--
-- ASSERT.LUA Copyright (c) 2006-07, <akauppi@gmail.com>
--
-- Converting the Lua 'assert' function into a namespace table (without
-- breaking compatibility with the basic 'assert()' calling).
--
-- This module allows shorthand use s.a. 'assert.table()' for asserting
-- variable types, and is also being used by Lua-super constraints system
-- for testing function parameter & return types.
--
-- All in all, a worthy module and could be part of Lua future versions.
--
-- Note: the 'assert' table is available for your own assertions, too. Just add
-- more functions s.a. 'assert.myobj()' to check for custom invariants.
-- They will then be available for the constraints check, too.
--
-- Author: <akauppi@gmail.com>
--
--[[
/******************************************************************************
* Lua 5.1.1 support and extension functions (assert.lua)
*
* Copyright (C) 2006-07, Asko Kauppi.
*
* NOTE: This license concerns only the particular source file; not necessarily
* the project with which it has been delivered (the project may have a more
* restrictive license, s.a. [L]GPL).
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
******************************************************************************/
]]--
local m= { _info= { MODULE= "Assert.* functions for constraints, and unit testing",
AUTHOR= "akauppi@gmail.com",
VERSION= 20070603, -- last change (yyyymmdd)
LICENSE= "MIT/X11" } }
-- Global changes:
-- 'assert' redefined, in a backwards compatible way
--
-- Module functions:
-- none
assert( type(assert) == "function" ) -- system assert function
-----
-- Integer range: INT_MIN..INT_MAX
--
local function try_maxint( n )
return (n > n-1) and n-1 -- false when outside the integer range
end
local INT_MAX=
try_maxint( 2^64 ) or
try_maxint( 2^32 ) or
try_maxint( 2^24 ) or -- float (24-bit mantissa)
assert( false )
local INT_MIN= -(INT_MAX+1)
---=== assert.*() ===---
local at_msg= "type assertion error" -- TBD: better messages, about that exact situation
local av_msg= "value assertion error"
-- void= _assert( val [, msg_str [, lev_uint]] )
--
local function _assert( cond, msg, lev )
-- original 'assert' provides no level override, so we use 'error'.
--
if not cond then
error( msg or "assertion failed!", (lev or 1)+1 )
end
end
-- Note: following code uses the _new_ 'assert()' by purpose, since it provides
-- a level override (original doesn't)
--
local function assert_v( v0 )
return function(v,msg)
_assert( v == v0, msg or av_msg, 2 )
return v
end
end
local function assert_t( str )
return function(v,msg)
_assert( type(v) == str, msg or at_msg, 2 )
return v
end
end
local function assert_t2( str )
return function(v,subtype,msg)
local t,st= type(v)
_assert( t==str and ((not subtype) or (st==subtype)),
msg or at_msg, 2 )
return v
end
end
assert=
{
__call= function(_,v,msg) -- plain 'assert()' (compatibility)
if v then return v end
_assert( v, msg, 2 )
end,
-- Hopefully, Lua will allow use of 'nil', 'function' and other reserved words as table
-- shortcuts in the future (5.1.1 does not).
--
["nil"]= assert_v( nil ),
boolean= assert_t "boolean",
table= assert_t2 "table",
["function"]= assert_t "function",
userdata= assert_t2 "userdata",
string= function( v, msg )
local s= tostring(v)
_assert( s, msg or at_msg, 2 )
return v
end,
char= function( v, msg )
-- 'char' is _not_ doing int->string conversion
_assert( type(v)=="string" and v:len()==1, msg or at_msg, 2 )
return v
end,
number= function( v, msg )
_assert( tonumber(v), msg or at_msg, 2 )
return v
end,
int= function( v, msg )
local n= tonumber(v)
_assert( n and (n >= INT_MIN) and (n <= INT_MAX) and math.floor(n) == n,
msg or at_msg, 2 )
return v
end,
uint= function( v, msg )
local n= tonumber(v)
-- unsigned integer upper range is the same as integers' (there's no
-- real unsigned within the Lua)
_assert( n and (n >= 0) and (n <= INT_MAX) and math.floor(n) == n,
msg or at_msg, 2 )
return v
end,
['true']= assert_v( true ),
['false']= assert_v( false ),
string_or_table= function( v, msg )
assert( tostring(v) or type(v)=="table", msg or at_msg, 2 )
return v
end,
number_or_string= function( v, msg )
assert( tonumber(v) or type(v)=="table", msg or at_msg, 2 )
return v
end,
any= function( v, msg )
assert( v ~= nil, msg or av_msg, 2 )
return v
end,
-- Range assertion, with extra parameters per instance
--
-- Note: values may be of _any_ type that can do >=, <= comparisons.
--
range= function( lo, hi )
_assert( lo and hi and lo <= hi, "Bad limits", 2 )
-- make sure the limits make sense (just once)
return function(v,msg,lev)
if ( (lo and v<lo) or (hi and v>hi) ) then
msg= msg or "not in range: ("..(lo or "")..","..(hi or "")..")"
_assert( false, msg, 2 )
end
return v
end
end,
-- Table contents assertion
-- - no unknown (non-numeric) keys are allowed
-- - numeric keys are ignored
--
-- Constraints patch should point to this, when using the ":{ ... }" constraint.
--
["{}"]= function( tbl )
-- check all keys in 't' (including numeric, if any) that they do exist,
-- and carry the right type
--
local function subf1(v,t,msg,lev)
_assert(lev)
for k,f in pairs(t) do
-- 'f' is an assert function, or subtable
local ft= type(f)
if ft=="function" then
f( v[k], msg, lev+1 )
elseif ft=="table" then
_assert( type(v[k])=="table", msg or "no subtable "..tostring(k), lev+1 )
subf1( v[k], f, msg, lev+1 )
else
error( "Bad constraints table for '"..tostring(k).."'! (not a function)", lev+1 )
end
end
end
-- check there are no other (non-numeric) keys in 'v'
local function subf2(v,t,msg,lev)
_assert(lev)
for k,vv in pairs(v) do
if type(k)=="number" then
-- skip them
elseif not t[k] then
_assert( false, msg or "extra field: '"..tostring(k).."'", lev+1 )
elseif type(vv)=="table" then
subf2( vv, t[k], msg, lev+1 )
end
end
end
_assert( type(tbl)=="table", "Wrong parameter to assert['{}']" )
return function( v, msg, lev )
lev= (lev or 1)+1
_assert( type(v)=="table" ,msg, lev )
subf1( v, tbl, msg, lev )
subf2( v, tbl, msg, lev )
return v
end
end,
-- ...
}
setmetatable( assert, assert )
assert.void= assert["nil"]
-----
-- void= assert.fails( function [,err_msg_str] )
--
-- Special assert function, to make sure the call within it fails, and gives a
-- specific error message (to be used in unit testing).
--
function assert.fails( func_block, err_msg )
--
local st,err= pcall( func_block )
if st then
_assert( false, "Block expected to fail, but didn't.", 2 )
elseif err_msg and err ~= err_msg then
_assert( false, "Failed with wrong error message: \n"..
"'"..err.."'\nexpected: '"..err_msg.."'", 2 )
end
end
-----
-- void= assert.failsnot( function [,err_msg_str] )
--
-- Similar to 'assert.fails' but expects the code to survive.
--
function assert.failsnot( func_block, err_msg )
--
local st,err= pcall( func_block )
if not st then
_assert( false, "Block expected NOT to fail, but did."..
(err and "\n\tError: '"..err.."'" or ""), 2 )
end
end
-----
-- void= assert.nilerr( function [,err_msg_str] )
--
-- Expects the function to return with 'nil,err' failure code, with
-- optionally error string matching. Similar to --> 'assert.fails()'
--
function assert.nilerr( func_block, err_msg )
--
local v,err= func_block()
_assert( v==nil, "Expected to return nil, but didn't: "..tostring(v), 2 )
if err_msg and err ~= err_msg then
_assert( false, "Failed with wrong error message: \n"..
"'"..err.."'\nexpected: '"..err_msg.."'", 2 )
end
end
-- Sanity check
--
assert( true )
assert.fails( function() assert( false ) end )
assert.fails( function() assert( nil ) end )
return m -- just info