fix int overflow

Author: ligurio

luzer/tests/test_unit.lua

@@ -16,7 +16,18 @@ local err
 local fdp
 local res
 
-local MAX_INT = 2^51
+-- By default `lua_Integer` is long long, (usually a 64-bit
+-- two-complement integer), but that can be changed to long or
+-- int (usually a 32-bit two-complement integer), see LUA_INT_TYPE
+-- in <luaconf.h>. Lua 5.3+ has two functions:
+-- `math.maxinteger` and `math.mininteger` that returns an integer
+-- with the maximum value for an integer and an integer with the
+-- minimum value for an integer, see [1].
+--
+-- 1. https://www.lua.org/manual/5.3/manual.html#lua_Integer
+local MAX_INT64 = 0x7fffffffffffffff
+local MAX_INT = math.maxinteger or MAX_INT64
+local MIN_INT = math.mininteger or -MAX_INT64
 
 -- luzer.FuzzedDataProvider()
 assert(type(luzer.FuzzedDataProvider) == "function")
@@ -138,7 +149,7 @@ assert(ok == false)
 assert(err ~= nil)
 
 -- luzer.FuzzedDataProvider.consume_integer()
-fdp = luzer.FuzzedDataProvider("AB")
+fdp = luzer.FuzzedDataProvider(string.rep("ABC", 1000))
 assert(type(fdp.consume_integer) == "function")
 
 res = fdp:consume_integer(10, 20)
@@ -150,7 +161,15 @@ ok, err = pcall(fdp.consume_integer)
 assert(ok == false)
 assert(err ~= nil)
 
-local i = fdp:consume_integer(1, MAX_INT)
+local max_int = fdp:consume_integer(MAX_INT, MAX_INT)
+assert(type(max_int) == "number")
+assert(max_int == MAX_INT)
+
+local min_int = fdp:consume_integer(MIN_INT, MIN_INT)
+assert(type(min_int) == "number")
+assert(min_int == MIN_INT)
+
+local i = fdp:consume_integer(MIN_INT, MAX_INT)
 assert(type(i) == "number")
 
 -- luzer.FuzzedDataProvider.consume_integers()