[ANN] EyeOfRa.jl for rapid function writing

Hi all,

To speed up my workflow, I’ve made a “continuous testing” package for seeing function output on every editor save called EyeOfRa.jl. This aims to make the edit/save/run loop of function writing/debugging more comfortable.

The package piggy backs off Revise.jl to notice when a module has been updated and reruns a given function, displaying the return value, its Type, run time and stdout/stderr. A difference in inferred type will also be noticed. In the future this will also show a diff of the outputs.

To use from the REPL, make sure Revise and EyeOfRa are imported, then call:

@observe some_func(...)

Now edit your code and save, and observe the changes in output.

For example, a call @observe MyModule.greet() could generate the following output:

Successful run:

Module code throwing an exception after a previous successful run, showing stacktrace and previous success:

I have also created an emacs package to interface with this through julia-mode and julia-repl, which is hosted at julia-funcobs. This allows for Plots.jl objects returned from functions to be displayed:

If anyone is interested in a similar implementation for VSCode or another editor, I eagerly await your pull request!

The inspiration for this package came from a talk by Brett Victor: Inventing on Principle.

I have described this as “continuous testing” but I’m sure there is a better term for this, as CT brings to mind CI testing in repositories, rather than local updates.