Question about importing dependencies of package

General Usage
1

I am developing a Julia package, say “PackA.jl”. It depends on many other packages, for example, “JSON.jl”.

I put JOSN both to Project.toml and REQUIRE.

In the main source file, “PackA.jl”, there’s a line to use JSON:

using JSON

Then I start julia REPL like this, in the root dir of PackA.jl:

julia --project=.

And:

julia> using JSON
ERROR: ArgumentError: Package JSON not found in current path:
- Run `import Pkg; Pkg.add("JSON")` to install the JSON package.

Stacktrace:
 [1] require(::Module, ::Symbol) at ./loading.jl:876

julia> using PackA.JSON
julia> using JSON
ERROR: ArgumentError: Package JSON not found in current path:
- Run `import Pkg; Pkg.add("JSON")` to install the JSON package.

Stacktrace:
 [1] require(::Module, ::Symbol) at ./loading.jl:876

julia> JSON
JSON

JSON can only be imported through PackA but can’t be imported directly. Is this by design?

Thanks.

2

Yes it is.

What packages PackA depends on is an implementation detail that you as a user should not see. If you want to using JSON should should add JSON as a dependency, not rely on some other package to make it available for you.

3

Thanks.