Occasionally, applying hlint suggestions doesn't work as expected

Since the latest beta (?) applying hlint suggestions doesn’t always work. There are some cases where it does work, and others where the suggestion is inserted without overriding existing code. Here’s a sample:

sample :: [Int] -> (Int -> Int) -> [String]
sample xs f = (show . f) <$> xs

IntelliJ offers me a quick fix saying:

Reudundant bracket, change to show . f <$> xs

when I apply the fix, I end up with the following:

sample xs f = show . f <$> xs <$> xs

So, it doesn’t override <$> xs but inserts it (similar to when I press Enter instead of Tab for completion).

My guess is that it is related to when there are a function composition operator and redundant brackets involved, but I’m not sure about that.

I’m on plugin version 1.0.0-beta78, IntellIJ IDEA 2020.2.1 RC (Ultimate Edition) Build #IU-202.6948.36 (I faced the issue with 2020.2 as well)

[L7R7]

I totally missed the notifications on this issue, sorry for letting you wait! I just downloaded beta85 and tried it. I can tell that it definitely got better. The fixes for my first examples work now (the sample function ones). However, the last one is still a bit weird. For this one:

blabla = (\header -> (fst header) == "privateToken")

I get three suggestions (two redundant brackets and one redundant lambda). The fixes for brackets work, but when I apply the fix for the redundant lambda I get:

blheaderblheader header = (fst heheaderder) == "privheaderteToken"

Interestingly, the suggestion in the popup is weird already:

I get the same behavior even when I apply the fixes for the brackets first

[rikvdkleij]

Investigated this issue and to solve this properly I have to change the integration with HLint. Will take some effort but it’s necessary.