Suspect, a simple unit testing module with support for a custom output handler. Includes bonus/optional asserts.lua

asserts.lua

local assert    = assert
local tostring  = tostring
local pcall     = pcall

local FORMAT_ASSERT_EQUALS  = 'expected %s to be equal to %s'
local FORMAT_ASSERT_UNEQ    = 'all values are %s'

asserteq = function(...)
	local values = {...}
	local first  = values[1]
	local i = 2
	repeat
		if first ~= values[i] then error(FORMAT_ASSERT_EQUALS:format(tostring(first),tostring(values[i]))) end
		i=i+1
	until not values[i]
end

assertnoteq = function(...)
	local values = {...}
	local first  = values[1]
	local i = 2
	repeat
		if first ~= values[i] then 
			return
		end
		i=i+1
	until not values[i]
	error(FORMAT_ASSERT_UNEQ:format(tostring(first))) 
end

asserttruthy = function(v)
	assert(v,'value is '..tostring(v))
end

asserttrue = function(v)
	assert(v == true,'value is '..tostring(v))
end

assertfalsy = function(v)
	assert(not v,'value is '..tostring(v))
end

assertfalse = function(v)
	assert(v == false,'value is '..tostring(v))
end

asserterror = function(func)
	assert(not pcall(func),'function ran without an error')
end

results.txt

6 TESTS, 5 PASSED, 1 FAILED

1        P     dummy test
2        P     previous test contains correct description/passed/errormessage
3        F     fail with error message
4        P     have an error message from previous test
5        P     return a string from getresults
6        P     Previous string: 4 TESTS, 3 PASSED, 1 FAILED

TEST 3: fail with error message
.\asserts.lua:12: expected 1 to be equal to 2
stack traceback:
	[C]: in function 'error'
	.\asserts.lua:12: in function 'asserteq'
	test_suspect.lua:14: in function <test_suspect.lua:13>
	[C]: in function 'xpcall'
	.\suspect.lua:81: in function 'assert'
	test_suspect.lua:13: in main chunk
	[C]: ?

suspect.lua

--[[
USAGE:
	suspect.assert(description,func)
	suspect.assert('pass',function() t = 1+1 end)
	suspect.assert('fail',function() t = nil+1 end)
	suspect.clear() // clear all test results
	
	boolean:  omitTraceback
	string:   filename
	string:   results
	
	results = suspect.getresults(omitTraceback)
	suspect.write(filename,omitTraceback)
	suspect.print(omitTraceback)
	
	pass (results,...) to custom output handler
--]]

-- specify a different output handler
local OUTPUT_HANDLER      = nil
local FORMAT_TITLE        = '%s'
local FORMAT_SUMMARY      = '%s TESTS, %s PASSED, %s FAILED'
local FORMAT_TEST_RESULT  = '%-8s %-5s %s'
local FORMAT_ERROR_MSG    = 'TEST %s: %s\n%s' 
local DEFAULT_TITLE       = 'UNIT TEST'

local insert = table.insert
local concat = table.concat

local gettraceback = function(errormessage)
	return errormessage..debug.traceback('',2)
end

-- ==========================
-- OUTPUT HANDLER
-- ==========================
-- string:  results.description
-- string:  results.errormessage
-- boolean: results.passed
-- ...:     optional parameters

local function output(results,...)
	local messages = {}
	local errors   = {}
	local passed_counter = 0
	local omitTraceback  = ...
	local total_tests    = #results
	for i = 1,total_tests do
		local passed        = results[i].passed
		local errormessage  = results[i].errormessage
		local description   = results[i].description
		if passed then passed_counter = passed_counter+1 end
		insert(messages,FORMAT_TEST_RESULT:format(i,passed and 'P' or 'F',description))
		if errormessage and not omitTraceback then insert(errors,FORMAT_ERROR_MSG:format(i,description,errormessage)) end
	end
	insert(messages,1,FORMAT_SUMMARY:format(total_tests,passed_counter,total_tests-passed_counter))
	insert(messages,2,'')
	if #errors > 0 then
		insert(messages,'')
		local errormessages = concat(errors,'\n\n')
		insert(messages,errormessages)
	end
	return concat(messages,'\n')
end

-- ==========================
-- MODULE
-- ==========================
if OUTPUT_HANDLER then output = OUTPUT_HANDLER end

local suspect = 
{
	tests  = {},
}

function suspect.clear()
	suspect.tests = {}
end

function suspect.assert(description,func)
	local passed,errormessage = xpcall(func,gettraceback)
	local test        = {}
	test.description  = description
	test.passed       = passed 
	test.errormessage = errormessage
	insert(suspect.tests,test)
	return passed,errormessage
end

-- pass ... to output handler
function suspect.print(...)
	print(suspect.getresults(...))
end

function suspect.getresults(...)
	return output(suspect.tests,...)
end

function suspect.write(filename,...)
	local file,err = io.open(filename,'w')
	assert(file,err)
	file:write(suspect.getresults(...))
	file:close()
end

return suspect

test_suspect.lua

local suspect = require 'suspect'
require 'asserts'

local s = suspect
s.assert('dummy test',function()
end)
s.assert('previous test contains correct description/passed/errormessage',function()
	local test = s.tests[1]
	asserteq(test.description,'dummy test')
	asserttrue(test.passed)
	assertfalsy(test.errormessage)
end)
s.assert('fail with error message',function()
	asserteq(1,2)
end)
s.assert('have an error message from previous test',function()
	local test = s.tests[3]
	asserttruthy(test.errormessage)
	assertfalsy(test.passed)
end)
local results
s.assert('return a string from getresults',function()
	results = s.getresults()
	asserteq(type(results),'string')
end)
s.assert('Previous string: 4 TESTS, 3 PASSED, 1 FAILED',function()
	asserttruthy(results:match('4 TESTS, 3 PASSED, 1 FAILED'))
end)

s.print(true)