Generic type for test callback functions

lib/types.luau

@@ -15,4 +15,6 @@ export type opts = {
 
 export type model = {Instance}
 
+export type callbackFunction = (file: string, opts: opts) -> string | boolean
+
 return types

tests/tests.luau

@@ -5,7 +5,7 @@ local compression = require("../lib/compression")
 local types = require("../lib/types")
 
 
-function testFolder(callback: (file: string, opts: types.opts) -> string | boolean, opts: types.opts, folderPath: string): {boolean}
+function testFolder(callback: types.callbackFunction, opts: types.opts, folderPath: string): {boolean}
     local results = {}
     local folder = fs.readDir(folderPath)
     for _, file in pairs(folder) do