TDD workflow in Julia language (NOTE: mostly personal preferences).

00_julia_TDD_workflow.md

Structure, naming, setup

In the project directory, open in LightTable:

• ModuleName.jl with functions under development (Capitalize jl-file names containing modules, match file and module names)
• usingfile.jl that does include("ModuleName.jl") (which allows reloading without Julia restart, see FAQ)

In the ./test/ sub-directory, put the file with FactCheck tests for ModuleName functions: collect all tests into one file named modulename.jl, i.e. the same as source but without capitalization and residing in the testing sub-directory. Open it in LightTable as well.

Test-driven development steps

1. Open a terminal with interactive Julia REPL in the project directory
2. using FactCheck
3. include("ModuleName.jl"); include("./test/modulename.jl")

Proceed with the TDD write test, fail, edit code, pass workflow re-running the last steps above after code edits. IMPORTANT: always remember to reload the module after edits, include("ModuleName.jl") (hence 2 commands are chained in step 3 above). Otherwise tests will apply to the previously loaded version. Seems obvious but easy to skip my mistake in practice.

10_ModuleName.jl

## what the module does
module ModuleName

using Something

export myfunc1, myfunc2

function myfunc1()
  1
end

function myfunc2()
  2
end

end # module

20_usingfile.jl

## what we are trying to accomplish
include("ModuleName.jl")
using ModuleName

myfunc1()
myfunc2()

30_modulename.jl

## resides in ./test/ sub-directory

facts("Scope A") do
  @fact ModuleName.myfunc1() => 1
end

facts("Scope B") do
  @fact ModuleName.myfunc2() => 2
end

# group fact checks in top-level scopes and sub-level contexts;
# good examples:
#  https://github.com/zachallaun/FactCheck.jl/blob/master/src/example_factcheck.jl
#  https://github.com/JuliaStats/TimeSeries.jl/blob/master/test/timearray.jl