errors and warnings / stdlib / E8030

E8030 error

Deferred-call decorator on a function that returns values

area: stdlib (x8xxx)
fails the build: yes

@throttle, @debounce and @nextFrame from wowlua:timer, and @outOfCombat from wowlua:combat, may run the function later than it was called, or merge several calls into one. The caller never gets a result back, so the decorated function must not return values.

Remove the return values. If the caller needs a result, pass it on another way, such as a field the function sets or a callback it calls.

Example

× failswowlua

import throttle from "wowlua:timer" @throttle(0.5)local function refresh(): boolean    print("refresh")    return trueendrefresh()

✓ compileswowlua

import throttle from "wowlua:timer" @throttle(0.5)local function refresh()    print("refresh")endrefresh()

The compiler reports it like this:

error[E8030]: `@throttle` may run the function later, so it must not return values
  ┌─ src/main.wowlua:3:1
  │
3 │ @throttle(0.5)
  │ ^^^^^^^^^^^^^^ defers the call

Offline

terminal

$ wowlua explain E8030
E8030 (error): Deferred-call decorator on a function that returns values

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