Bash completion for Pythons unittest

Running single test cases with the unittest module is a bit fiddly. At least for me it often looks a bit like this:

I know that the test resides somewhere in the tests directory. Therefore, I need to find the correct file: tests/test_foo.py. But damn it! There are multiple test case classes in it. But I only want to run one of them. So I type: python -m unittest tests.test_foo.SomeFancyTestCase. Now I notice that this test case has multiple methods and each method takes ages to complete. But I only want to run this one test case that is repeatedly failing. So I need to open the file in order to get the full method name. Nice, the command now looks like this: python -m unittest tests.test_foo.SomeFancyTestCase.test_a_specific_edge_case_with_a_long_name If I made a mistake during copy & paste I get an unhelpful error.

As long as running python -m unittest discover is sufficient this isn't a problem. But there are situations when this is not desired:

• the whole test suite takes a long time to complete
• some test cases do not run on my machine locally
• the application that is being tested is overly chatty and I only want logs regarding this one test case
• ...

Therefore, I created this little helper script to add Bash autocompletion.

How does it work?

The program looks recursively for test case files matching the test_*.py pattern relative to the current working directory. It parses each file into an abstract syntax tree AST to offer completions for class names and/or method names.

The unittest module expects the identifier of a test case in the following format:

<MODULE>.<TEST_CLASS>.<TEST_METHOD>

where <TEST_CLASS> and <TEST_METHOD> are additional specifications to limit the number of executed tests. But these are optional.

Calling unittest-autocomp without any arguments will print all test case files relative to the current working dir:

$ unittest-autocomp
test.test_completions test.test_utils

Calling unittest-autocomp with a full path to a test case file will print all classes of this file:

$ unittest-autocomp test.test_completions.

test.test_completions.MethodnameCompletionTestCase test.test_completions.ClassnameCompletionTestCase test.test_completions.ModuleCompletionTestCase

(The trailing dot is required, so that the program knows to search the file)

Calling unittest-autocomp with a full path to a unittest class will print all test methods of that given class:

$ unittest-autocomp test.test_completions.MethodnameCompletionTestCase.


test.test_completions.MethodnameCompletionTestCase.test_completion_with_empty_partial test.test_completions.MethodnameCompletionTestCase.test_completion_with_only_folder_or_module test.test_completions.MethodnameCompletionTestCase.test_completion_with_missing_classname test.test_completions.MethodnameCompletionTestCase.test_completion_with_only_classname test.test_completions.MethodnameCompletionTestCase.test_completion_with_only_classname_and_half_method_name test.test_completions.MethodnameCompletionTestCase.test_completion_with_only_full_method_name

(The trailing dot is required, so that the program knows to search the class for methods)

Installation?

1. Make sure bash-completion is installed:
   • sudo apt install bash-completion
2. Install this module:
   • pip install unittest-autocomp
3. Activate the completion:
   • paste the file: ./unittest-completion to /etc/bash_completion.d:
     • sudo wget https://github.com/M0r13n/unittest-autocomp/blob/main/unittest-completion -P /etc/bash_completion.d

By default this installation will yield completions for the command python -m unittest. If you invoke the unittest module otherwise you need to change the line CMD="python -m unittest" locally on your machine to match your invocation.