Behaviour for joining multiple S3Paths?

[nickrobinson251]

I've no idea what behaviour is expected or intended for joining together S3Paths

There is no test case for it. But here's what happens right now. We should maybe consider if this is what is wanted, then either add a test or fix it.

julia> abc = S3Path("s3://a/b/c/");  # trailing slash on `c`

julia> xyz = S3Path("s3://x/y/z");

julia> abc / xyz
p"s3://a/b/c/y/z/"  # trailing slash

julia> abc = S3Path("s3://a/b/c");  # no trailing slash on `c`

julia> abc / xyz  
p"s3://a/b/c/y/z"  # no trailing slash

julia> a = S3Path("s3://a");

julia> x = S3Path("s3://x/");

julia> a / x
p"s3://a"

[nickrobinson251]

Also, we special case joining strings:

julia> @which join(abc, "foo/bar")
join(prefix::S3Path, pieces::AbstractString...) in AWSS3 at /Users/nick/.julia/packages/AWSS3/UmYRI/src/s3path.jl:94

But for Paths in general, we fall back to the join defined on AbstractPaths in FilePathsBase.

julia> @which join(abc, p"foo/bar")
join(prefix::T, pieces::Union{AbstractString, AbstractPath}...) where T<:AbstractPath in FilePathsBase at /Users/nick/.julia/packages/FilePathsBase/Oyg1p/src/path.jl:230

This gives correct for WindowsPaths and PosixPaths

julia> abc / WindowsPath("foo/bar")
p"s3://a/b/c/foo/bar"

julia> abc / PosixPath("foo/bar")
p"s3://a/b/c/foo/bar"

But if we decide this behaviour in the opening post is not what we want for joining multiple S3Paths, we'll want to add a new join method.

[nickrobinson251]

i think joining multiple S3Paths is probably just nonsense.

If there's a public API to get the segments (is there?), then you can just explicitly do

julia> abc = S3Path("s3://a/b/c/");

julia> xyz = S3Path("s3://x/y/z");

julia> join(abc, xyz.segments...)
p"s3://a/b/c/y/z"

So i think join(::S3Path, ::S3Path) should be made a MethodError. Although if this isn't considered a bug-fix, then it is a breaking change, since it makes a non-error an error.

[nickrobinson251]

actually, afaict FilePathsBase does not test joining Paths to Paths at all https://github.com/rofinn/FilePathsBase.jl/blob/820903b2c8521f6a871ba7651763bcbce6754087/src/test.jl#L330