improve a msg

Author: jw3126

Project.toml

@@ -1,7 +1,7 @@
 name = "WhyNotEqual"
 uuid = "e6125b7d-2298-432f-af45-a1235af9403e"
 authors = ["Jan Weidner <jw3126@gmail.com> and contributors"]
-version = "0.2.0"
+version = "0.2.1"
 
 [deps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"

src/WhyNotEqual.jl

@@ -60,6 +60,7 @@ function Base.show(io::IO, res::ChildrenTraitMismatch)
     println(io, "These have different child traits.")
     t1 = ChildrenT(res.obj1)
     t2 = ChildrenT(res.obj2)
+    println(io, "lens: ", repr(res.lens))
     println(io, "ChildrenT(obj1) = ", t1)
     println(io, "ChildrenT(obj2) = ", t2)
 end

test/runtests.jl

@@ -110,6 +110,11 @@ end
 
 @test whynot(==, AB(1,2), AB(1,[2])) isa WN.ChildrenTraitMismatch
 @test whynot(==, AB(1,2), AB(1,[2])).lens === (@optic _.b)
+res = whynot(==, AB(1,2), AB(1,[2]))
+s = sprint(show,res)
+@test occursin("lens", s)
+@test occursin("@optic", s)
+@test occursin("_.b", s)
 
 @testset "readme" begin
     expected = (