If user does e.g. Pkg.add("Foo.jl"), instruct them to do Pkg.add("Foo") instead

[DilumAluthge]

In documentation and other prose, we often refer to Julia packages as "PackageName.jl". So I think it is understandable that a user would try to do Pkg.add("PackageName.jl").

This PR prints an instructive message if a user tries to do that.

[fredrikekre]

I think this should be part of the error message instead, e.g.

julia> Pkg.add("Example.jl")
ERROR: `Example.jl` is not a valid package name, perhaps you meant `Example`?

instead of the current

julia> Pkg.add("Example.jl")
ERROR: `Example.jl` is not a valid package name

[DilumAluthge]

Done.

[DilumAluthge]

I think the CI failures are unrelated: (click to expand)

411precompile: Error During Test at /home/travis/build/JuliaLang/Pkg.jl/test/new.jl:1819
412  Got exception outside of a @test
413  MethodError: no method matching Base.TOMLCache()
414  Closest candidates are:
415    Base.TOMLCache(::Base.TOML.Parser, ::Dict{String, Base.CachedTOMLDict}) at loading.jl:215
416    Base.TOMLCache(::Any, ::Any) at loading.jl:215
417  Stacktrace:
418    [1] precompile(ctx::Pkg.Types.Context; internal_call::Bool)
419      @ Pkg.API ~/build/JuliaLang/Pkg.jl/src/API.jl:968
420    [2] precompile(; internal_call::Bool)
421      @ Pkg.API ~/build/JuliaLang/Pkg.jl/src/API.jl:916
422    [3] precompile()
423      @ Pkg.API ~/build/JuliaLang/Pkg.jl/src/API.jl:916
424    [4] (::Main.PkgTests.NewTests.var"#544#546")()
425      @ Main.PkgTests.NewTests ~/build/JuliaLang/Pkg.jl/test/new.jl:1829
426    [5] (::Main.PkgTests.Utils.var"#4#7"{Bool, Main.PkgTests.NewTests.var"#544#546"})()
427      @ Main.PkgTests.Utils ~/build/JuliaLang/Pkg.jl/test/utils.jl:52
428    [6] withenv(::Main.PkgTests.Utils.var"#4#7"{Bool, Main.PkgTests.NewTests.var"#544#546"}, ::Pair{String, Nothing}, ::Vararg{Pair{String, Nothing}, N} where N)
429      @ Base ./env.jl:161
430    [7] isolate(fn::Main.PkgTests.NewTests.var"#544#546"; loaded_depot::Bool)
431      @ Main.PkgTests.Utils ~/build/JuliaLang/Pkg.jl/test/utils.jl:43
432    [8] isolate(fn::Function)
433      @ Main.PkgTests.Utils ~/build/JuliaLang/Pkg.jl/test/utils.jl:18
434    [9] top-level scope
435      @ ~/build/JuliaLang/Pkg.jl/test/new.jl:1828
436   [10] top-level scope
437      @ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Test/src/Test.jl:1144
438   [11] top-level scope
439      @ ~/build/JuliaLang/Pkg.jl/test/new.jl:1821
440   [12] include(mod::Module, _path::String)
441      @ Base ./Base.jl:389
442   [13] include(x::String)
443      @ Main.PkgTests ~/build/JuliaLang/Pkg.jl/test/runtests.jl:3
444   [14] top-level scope
445      @ ~/build/JuliaLang/Pkg.jl/test/runtests.jl:16
446   [15] include(fname::String)
447      @ Base.MainInclude ./client.jl:444
448   [16] top-level scope
449      @ none:6
450   [17] eval(m::Module, e::Any)
451      @ Core ./boot.jl:360
452   [18] exec_options(opts::Base.JLOptions)
453      @ Base ./client.jl:261
454   [19] _start()
455      @ Base ./client.jl:485
456Test Summary: | Pass  Error  Total
457precompile    |    2      1      3
458ERROR: LoadError: LoadError: Some tests did not pass: 2 passed, 0 failed, 1 errored, 0 broken.
459in expression starting at /home/travis/build/JuliaLang/Pkg.jl/test/new.jl:1
460in expression starting at /home/travis/build/JuliaLang/Pkg.jl/test/runtests.jl:3
461ERROR: Package Pkg errored during testing
462Stacktrace:
463 [1] pkgerror(msg::String)
464   @ Pkg.Types ~/build/JuliaLang/Pkg.jl/src/Types.jl:52
465 [2] test(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}; coverage::Bool, julia_args::Cmd, test_args::Cmd, test_fn::Nothing)
466   @ Pkg.Operations ~/build/JuliaLang/Pkg.jl/src/Operations.jl:1632
467 [3] test(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}; coverage::Bool, test_fn::Nothing, julia_args::Cmd, test_args::Cmd, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
468   @ Pkg.API ~/build/JuliaLang/Pkg.jl/src/API.jl:334
469 [4] #test#62
470   @ ~/build/JuliaLang/Pkg.jl/src/API.jl:71 [inlined]
471 [5] test(; name::Nothing, uuid::Nothing, version::Nothing, url::Nothing, rev::Nothing, path::Nothing, mode::Pkg.Types.PackageMode, subdir::Nothing, kwargs::Base.Iterators.Pairs{Symbol, Bool, Tuple{Symbol}, NamedTuple{(:coverage,), Tuple{Bool}}})
472   @ Pkg.API ~/build/JuliaLang/Pkg.jl/src/API.jl:87
473 [6] top-level scope
474   @ none:1
475The command "julia --project --check-bounds=yes -e 'import Pkg; Pkg.build(); Pkg.test(; coverage=true)'" exited with 1.
476
477
478Done. Your build exited with 1.

[DilumAluthge]

@ianshmean Will the CI errors that I'm seeing in this PR will be fixed by #2091?

[IanButterworth]

Indeed. #2091 also includes the fix from #2102 and an additional related fix

[DilumAluthge]

Alright, this is good to go assuming CI passes.

[DilumAluthge]

Hmmmm. @ianshmean Any chance you know what's causing these new CI failures?

[IanButterworth]

I think this needs a rebase

[DilumAluthge]

Alright, looks like tests are finally passing.

[DilumAluthge]

@fredrikekre Is this good to merge now?

[fredrikekre]

Maybe add a test?

[DilumAluthge]

Maybe add a test?

Good idea. Done.

[DilumAluthge]

Bump.

[DilumAluthge]

CI failures are due to Pkg server woes.

[KristofferC]

Think you need to be a bit careful with string indexing, for example:

julia> x = "α.jl"
"α.jl"

julia> message = "`$x` is not a valid package name"
"`α.jl` is not a valid package name"

julia> if endswith(lowercase(x), ".jl")
           message *= ". Perhaps you meant `$(x[1:(end-3)])`"
       end
ERROR: StringIndexError("α.jl", 2)
Stacktrace:
 [1] string_index_err(::String, ::Int64) at ./strings/string.jl:12
 [2] getindex(::String, ::UnitRange{Int64}) at ./strings/string.jl:250
 [3] top-level scope at REPL[4]:2

[StefanKarpinski]

Using chop(; tail=3) should be safe. I'm still unclear why we don't just do the right operation instead of lecturing the user in this case. It's not like Foo.jl is a valid package name anyway.

[KristofferC]

I think we do that in the repl.

[StefanKarpinski]

Fair enough. Makes sense to be stricter in the API.

[DilumAluthge]

Good catch on the string indexing. I've changed it to use chop(x; tail=3).

[DilumAluthge]

I think we do that in the repl.

This is correct.

(@v1.5) pkg> add Example.jl
  Resolving package versions...
  Installed Example ─ v0.5.3
Updating `~/.julia/environments/v1.5/Project.toml`
  [7876af07] + Example v0.5.3
Updating `~/.julia/environments/v1.5/Manifest.toml`
  [7876af07] + Example v0.5.3

Makes sense to be stricter in the API.

Agreed.