gemtest-webapp 1.0.1

Visualize metamorphic test cases from gemtest

gemtest-webapp

The gemtest-webapp extends the gemtest framework by a web application that allows you to inspect and analyze your gemtest test metamorphic test runs. It features a tabular test report and a metamorphic test case detail view where one can examine all artifacts of a single executed metamorphic test case.

First, run a gemtest test suite with the --html-report flag:

$ pytest --html-report

Then, install gemtest-webapp via pip install gemtest-webapp and run it with the path to the gemtest_results folder created by a gemtest pytest run. Usually, this folder is created in the directory from which pytest was executed.

$ gemtest-webapp --results-dir gemtest_results/

Custom Visualizers

If the input or output of the system under test you are testing is not nicely presentable by a string, one can create a visualizer function visualaizing input and output on a static html page. For this, the system_under_test decorator can take functions as optional arguments, such as:

@gmt.system_under_test(
    visualize_input=visualizer.visualize_input,
    visualize_output=visualizer.visualize_output
)

The visualize_input function returns a string that is then embedded in the HTML:

def visualize_input(self, sut_input: Any, **kwargs) -> str:
        mtc = kwargs["mtc"]
        index = kwargs["index"]
        run_id = kwargs["run_id"]
        position = kwargs["position"]

        name = f"{mtc.report.sut_name}." \
               f"{mtc.report.mr_name}." \
               f"{mtc.report.mtc_name}." \
               f"{position}_{index}.png"

        image = (self.transform(sut_input).clone() * 255).view(96, 96)
        plt.clf()
        plt.imshow(image, cmap="gray")
        plt.axis("off")
        return self.savefig(self.image_folder, name, run_id)

Webapp

In the html-report, displayed by the gemtest-webapp, one can see the information of all passed, failed, and skipped test cases as well as filter by metamorphic relation, system under test, and test verdict.

MTC Detail View

When clicking on the link/name of a specific metamorphic test case, the metamorphic test case detail view opens. It visualizes the inputs and outputs of the system under test if a custom visualizer is passed. This makes investigating why one's test case passed or failed faster and more intuitive.

Citation

If you find the gemtest or gemtest-webapp framework useful in your research or projects, please consider citing it:

@inproceedings{speth2025,
    author = {Speth, Simon and Pretschner, Alexander},
    title = {{GeMTest: A General Metamorphic Testing Framework}},
    booktitle = "Proceedings of the 47th International Conference on Software Engineering, (ICSE-Companion)",
    pages = {1--4},
    address = {Ottawa, ON, Canada},
    year = {2025},
}

License

MIT License