Running and Debugging Tests

Index of All Documentation » Wing Pro Reference Manual » Unit Testing »

Tests can be run and debugged from the Testing menu, in the following ways:

  • Run All Tests runs all the unit tests listed in the Testing tool.
  • Run Tests in Current File runs all the tests found in the current editor.
  • Run Tests at Cursor runs the test or tests at the caret or selection in the current editor
  • Run Failed Tests reruns all the tests marked as failed in the Testing tool.
  • Run Tests Again reruns all the tests that were run the last time tests were run.

Test files or individual tests may be selected in the Testing tool and run with the Run Tests button or using the items in the right-click context menu.

To stop running tests, press Abort Tests in the Testing tool or select Abort Running Tests from the Testing menu.

To clear the previous test results from the Testing tool, use Clear Results in the right-click context menu.


For each of the run options, there is an equivalent debug option that will run the tests in the debugger. These are in the Debug group of the Testing menu.

When tests are debugged, output goes to the Debug I/O tool and the contents of the Testing tool are not updated with the results of the test.

Unexpected Exceptions

Some testing frameworks such as pytest may stop at internal exceptions that should be ignored by clicking on Ignore this exception location in the Exceptions tool. This occurs when the testing framework raises and then handles AssertionError in order to probe the capabilities of the running Python. By default, Wing will always stop on assertions, even if they are handled, because in most cases a failing assertion indicates a bug in code. Once ignored, Wing won't stop on these internal exceptions again and debugging can proceed as usual.

Execution Options

There are several options available for how Wing runs unit tests.

Process Model

When multiple test files are run at once, they may be run in a separate process for each file (the default), or all test files in one directory may be run in a single process. This is selected with Process Model under the Testing tab of Project Properties.

In the Per-Module model, Wing is running the equivalent of the following command line:

cd /path/to/files
python -m unittest
python -m unittest

In the Per-Package model, Wing is instead running the equivalent of:

cd /path/to/files
python -m unittest

In both cases all tests should be run, but two processes are used in the first case and only one in the second case. Which model you choose depends on the requirements of your test suite.

Running Tests Concurrently

Two or more test processes may be run in parallel by increasing the Number of Processes under the Testing tab of Project Properties. This can increase performance on systems with multiple CPU cores, but may introduce problems if the tests do not handle concurrency well.

Running Test Packages

When test files that are located in a package (a directory that contains, they may be loaded either as package modules, or as top-level modules. Each testing framework defines a default behavior for this case, but this can be overridden using Run as Package Modules under the Testing tab of Project Properties.

When files are loaded individually as package modules, Wing is running the equivalent of:

python -m unittest package.module

When files are loaded as a top-level package, Wing is running the equivalent of:

python -m unittest module