unit tests (documentation request)

[pyramids]

I fail at writing unit tests for methods overwritten by @require. There are two problems I'm grappling with:

1. julia complains if I don't add the optional dependency to the package, possibly causing the next issue.
2. Whilst a test I want to write works in the REPL if I start with using my package and the optional dependency, it fails to replace the method in question when executed via ] test from the file test/runtests.jl.

Is there a chance that some documentation (or, better yet, a brief example) could be added to the documentation? Thanks alot!

[timholy]

A copy/pastable example would surely make this easier to address

[pyramids]

Thank you for the speedy reply. I made a minimum example project as follows.

Edited multiple times due to a bug. Fixed now.

src/Demo.jl:

module Demo
using Requires
#using DataFrames
#Base.show(io::IO, mime::MIME"text/html", df::DataFrame) = print(io, "success")
function __init__()
    @require DataFrames="a93c6f00-e57d-5684-b7b6-d8193f3e46c0" Base.show(io::IO, mime::MIME"text/html", df::DataFrames.DataFrame) = print(io, "success")
end # __init__
end # module

test/runtests.jl:

using Test
using DataFrames, Demo

@test begin
    io = IOBuffer()
    Base.show(io, "text/html", DataFrame())
    String(take!(io))
end == "success"

This works if I add DataFrames and then Requires as dependencies with ] add (and use the commented-out lines in src/Demo.jl instead of the @require line). In particular, ] test reports that the test passes.

Then I try removing the dependency on DataFrames and switch to the version of src/Demo.jl as shown above. Now the test fails saying I am missing the DataFrames package. Next I add it as an extra (test-only) dependency.

Project.toml then ends in

[deps]
Requires = "ae029012-a4dd-5104-9daa-d747884805df"
Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

[extras]
DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

[targets]
test = ["Test"]

But the error message about DataFrames being a missing package persists. It only works again (including the unit test) if I add it as a proper dependency. Doesn't it defeat Requires' purpose if I must add dependency packages into my project if I want to have unit tests?

[shipengcheng1230]

test = ["Test"]

Perhaps add DataFrames in addition in this line?

[timholy]

@shipengcheng1230 has the right answer; this is a package-management issue, not a Requires issue.