Eye of Ra

Build Status

This package is aimed at removing the manual aspects of the typical programming change-check cycle, usually invoked by

  1. edit
  2. save
  3. <alt-tab>
  4. <up-arrow><enter>
  5. curse/scream/yell/despair
  6. <alt-tab>
  7. Continue from step 1...


Invoke the macro @observe on a function call. The documentation is:

@observe func(args... ; kwds...)

Use Revise to "observe" changes to a functions behaviour. This will track the return values and the stdout/stderr of the function.


  • This only tracks stdout, stderr output using redirect_stdxxx. Many functions (e.g. display) will not output to the current stdout and so will not be captured.
  • "Repeats" are recorded. Two calls repeat, when they have the same output.
  • Currently, any change to the function's module will cause the function to be retested.
  • This will probably only work on linux at the moment...

Example output


Example with exception


Future ideas

  • Diffs of output and returned values.
  • Multiple input arguments to test several cases at once.


This idea was inspired by Brett Victor's talk "Inventing on Principle": https://www.youtube.com/watch?v=8QiPFmIMxFc

Emacs support

See the emacs package julia-funcobs for an IDE-like interface with julia-repl. Includes image support from Plots.jl.



Why "Eye of Ra"?

  • Watches over.
  • Protective.
  • Can get "out of control"