lua-language-server
lua-language-server copied to clipboard
Invalid type diagnostic doesn't show when passing value from array directly to a function
How are you using the lua-language-server?
Other
Which OS are you using?
Linux
What is the issue affecting?
Type Checking, Diagnostics/Syntax Checking
Expected Behaviour
When using a value from an array as a parameter I expect type checking to work.
Actual Behaviour
Type checking only works when I assign the value from the array to a temporary variable, not when passing it to a function directly.
Reproduction steps
This doesn't show a warning:
---@param num integer
function receive(num)
end
---@type (integer?)[]
local values = {}
receive(values[1])
This works:
local value = values[1]
receive(value) -- Cannot assign `integer?` to parameter `integer`.
Additional Notes
No response
Log File
No response
if values[1] then
receive(values[1]) --> dose not support narrow `integer?` to `integer` in this case
end
Since the expression cannot be narrowed at present, I can only ignore nil type to prevent false warning.
Is the following an instance of the same issue or a different one? It would be really useful to get warnings about nil values when assigning an array (e.g. when using variables for array elements and mistyped a variable name: local x = { a.first, a.seeecond, a.third })
---@type string[]
local x = { 'a', nil, 'b' } -- no assign-type-mismatch
local y = x[2] -- y is string, but can actually be nil