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Making a package

Now that our code is getting more complex, it is time to make it into a package.

We start by making module UtilityFunctions into a package, so we can reuse it more easily.

Since we plan to put this up on github (for you to download), the package name must be unique (in my github repo, at least). So we will name all of the packages that we create for this class with an 890 suffix.

Generic instructions for creating packages are here.

It is helpful to have a github account and put your packages there. But you can skip this step for the purposes of this class.

Disclaimer: I have not tried to create a package without github info!

Generating the package

The most common approach is PkgTemplates. It works like this:

In your base environment: pkg> add PkgTemplates. This is now always available.

Now let's generate a UtilityFunctions890 package.

  1. cd to the directory where all of your Econ890 code lives.
  2. Make a template.
  3. Create the package.
  4. Add the source code and tests.
  5. Add dependencies.
  6. Run tests.

Details for my case:

julia> econDir = "/Users/lutz/Documents/julia/Econ890";
julia> cd(econDir);
julia> using PkgTemplates
julia> gitIgnore = ["*.jl.cov", "*.jl.*.cov", "*.jl.mem", "/deps/deps.jl", "/docs/build"];
julia> t = Template(; dir = econDir,
               plugins = [
                       Git(; jl = false, ignore = gitIgnore),
julia> t("UtilityFunctions890")

[ Info: Running prehooks
[ Info: Running hooks
  Activating environment at `~/Documents/julia/Econ890/UtilityFunctions/Project.toml`
    Updating registry at `~/.julia/registries/General`
    Updating registry at `~/.julia/registries/registryLH`
    Updating git-repo ``
  No Changes to `~/Documents/julia/Econ890/UtilityFunctions/Project.toml`
  No Changes to `~/Documents/julia/Econ890/UtilityFunctions/Manifest.toml`
Precompiling project...
  1 dependency successfully precompiled in 1 seconds
  Activating environment at `~/.julia/environments/v1.6/Project.toml`
[ Info: Running posthooks
[ Info: New package is at /Users/lutz/Documents/julia/Econ890/UtilityFunctions

The package has now been created.

Check that you have a new folder UtilityFunctions890 with sub-folders src and test.

After creating the package, copy the contents of utility.jl into UtilityFunctions890.jl.

Copy the tests into test/runtests.jl.

We now need to modify those files a little to reflect the fact that the module UtilityFunctions890 is now a package. In this case, all we need to do is remove the lines

# This is one reason why packages work better.
using .UtilityFunctions

in the runtests.jl file.

Add dependencies (e.g., Pkg.add("Random")) until ] test works:

julia> Pkg.activate("UtilityFunctions890")
  Activating environment at `~/Documents/julia/Econ890/UtilityFunctions890/Project.toml`
julia> Pkg.add("Random")
julia> using UtiltyFunctions890

Now run the tests: pkg> test. And Bob is your uncle.