Fiat: an auto-Make-er

Fiat's a bit like autotest for make-managed projects.

Fiat monitors a make task's dependencies. Each time one of those dependencies changes, fiat executes the task, prints the results, and reports whether the process succeeded or failed.

• Ruby
• RubyGems

gem install fiat

If you haven't installed any gems before, you may need to add rubygems' directory to your $PATH.

fiat [task]

Suppose we're developing a little C program, and we'd like to automatically run it each time we make changes.

Sample Makefile:

all: hello_world.c
	gcc -o hello hello_world.c
run: my_proj
	./hello

We can execute:

$ fiat run
Running "make run" on changes...
gcc -o hello hello_world.c
./hello
Hello, world!

######################################## // <- this line should be green =)
...

Each time we save changes to my_proj.c, fiat will execute make run and print the results, followed by a line of hashes. This line is green if the program exited cleanly (with exit status == 0) and didn't include one of the failure terms (see below) or red if the program failed in some way. This makes it easy to tell at a glance whether our tests succeeded or failed.

If the output of a task includes one of the defined key terms (failure_terms), fiat interprets that run as a failure and prints the end-of-run bar in red.

In the same directory as the Makefile, we can optionally define a .fiatrc file which is interpreted when fiat is executed. In it we can set two variables:

• instruction -- the make task to be run. Defaults to "test".
• failure_terms -- a list of strings that imply failure if any of them appear in the program's output. Defaults to ["failed", "error"].

For example, the .fiatrc for the sample project above might look like:

failure_terms = []
instruction = "run"

Since we're not using a testing package, there's (probably) no reason to define failure_terms; we'll only get a red end-of-run bar when the program returns a non-zero exit status. However, the make task we're using is run, so setting instruction = "run" allows us to run fiat without arguments:

$ fiat
Running "make run" on changes...
gcc -o hello hello_world.c
./hello
Hello, world!

########################################
...

Alternately, suppose we're using make to manage an Erlang project with EUnit tests, and we'd like to know when our tests fail. The make task to execute our tests is fiat's default, test. For fiat's purposes, we'd like to define a failed test to be one in which the term "Failed:" appears.

So, our .fiatrc is just:

failure_terms = ["Failed:"]

Easy-peasy.

This thing's still very much a work-in-progress, so please feel free to shoot me an email if you love it/hate it/want me to fix something about it. =)