Wraper functions for 8.0.1 spell/aura changes

[Edik]

I have set of functions to wrap changes without no need to modify old code for transcending period in addon development. It allows still use code in 7.3 and 8.x. Just replace P. with your add-on name and then inlude at start of your code:

local GetSpellInfo = P.GetSpellInfo; assert(GetSpellInfo ~= nil,'GetSpellInfo')

If you want to use GetSpellInfo without need to worry about client version. Here are wrappers

-- LINT frinedly declaration
local GetBuildInfo = _G.GetBuildInfo; assert(GetBuildInfo ~= nil,'GetBuildInfo')
-- transience 7.x na 8.x
local _, _, _, tocVersion = GetBuildInfo() -- resolve version
-- wrappers
function P.UnitChannelInfo(unit) -- 7.x to 8.x transience 2nd return value removed
  if tocVersion < 80000 then return _G.UnitChannelInfo(unit) end
  local retTable = {_G.UnitChannelInfo(unit)}
  if retTable[1] then table.insert(retTable,2,'') end
  return unpack(retTable)
end
function P.UnitCastingInfo(...) -- 7.x to 8.x transience 2nd return value removed
  if tocVersion < 80000 then return _G.UnitCastingInfo(...) end
  local retTable = {_G.UnitCastingInfo(...)}
  if retTable[1] then table.insert(retTable,2,'') end
  return unpack(retTable)
end
function P.GetSpellInfo(...) -- 7.x to 8.x transience 2nd return value replaced with nil
  if tocVersion < 80000 then return _G.GetSpellInfo(...) end
  local retTable = {_G.GetSpellInfo(...)}
  if retTable[1] then retTable[2] = '' end
  return unpack(retTable)
end
function P.GetMacroSpell(...) -- 7.x to 8.x transience 1st and 2nd return value removed
  if (tocVersion < 80000) then return _G.GetMacroSpell(...) end
  local retTable = {_G.GetMacroSpell(...)}
  if retTable[1] then
    local name = _G.GetSpellInfo(retTable[1])
    if name then 
      table.insert(retTable,1,'')
      table.insert(retTable,1,name)
    end
  end
  return unpack(retTable)
end
function P.GetPetActionInfo(...) -- 7.x to 8.x transience 2nd return value removed
  if (tocVersion < 80000) then return _G.GetPetActionInfo(...) end
  local retTable = {_G.GetPetActionInfo(...)}
  if retTable[1] then table.insert(retTable,2,'') end
  return unpack(retTable)
end
function P.GetPossessInfo(...) -- 7.x to 8.x transience 2nd return value changed from spell name to spell ID.
  if (tocVersion < 80000) then return _G.GetPossessInfo(...) end
  local retTable = {_G.GetPossessInfo(...)}
  if retTable[2] then
    local name = _G.GetSpellInfo(retTable[2])
    retTable[2] = name
  end
  return unpack(retTable)
end
function P.GetItemSpell(...) -- 7.x to 8.x transience 2nd return value removed
  if (tocVersion < 80000) then return _G.GetItemSpell(...) end
  local retTable = {_G.GetItemSpell(...)}
  if retTable[1] then table.insert(retTable,2,'') end
  return unpack(retTable)
end
function P.GetSpellLink(...) -- 7.x to 8.x transience 2nd return value removed
  if (tocVersion < 80000) then return _G.GetSpellLink(...) end
  local retTable = {_G.GetSpellLink(...)}
  if retTable[1] then table.insert(retTable,2,_G.GetSpellTradeSkillLink(...)) end
  return unpack(retTable)
end
local UnitAuraCache = {} -- cached values are updated ten times per second and stored by unit+filter
function P.UnitAura(unit, ...) -- 7.x to 8.x transience 2nd return value removed and only spellID argument is supported
  if tocVersion < 80000 then return _G.UnitAura(unit, ...) end
  local retTable
  local index = select(1,...)
  if type(index) == 'number' then -- now only spellID is accepted
    retTable = {_G.UnitAura(unit, ...)}
    if retTable[1] then table.insert(retTable,2,'') end
  elseif type(index) == 'string' then -- lokup by spellName must be done on own by fetching all auras and then looking up by name
    local index, _, filter = select(1,...)
    local key = string.lower(filter or 'default')
    index = string.lower(index) -- lookup by spell name
    unit = string.lower(unit)
    local cache = UnitAuraCache[unit] -- fetch unit aura cache
    if cache and cache[key] and cache[key]['stamp'] == ("%.1f"):format(GetTime()) then -- cached values updated 10 times per second
      if cache[key][index] then retTable = cache[key][index] else retTable = {} end
    else -- fetch new cached values
      if not UnitAuraCache[unit] then UnitAuraCache[unit] = {} end
      if not UnitAuraCache[unit][key] then UnitAuraCache[unit][key] = {} else table.wipe(UnitAuraCache[unit][key]) end
      cache = UnitAuraCache[unit][key]
      local n = 1
      local name
      repeat
        retTable = {_G.UnitAura(unit, n, filter)}
        name = retTable[1]
        if name then
          table.insert(retTable,2,'')
          cache[string.lower(name)] = table.copy(retTable)
        end
        n = n + 1
      until not name;
      cache['stamp'] = ("%.1f"):format(GetTime())
      if cache[index] then
        retTable = cache[index]
      else
        retTable = {nil}
      end
    end
  end
  return unpack(retTable)
end
local UnitBuffCache = {} -- cached values are updated ten times per second and stored by unit+filter
function P.UnitBuff(unit, ...) -- 7.x to 8.x transience 2nd return value removed and only spellID argument is supported
  if tocVersion < 80000 then return _G.UnitBuff(unit, ...) end
  local retTable
  local index = select(1,...)
  if type(index) == 'number' then -- now only spellID is accepted
    retTable = {_G.UnitBuff(unit, ...)}
    if retTable[1] then table.insert(retTable,2,'') end
  elseif type(index) == 'string' then -- lokup by spellName must be done on own by fetching all auras and then looking up by name
    local index, _, filter = select(1,...)
    local key = string.lower(filter or 'default')
    index = string.lower(index) -- lookup by spell name
    unit = string.lower(unit)
    local cache = UnitBuffCache[unit] -- fetch unit aura cache
    if cache and cache[key] and cache[key]['stamp'] == ("%.1f"):format(GetTime()) then -- cached values updated 10 times per second
      if cache[key][index] then retTable = cache[key][index] else retTable = {} end
    else -- fetch new cached values
      if not UnitBuffCache[unit] then UnitBuffCache[unit] = {} end
      if not UnitBuffCache[unit][key] then UnitBuffCache[unit][key] = {} else table.wipe(UnitBuffCache[unit][key]) end
      cache = UnitBuffCache[unit][key]
      local n = 1
      local name
      repeat
        retTable = {_G.UnitBuff(unit, n, filter)}
        name = retTable[1]
        if name then
          table.insert(retTable,2,'')
          cache[string.lower(name)] = table.copy(retTable)
        end
        n = n + 1
      until not name;
      cache['stamp'] = ("%.1f"):format(GetTime())
      if cache[index] then
        retTable = cache[index]
      else
        retTable = {nil}
      end
    end
  end
  return unpack(retTable)
end
local UnitDebuffCache = {} -- cached values are updated ten times per second and stored by unit+filter
function P.UnitDebuff(unit, ...) -- 7.x to 8.x transience 2nd return value removed and only spellID argument is supported
  if tocVersion < 80000 then return _G.UnitDebuff(unit, ...) end
  local retTable
  local index = select(1,...)
  if type(index) == 'number' then -- now only spellID is accepted
    retTable = {_G.UnitDebuff(unit, ...)}
    if retTable[1] then table.insert(retTable,2,'') end
  elseif type(index) == 'string' then -- lokup by spellName must be done on own by fetching all auras and then looking up by name
    local index, _, filter = select(1,...)
    local key = string.lower(filter or 'default')
    index = string.lower(index) -- lookup by spell name
    unit = string.lower(unit)
    local cache = UnitDebuffCache[unit] -- fetch unit aura cache
    if cache and cache[key] and cache[key]['stamp'] == ("%.1f"):format(GetTime()) then -- cached values updated 10 times per second
      if cache[key][index] then retTable = cache[key][index] else retTable = {} end
    else -- fetch new cached values
      if not UnitDebuffCache[unit] then UnitDebuffCache[unit] = {} end
      if not UnitDebuffCache[unit][key] then UnitDebuffCache[unit][key] = {} else table.wipe(UnitDebuffCache[unit][key]) end
      cache = UnitDebuffCache[unit][key]
      local n = 1
      local name
      repeat
        retTable = {_G.UnitDebuff(unit, n, filter)}
        name = retTable[1]
        if name then
          table.insert(retTable,2,'')
          cache[string.lower(name)] = table.copy(retTable)
        end
        n = n + 1
      until not name;
      cache['stamp'] = ("%.1f"):format(GetTime())
      if cache[index] then
        retTable = cache[index]
      else
        retTable = {nil}
      end
    end
  end
  return unpack(retTable)
end
function P.GetPlayerMapPosition(...) -- 7.x to 8.x transinece function removed, this just simulate old function buth with different scale
  if tocVersion < 80000 then return _G.GetPlayerMapPosition(...) end
  local x, y = _G.UnitPosition(...)
  if type(x) == 'number' and type(y) == 'number' then
    x = x / 1000.0
    y = y / 1000.0
  end
  return x, y
end