Fix test failures for Julia 1.8

[kdheepak]

Fixes #124

[kdheepak]

This is ready for review / ready to be merged.

[MichaelHatherly]

Just one comment/question on this inline. Thanks for sorting it out!

[kdheepak]

There's one printing that I currently don't like but don't know how to fix.

Given this type: Union{TypeVar(:T, Integer), TypeVar(:U, Float64)}, I want to construct this Union{T, U} where T<:Integer where U<:Float64. But I'm really struggling to figure out how to do that.

I thought this would do it but it just constructs the original type again:

julia> UnionAll(TypeVar(:U, Float64), UnionAll(TypeVar(:T, Integer), Union{TypeVar(:T, Integer), TypeVar(:U, Float64)}))
Union{T<:Integer, U<:Float64}

[kdheepak]

Previously, it was printing this:

k_7(x::Union{Nothing, T<:Integer}, y::Integer) -> Union{Nothing, T} where T<:Integer

Now, it'll print this:

k_7(x::Union{Nothing, T} where T<:Integer, y::Integer) -> Union{Nothing, T} where T<:Integer

Thanks to @pfitzseb for answering questions about this.

[kdheepak]

The only thing that remains now is the @test_broken tests. When I try to replicate the issue in a Julia script, the docs print correctly. This seems to be failing only in the test suite for some reason.

# test.jl
using DocStringExtensions
const DSE = DocStringExtensions
using Test
import Base.Docs: meta, @var, DocStr, parsedoc

module M end

function find_function_name_symbol(e::Expr)
    if e.head != :call
        return find_function_name_symbol(e.args[1])
    else
        return e.args[1]
    end
end

function get_doc_ext_signature(sym, typesig)
    doc = Docs.DocStr(Core.svec(), nothing, Dict())
    buf = IOBuffer()
    doc.data = Dict(
        :binding => Docs.Binding(M, sym),
        :typesig => eval(typesig),
        :module => M,
    )
    # @show doc.data
    DSE.format(DSE.TYPEDSIGNATURES, buf, doc)
    str = String(take!(buf))
    str = replace(str, "```julia" => "")
    str = replace(str, "```" => "")
    str = strip(str)
    return split(str, "\n")
end

function test()
    exprs = [
        :(
            k_7(x::T) where T = x
        )
    ]

    for expr in exprs

        println("# $(expr.args[1])")
        println()

        docs_sig = Base.Docs.signature(expr)
        Base.eval(M, expr)
        f = find_function_name_symbol(expr)

        docs_ext_sig = get_doc_ext_signature(f, docs_sig)
        @show first(docs_ext_sig)
        println()
    end
end

test()

julia --project test.jl                                                                                                  ─╯
# k_7(x::T) where T

first(docs_ext_sig) = "k_7(x) -> Any"

If I add @show doc.data:

doc.data = Dict{Symbol, Any}(:typesig => Tuple{T} where T, :module => Main.M, :binding => Main.M.k_7)

I get this output, which is what the test is using. So I'm very puzzled as to what is going on here.

[MichaelHatherly]

I'll try and investigate that one when I next get a chance, not sure what's happening with it either.

[kdheepak]

The three @test_broken tests were in there before I started this PR, but I'm pretty sure it's just something silly I'm missing. It'd be nice if we sorted it out in this PR, but also it is not necessary and this can be merged.

[kdheepak]

I'm not sure exactly why this happens, but when I comment the other tests out or if I move the test to the beginning of the testset, the broken tests pass. I put some prints in the code to see where the difference was and it happens at this line:

DocStringExtensions.jl/src/abbreviations.jl

Line 375 in 8cac180

local groups = methodgroups(func, typesig, modname)

When the test is at the end of the testset, this function returns an empty Vector. When it is at the beginning, it returns the expected Vector of method groups. In fact, anywhere before the test for k_3 and it works fine. After k_3 though, it fails. I renamed it to k_0 and moved it to a different location.

[MichaelHatherly]

Thanks for tracking that down further. Very weird behavior, if things are all working now and you're happy with the implementation then we can merge as is.

[kdheepak]

Yup! I am happy with it!

[MichaelHatherly]

Thanks again for sorting that one out!

[kdheepak]

Thanks for pinging me! Feel free to do so again if something else comes up with this.