Fix handling of comments within import/using lists

src/runestone.jl

@@ -1039,7 +1039,7 @@ function format_importpath(ctx::Context, node::Node)
         node′ = replace_first_leaf(node, spacebar)
     else
         # No whitespace, insert
-        @assert kind(first_leaf(node)) in KSet"Identifier @" ||
+        @assert kind(first_leaf(node)) in KSet"Identifier @ Comment" ||
             JuliaSyntax.is_operator(first_leaf(node))
         kids′ = copy(verified_kids(node))
         pushfirst!(kids′, spacebar)

test/runtests.jl

@@ -848,6 +848,8 @@ end
                     "$(verb) A: $(a), $(b)"
                 @test format_string("$(verb) $(sp)A: $(sp)$(a)$(sp),\n$(b)") ==
                     "$(verb) A: $(a),\n    $(b)"
+                @test format_string("$(verb) $(sp)A: $(sp)$(a)$(sp),$(sp)# c\n$(b)") ==
+                    "$(verb) A: $(a), # c\n    $(b)"
             end
         end
     end