Spilled a tea on my MacBook keyboard

Hi,

I’ve spilled a tea (no sugar, no milk) on my Mac keyboard. It was 1/3 of 0,4l glass, so not that much. Also, the tea is not that acidic, is it? I immeditally plugged everything off and switched the device off. Then I left it upside down for 24hrs to dry it out and to let the water eventually come out. After that, I took the Mac to the closest Apple store. They did run a diagnosis test and no issue was found, everything just works fine.. However, I was advice to make a repair of a top case with keybord and trackpad - the cost is £300. I have a deadline for my Masters dissertation in two weeks and need to use the laptop.

Could anyone please tell me if I can use it when the diagnostic test has not found any issue? Is there any chance that I’m just a lucky guy and the laptop passed with no damage?