Warn and Fail constraints in instance context of superclasses are ignored when deriving newtype instances #3964
Description
Description
What the issue title says.
To Reproduce
The following example doesn’t yield any warning:
module Example where
import Prim.TypeError (class Warn, Text)
class Deprecated
instance deprecated :: Warn (Text "deprecated") => Deprecated
class Deprecated <= C (a :: Type)
newtype N a = N a
derive newtype instance c :: C a => C (N a)but a regular instance declaration does:
instance c :: C a => C (N a)Warning found:
in module Example
at Example.purs:12:1 - 12:29 (line 12, column 1 - line 12, column 29)
A custom warning occurred while solving type class constraints:
deprecated
in value declaration c
See https://github.com/purescript/documentation/blob/master/errors/UserDefinedWarning.md for more information,
or to contribute content related to this warning.
Expected behavior
Deriving newtype instances should yield the same warnings and failures than regular instances declarations.
PureScript version
0.14.0-rc3