Annexes

Annex A: More on table printing

When asserting tables equality, by default, the table content is printed in case of failures. LuaUnit tries to print tables in a readable format. It is possible to always display the table id along with the content, by setting a module parameter PRINT_TABLE_REF_IN_ERROR_MSG . This helps identifying tables:

local lu = require('luaunit')

local t1 = {1,2,3}
-- normally, t1 is dispalyed as: "{1,2,3}"

-- if setting this:
lu.PRINT_TABLE_REF_IN_ERROR_MSG = true

-- display of table t1 becomes: "<table: 0x29ab56> {1,2,3}"

Note

table loops

When displaying table content, it is possible to encounter loops, if for example two table references eachother. In such cases, LuaUnit display the full table content once, along with the table id, and displays only the table id for the looping reference.

Example: displaying a table with reference loop

local t1 = {}
local t2 = {}
t1.t2 = t2
t1.a = {1,2,3}
t2.t1 = t1

-- when displaying table t1:
--   table t1 inside t2 is only displayed by its id because t1 is already being displayed
--   table t2 is displayed along with its id because it is part of a loop.
-- t1: "<table: 0x29ab56> { a={1,2,3}, t2=<table: 0x27ab23> {t1=<table: 0x29ab56>} }"

Annex B: Comparing tables with keys of type table

There are a few programs out there which use tables as keys for other tables. How to compare such tables is delicate.

A small code block is worth a thousand pictures :

local lu = require('luaunit')

-- let's define two tables
t1 = { 1, 2 }
t2 = { 1, 2 }
lu.assertEquals( t1, t2 ) -- succeeds

-- let's define three tables, with the two above tables as keys
t3 = { t1='a' }
t4 = { t2='a' }
t5 = { t2='a' }

The difference between t3 and t4 is that they both reference a key with different table references but identical table content.

LuaUnit chooses to treat this as two different keys, so t3 and t4 are not considered equal.

lu.assertEquals( t3, t4 ) -- fails

If using the same table as key, they are now considered equal:

lu.assertEquals( t4, t5 ) -- fails

Annex C: Source code of example

Source code of the example used in the Getting started with LuaUnit section

--
-- The examples described in the documentation are below.
--

lu = require('luaunit')

function add(v1,v2)
    -- add positive numbers
    -- return 0 if any of the numbers are 0
    -- error if any of the two numbers are negative
    if v1 < 0 or v2 < 0 then
        error('Can only add positive or null numbers, received '..v1..' and '..v2)
    end
    if v1 == 0 or v2 == 0 then
        return 0
    end
    return v1+v2
end

function adder(v)
    -- return a function that adds v to its argument using add
    function closure( x ) return x+v end
    return closure
end

function div(v1,v2)
    -- divide positive numbers
    -- return 0 if any of the numbers are 0
    -- error if any of the two numbers are negative
    if v1 < 0 or v2 < 0 then
        error('Can only divide positive or null numbers, received '..v1..' and '..v2)
    end
    if v1 == 0 or v2 == 0 then
        return 0
    end
    return v1/v2
end



TestAdd = {}
    function TestAdd:testAddPositive()
        lu.assertEquals(add(1,1),2)
    end

    function TestAdd:testAddZero()
        lu.assertEquals(add(1,0),0)
        lu.assertEquals(add(0,5),0)
        lu.assertEquals(add(0,0),0)
    end

    function TestAdd:testAddError()
        lu.assertErrorMsgContains('Can only add positive or null numbers, received 2 and -3', add, 2, -3)
    end

    function TestAdd:testAdder()
        f = adder(3)
        lu.assertIsFunction( f )
        lu.assertEquals( f(2), 5 )
    end
-- end of table TestAdd

TestDiv = {}
    function TestDiv:testDivPositive()
        lu.assertEquals(div(4,2),2)
    end

    function TestDiv:testDivZero()
        lu.assertEquals(div(4,0),0)
        lu.assertEquals(div(0,5),0)
        lu.assertEquals(div(0,0),0)
    end

    function TestDiv:testDivError()
        lu.assertErrorMsgContains('Can only divide positive or null numbers, received 2 and -3', div, 2, -3)
    end
-- end of table TestDiv

--[[
--
--      Uncomment this section to see how failures are displayed
--
TestWithFailures = {}
    -- two failing tests

    function TestWithFailures:testFail1()
        lu.assertEquals( "toto", "titi")
    end

    function TestWithFailures:testFail2()
        local a=1
        local b='toto'
        local c = a + b -- oops, can not add string and numbers
        return c
    end
-- end of table TestWithFailures
]]


--[[
TestLogger = {}
    function TestLogger:setUp()
        -- define the fname to use for logging
        self.fname = 'mytmplog.log'
        -- make sure the file does not already exists
        os.remove(self.fname)
    end

    function TestLogger:testLoggerCreatesFile()
        initLog(self.fname)
        log('toto')
        f = io.open(self.fname, 'r')
        lu.assertNotNil( f )
        f:close()
    end

    function TestLogger:tearDown()
        self.fname = 'mytmplog.log'
        -- cleanup our log file after all tests
        os.remove(self.fname)
    end
-- end of table TestLogger

]]

os.exit(lu.LuaUnit.run())

Annex D: BSD License

This software is distributed under the BSD License.

Copyright (c) 2005-2018, Philippe Fremy <phil at freehackers dot org>

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.