Doctests for modules are troublesome (premature end of input)

[timholy]

In #35094 I initially used jldoctest for the demonstration, but I got several errors that, in the end, I gave up trying to fix. I suspect this is mostly because it created a new module. Suspiciously, the modules chapter of the manual is entirely free of doctests.

The fundamental error is

 ```jldoctest
│ julia> module Hinter
│ 
│        only_int(x::Int)      = 1
│        any_number(x::Number) = 2
│ 
│        function __init__()
│            register_error_hint(MethodError) do io, exc, argtypes, kwargs
│                if exc.f == only_int
│                     print(io, "\nDid you mean to call ")
│                     printstyled(io, "`any_number`?", color=:light_magenta)
│                end
│            end
│        end
│ 
│        end
│ Main.Hinter
│ 
│ julia> Hinter.only_int(1.0)
│ ERROR: MethodError: no method matching only_int(::Float64)
│ Did you mean to call `any_number`?
│ Closest candidates are:
│ [...]
│ ```
│ 
│ Subexpression:
│ 
│ module Hinter
│ 
│ Evaluated output:
│ 
│ ERROR: syntax: incomplete: premature end of input
│ Stacktrace:
│  [1] top-level scope at none:180
│ 
│ Expected output:
│ 
│ 
│        only_int(x::Int)      = 1
│        any_number(x::Number) = 2
│ 
│        function __init__()
│            register_error_hint(MethodError) do io, exc, argtypes, kwargs
│                if exc.f == only_int
│                     print(io, "\nDid you mean to call ")
│                     printstyled(io, "`any_number`?", color=:light_magenta)
│                end
│            end
│        end
│ 
│        end
│ Main.Hinter
│ 
│   diff =
│    Warning: Diff output requires color.
│    
│           only_int(x::Int)      = 1
│           any_number(x::Number) = 2
│    
│           function __init__()
│               register_error_hint(MethodError) do io, exc, argtypes, kwargs
│                   if exc.f == only_int
│                        print(io, "\nDid you mean to call ")
│                        printstyled(io, "`any_number`?", color=:light_magenta)
│                   end
│               end
│           end
│    
│           end
│    Main.HinterERROR: syntax: incomplete: premature end of input
│    Stacktrace:
│     [1] top-level scope at none:180
└ @ Documenter.DocTests ~/src/julia-master/doc/deps/packages/Documenter/HmOsT/src/DocTests.jl:369
┌ Error: doctest failure in errorshow.jl

[fredrikekre]

This is probably due to Documenters heuristics on how to split input from output.

[fredrikekre]

Probably works if you write it with not empty lines, i.e.

julia> module Hinter
       only_int(x::Int)      = 1
       any_number(x::Number) = 2
       function __init__()
           register_error_hint(MethodError) do io, exc, argtypes, kwargs
               if exc.f == only_int
                    print(io, "\nDid you mean to call ")
                    printstyled(io, "`any_number`?", color=:light_magenta)
               end
           end
       end
       end

[tkf]

xref JuliaDocs/Documenter.jl#963