Test coverage checking when test driver is separate from the

Ruby
1

Hello,

I have a program compiler.rb, that compiles something.
The test driver is a separate program, that runs compiler.rb, then feeds
the results to a virtual machine, and checks if it gets expected
results.

Now I’d like to verify that every single line of compiler.rb is
covered by tests.
How can I make rcov merge information from multiple runs of compiler.rb
?

2

On Wed, Aug 23, 2006 at 08:32:09AM +0900, Tomasz W. wrote:

I have a program compiler.rb, that compiles something.
The test driver is a separate program, that runs compiler.rb, then feeds
the results to a virtual machine, and checks if it gets expected results.

Now I’d like to verify that every single line of compiler.rb is
covered by tests.
How can I make rcov merge information from multiple runs of compiler.rb ?

You can use the --aggregate option, which was added in 0.7.0.
Essentially, you just have to run your program using rcov with the
–aggregate FILE option:
rm -f coverage.data
rcov -t --no-html --aggregate coverage.data bin/compiler.rb – -args
–to --compiler.rb bar.src
rcov --aggregate coverage.data bin/compiler.rb – -some --other --args
foo.src

You can skip HTML report generation in all but the last run with
–no-html;
the -t (text summary) option stops rcov from complaining about the lack
of
files to analyze.

There’s some additional information about how to do it both manually and
with a
Rake task at
eigenclass.org

Note that --aggregate is fairly slow since all the execution count and
coverage information must be saved in the specified file, as well as the
code
that was loaded (since in a later execution different files could be
loaded/parsed).

3

On Wed, Aug 23, 2006 at 08:08:27PM +0900, Mauricio F. wrote:

On Wed, Aug 23, 2006 at 08:32:09AM +0900, Tomasz W. wrote:

I have a program compiler.rb, that compiles something.
The test driver is a separate program, that runs compiler.rb, then feeds
the results to a virtual machine, and checks if it gets expected results.

Now I’d like to verify that every single line of compiler.rb is
covered by tests.
How can I make rcov merge information from multiple runs of compiler.rb ?

You can use the --aggregate option, which was added in 0.7.0.
[…]

Sorry, I misread the first paragraph and answered somewhat aside of the
question.

In the case you describe, you could create a small wrapper that would
look
more or less like this:

#!/usr/bin/env ruby

system(“rcov”, “–aggregate”, “coverage.data”, “–no-html”, “-t”,
“compiler.rb”, “–”, *ARGV)
exit $?.exitstatus

Then you could select which script (the wrapper or the actual
compiler.rb) is
to be executed with a symlink.
Alternatively, you could change the driver to select the script or
execute
rcov with the appropriate arguments directly, but at that point you’d
have to
implement some way to specify whether rcov is to be used or not, if you
want
to allow both.

Hope this helps.