We can use would to express annoyance or irritation at things that are happening now. There is usually a sense that this is typical, or not very surprising.
You would say that! ( it's typical of you, and it's annoying ).
Wouldn't you just know it! ( I knew that would happen — and it's annoying ).
--Page 78 (Macmillan - Inside Out English Grammar in Context Advanced)
However:
Stressed will can be used to criticise people's typical behaviour.
She WILL fall in love with the wrong people.
Well, if you WILL keep telling people what you think of them ...
Stressed would can also be used to criticise a single past action - the meaning is 'that's typical of you'.
You WOULD tell Mary about the party - I didn't want to invite her.
-- 633.7, Michael Swan's, Practical English Usage.
I would think these two versions don't agree with each other. Which one is more precise and correct?
If PEU is right, the example in Macmillan would be "You WILL say that!"
Besides, is "Wouldn't you just know it!" a rhetorical question? How to parse it?