 	end,
 	insert_format = function (self, ...)
 		self:insert(string.format(...))
 	end,
 	concat = table.concat
 }
 result_table_mt.__index = result_table_mt
 setmetatable(result_table, result_table_mt)
 
 local num_failures = 0
 
 function first_difference(s1, s2)
     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 return_varargs(...)
 	return ...
 end
 
 function UnitTester:preprocess_equals(text, expected, options)
     local actual = frame:preprocess(text)
     if actual == expected then
         result_table:insert('| ', tick)
     else
         result_table:insert('| ', cross)
         num_failures = num_failures + 1
     end
     local maybe_nowiki = (options and options.nowiki) and mw.text.nowiki or return_varargs
     local differs_at = self.differs_at and (' \n| ' .. first_difference(expected, actual)) or ''
     result_table:insert(' \n| ', mw.text.nowiki(text), ' \n| ',
     	maybe_nowiki(expected), ' \n| ', maybe_nowiki(actual), differs_at,
     	&quot;\n|-\n&quot;)
 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 = frame:preprocess(text1)										-- &lt;actual&gt; and &lt;expected&gt; will be rendered in &lt;result_table&gt;
 	local expected = frame:preprocess(text2)
 	local actual_for_comp = actual												-- copy of &lt;actual&gt; that may be modified to have same templatestyles stripmarker as &lt;expected&gt; for comparison
 	local highlight																-- boolean true to highlight mismatched renderings in Actual column of result
 
 	if options and true == options.templatestyles then							-- when module rendering has templatestyles strip markers, use ID from expected to prevent false test fail
 		local pattern = '(\127[^\127]*UNIQ%-%-templatestyles%-)(%x+)(%-QINU[^\127]*\127)'	-- templatestyle stripmarker pattern
 		local _, expected_stripmarker_id = expected:match(pattern)				-- get templatestyles strip marker id from expected (the reference); ignore first capture in pattern
 
 		if expected_stripmarker_id then
 			actual_for_comp = actual_for_comp:gsub(pattern, '%1' .. expected_stripmarker_id .. '%3')	-- replace actual id with expected id; ignore second capture in pattern
 		end
 	end
 
 	-- option to ignore any strip marker when comparing actual to expected
 	if options and true == options.stripmarker then
 		local pattern = '(\127[^\127]*UNIQ%-%-%l+%-)(%x+)(%-%-?QINU[^\127]*\127)'
 		local _, expected_stripmarker_id = expected:match(pattern)
 		if expected_stripmarker_id then
 			actual_for_comp = actual_for_comp:gsub(pattern, '%1' .. expected_stripmarker_id .. '%3')
 			expected = expected:gsub(pattern, '%1' .. expected_stripmarker_id .. '%3')
 		end
 	end
 
 	if actual_for_comp == expected then											-- are the renderings the same
 		result_table:insert('| ', tick)
 	else
 		result_table:insert('| ', cross)										-- nope; mark as failure
 		num_failures = num_failures + 1											-- tally
 		highlight=true															-- and highlight the results table Actual column cell (so the failed test is more obvious)
 	end
 	local maybe_nowiki = (options and options.nowiki) and mw.text.nowiki or return_varargs
 	local differs_at = self.differs_at and (' \n| ' .. first_difference(expected, actual)) or ''
 	result_table:insert(' \n| ',
 		mw.text.nowiki(text1),													-- the tested template nowikied
 		' \n| ',
 		maybe_nowiki(expected),													-- the expected version
 		highlight and ' \n|style=&quot;background: #fc0;&quot;| ' or ' \n| ',				-- highlighted if test fail; not else
 		maybe_nowiki(actual), differs_at,										-- the actual rendering using its own template styles if that is an option
 		&quot;\n|-\n&quot;)
 end
 
 function UnitTester:preprocess_equals_compare(live, sandbox, expected, options)
 	local live_text = frame:preprocess(live)
 	local sandbox_text = frame:preprocess(sandbox)
 
 	local highlight_live = false
 	local highlight_sandbox = false
 	if live_text == expected and sandbox_text == expected then
 		result_table:insert('| ', tick)
 	else
 		result_table:insert('| ', cross)
 		num_failures = num_failures + 1
 
 		if live_text ~= expected then
 			highlight_live = true
 		end
 
 		if sandbox_text ~= expected then
 			highlight_sandbox = true
 		end
 	end
     local maybe_nowiki = (options and options.nowiki) and mw.text.nowiki or return_varargs
     local differs_at = self.differs_at and (' \n| ' .. first_difference(expected, live_text) or first_difference(expected, sandbox_text)) or ''
     result_table:insert(
 			' \n| ',
 			mw.text.nowiki(live),
 			highlight_live and ' \n|style=&quot;background: #fc0;&quot;| ' or ' \n| ',
 			maybe_nowiki(live_text),
 			highlight_sandbox and ' \n|style=&quot;background: #fc0;&quot;| ' or ' \n| ',
 			maybe_nowiki(sandbox_text),
 			' \n| ',
 			maybe_nowiki(expected),
 			differs_at,
 			&quot;\n|-\n&quot;
 	)
 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:preprocess_equals_sandbox_many(module, function_name, cases, options)
     for _, case in ipairs(cases) do
 		local live = module .. &quot;|&quot; .. function_name .. &quot;|&quot; .. case[1] .. &quot;}}&quot;
 		local sandbox = module .. &quot;/sandbox|&quot; .. function_name .. &quot;|&quot; .. case[1] .. &quot;}}&quot;
         self:preprocess_equals_compare(live, sandbox, case[2], options)
     end
 end
 
 function UnitTester:equals(name, actual, expected, options)
     if actual == expected then
         result_table:insert('| ', tick)
     else
         result_table:insert('| ', cross)
         num_failures = num_failures + 1
     end
     local maybe_nowiki = (options and options.nowiki) and mw.text.nowiki or return_varargs
     local differs_at = self.differs_at and (' \n| ' .. first_difference(expected, actual)) or ''
     local display = options and options.display or function(x) return x end
     result_table:insert(' \n| ', name, ' \n| ',
     	maybe_nowiki(tostring(display(expected))), ' \n| ',
     	maybe_nowiki(tostring(display(actual))), differs_at, &quot;\n|-\n&quot;)
 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 val_to_str(v)
     if type(v) == 'string' then
         v = mw.ustring.gsub(v, '\n', '\\n')
         if mw.ustring.match(mw.ustring.gsub(v, '[^\'&quot;]', ''), '^&quot;+$') then
             return &quot;'&quot; .. v .. &quot;'&quot;
         end
         return '&quot;' .. mw.ustring.gsub(v, '&quot;', '\\&quot;' ) .. '&quot;'
     else
         return type(v) == 'table' and table_to_str(v) or tostring(v)
     end
 end
 
 function table_key_to_str(k)
     if type(k) == 'string' and mw.ustring.match(k, '^[_%a][_%a%d]*$') then
         return k
     else
         return '[' .. val_to_str(k) .. ']'
     end
 end
 
 function table_to_str(tbl)
     local result, done = {}, {}
     for k, v in ipairs(tbl) do
         table.insert(result, val_to_str(v))
         done[k] = true
     end
     for k, v in pairs(tbl) do
         if not done[k] then
             table.insert(result, table_key_to_str(k) .. '=' .. val_to_str(v))
         end
     end
     return '{' .. table.concat(result, ',') .. '}'
 end
 
 function UnitTester:equals_deep(name, actual, expected, options)
     if deep_compare(actual, expected) then
         result_table:insert('| ', tick)
     else
         result_table:insert('| ', cross)
         num_failures = num_failures + 1
     end
     local maybe_nowiki = (options and options.nowiki) and mw.text.nowiki or return_varargs
     local actual_str = val_to_str(actual)
     local expected_str = val_to_str(expected)
     local differs_at = self.differs_at and (' \n| ' .. first_difference(expected_str, actual_str)) or ''
     result_table:insert(' \n| ', name, ' \n| ', maybe_nowiki(expected_str),
     	' \n| ', maybe_nowiki(actual_str), differs_at, &quot;\n|-\n&quot;)
 end
 
 function UnitTester:iterate(examples, func)
 	require 'libraryUtil'.checkType('iterate', 1, examples, 'table')
 	if type(func) == 'string' then
 		func = self[func]
 	elseif type(func) ~= 'function' then
 		error((&quot;bad argument #2 to 'iterate' (expected function or string, got %s)&quot;)
 			:format(type(func)), 2)
 	end
 
 	for i, example in ipairs(examples) do
 		if type(example) == 'table' then
 			func(self, unpack(example))
 		elseif type(example) == 'string' then
 			self:heading(example)
 		else
 			error(('bad example #%d (expected table, got %s)')
 				:format(i, type(example)), 2)
 		end
 	end
 end
 
 function UnitTester:heading(text)
 	result_table:insert_format(' ! colspan=&quot;%u&quot; style=&quot;text-align: left&quot; | %s \n |- \n ',
 		self.columns, text)
 end
 
 function UnitTester:run(frame_arg)
     frame = frame_arg
     self.frame = frame
     self.differs_at = frame.args['differs_at']
     tick = frame:preprocess('{{Tick}}')
     cross = frame:preprocess('{{Cross}}')
 
 	local table_header = result_table_header
 	if frame.args['live_sandbox'] then
 		table_header = result_table_live_sandbox_header
 	end
 
 	self.columns = 4
     if self.differs_at then
         table_header = table_header .. ' !! Differs at'
         self.columns = self.columns + 1
     end
 
     -- Sort results into alphabetical order.
     local self_sorted = {}
     for key, _ in pairs(self) do
         if key:find('^test') then
             table.insert(self_sorted, key)
         end
     end
     table.sort(self_sorted)
     -- Add results to the results table.
     for _, value in ipairs(self_sorted) do
         result_table:insert_format(table_header .. &quot;\n|-\n&quot;, value)
         self[value](self)
         result_table:insert(&quot;|}\n&quot;)
     end
 
     return (num_failures == 0 and &quot;&lt;b style=\&quot;color:#008000\&quot;&gt;All tests passed.&lt;/b&gt;&quot; or &quot;&lt;b style=\&quot;color:#800000\&quot;&gt;&quot; .. num_failures .. &quot; tests failed.&lt;/b&gt;[[Category:Failed Lua testcases using Module:UnitTests]]&quot;) .. &quot;\n\n&quot; .. frame:preprocess(result_table:concat())
 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