It looks like some opinionated script analysis warnings have been enabled for warnings W016 and W009, related to functions that implicitly return nil and return a non-value in other places, as well as unused variables
However, I have a case in which this warning is incorrect (this is a binary search to calculate a weighted random which always terminates):
Because I am using repeat until false, all code following the until false statement should be unreachable EXCEPT in the case that the loop breaks (which it doesn’t); however, script analysis still complains about this because it doesn’t understand that this portion of code is unreachable.
Contrived example of the issue:
local function alwaysReturnsTrue()
local x = 0
repeat
if x == 3 then
return true
end
x = x + 1
until false
end
Alternate form:
local function alwaysReturnsTrue()
local x = 0
while true do
if x == 3 then
return true
end
x = x + 1
end
end
In this case, the code after while true do . . . end is also unreachable, but a similar error is produced.
It seems like these warnings were turned on a bit prematurely… especially the one about implicit returns, it has to know a bit about type inference and control flow to be able to make an opinion like this. However, since Luau isn’t released yet (I have not enabled strict mode, nor do I have the beta feature enabled), it seems like this shouldn’t be enabled yet unless it can actually whether code like this is reachable.
In a language like TypeScript, it will check for the same thing, but it can tell that the block is unreachable, because the condition in the repeat/while block is a literal boolean type, so it doesn’t emit a similar error.
Yeah, I noticing those type of warning too in this new update. I thought I was the only one, I went from having no warning to 84 of them after the update. And all of them are related to not returning a value right after something like a if statement even though I have a return statement at the end of the same function.
function coreFunctions.ServiceDescendant(object) -- First Parent
local services = {
game:GetService('Workspace'),
game:GetService('Players'),
game:GetService('Lighting'),
game:GetService('ReplicatedFirst'),
game:GetService('ReplicatedStorage'),
--game:GetService('StarterGui'),
game:GetService('StarterPack'),
game:GetService('StarterPlayer'),
game:GetService('SoundService'),
game:GetService('HttpService'),
}
pcall(function()
for i,v in pairs(services) do
if object:IsDescendantOf(v) then return false end
end
end)
return true
end
^^Here is one out of the many warnings
This is a table that holds a function that looks at the descendants of specific services. When the For Loop ends it claims that this is a W016 warning, saying "Function can implicitly return no values even though there's an explicit return at line 40(referring to the if statement in the for loop); add explicit empty return to silence" The problem is that there no need for me to put a return at that part of the code because I already have a return at the end of it’s main function(coreFunctions.ServiceDescendant)
That warning seems correct to me. Your inner anonymous function (inside the pcall) is missing a return statement at the end. The return statement inside your pcall also only returns out of the inner function and doesn’t return false from coreFunctions.ServiceDescendant which looks to be a mistake.
