ContextActionService BindInput Method Firing When Input Not Pressed

[Marked4Destruction (GuyMcFly)]

When binding actions to Left Shift and C using ContextActionService, I get unwanted function fires when pressing these keys in this sequence - hold Left Shift, hold C, release Left Shift. It will produce an extra and unwanted “Begin” InputState from the C key, even though it hasn’t been released. Here’s the script that causes the issue and the resulting output:

local contextActionService = game:GetService("ContextActionService")

local function crouch (actionName:string, inputState:Enum.UserInputState, inputObject:InputObject)
	print("Crouch "..tostring(inputState))
end

local function sprint (actionName, inputState, inputObject)
	print("Sprint "..tostring(inputState))
end

contextActionService:BindAction("Crouch", crouch, false, Enum.KeyCode.C)
contextActionService:BindAction("Sprint", sprint, false, Enum.KeyCode.LeftShift)

Expected behavior

BindFunction should only fire its specified function when the InputState of an input changes. There should be a “Begin” InputState only when a button is pressed down, and an “End” InputState only when the button is released.

[NoUniqueAddress]

Thanks for the report! We’ll look into it.

[Marked4Destruction (GuyMcFly)]

Some newly discovered information regarding this topic (you can go to this forum post to see the reply, but I’ll summarize here what was said):

ContextActionService Bug

It looks like the reason you get an extra trigger after releasing LeftShift is because this key is seen as a “modifier key”. I’m not certain if this is the intended behavior or not, but you can see the change with this code: local ContextActionService = game:GetService("ContextActionService") local function crouch(action: string, state: Enum.UserInputState, io: InputObject) print("Crouch", state, io:IsModifierKeyDown(Enum.ModifierKey.Shift)) end local function sprint(action: string, state: E…

Summary:
This issue seems to be related to Left Shift being a “modifier key” (see InputObject:IsModifierKeyDown()). I’m not sure if this extra InputState is intended, but personally, I would rather it didn’t happen. Using the IsModifierKeyDown method does not solve the problem, because I still want to perform the action bound to C whether a modifier key is down or not. Hopefully this information helps.

[Paragraph3232]

@Marked4Destruction , we rolled out a change that should improve handling of the modifier keys. Can you please check if you see the expected event sequence?