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World Congress 2021 • Jun 29, 2021

How To Test A Ball of Mud

Ryan Latta

Stop using mocks as painkillers for bad architecture. Learn how to tame your monolithic codebase by enforcing strict test independence and deleting obsolete failing tests.

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#1 about 3 min

Characteristics of a ball of mud ecosystem

How inherent unpredictability and high complexity make software systems nearly impossible to navigate.

#2 about 8 min

Writing system tests to verify operational infrastructure

Checking baseline server stability with basic scripts prevents wasted effort diagnosing functional errors.

#3 about 6 min

Rules for forcing unit testing into developer workflows

Enforcing the creation and immediate execution of two new tests per standard work item.

#4 about 3 min

Redefining the testing unit based on real design

Building tests around messy code blocks exposes practical coupling rather than idealized class isolation.

#5 about 4 min

Navigating the risks of mocking code dependencies

Overusing automated mocks hides underlying design flaws and risks validating a shadow implementation instead.

#6 about 2 min

Decommissioning neglected and failing legacy test suites

Continually failing or ignored tests should be deleted completely instead of wasting time restoring past context.

#7 about 7 min

Isolating test execution to achieve reliable feedback

Running random and consecutive executions helps distinguish test state dependency issues from actual code bugs.

#8 about 3 min

Introducing smoke tests for critical application use cases

Full-system verifications become valuable only after lower-level tests eliminate underlying environmental variables.

#9 about 4 min

Adopting a new paradigm to untangle software functionality

Reversing massive architectural decay requires fundamentally different and practically unintuitive practices like rigorous foundation testing.

#10 about 3 min

Handling problematic singletons within legacy software systems

Managing state and controlling component lifecycles requires creative workarounds in heavily coupled singleton patterns.

#11 about 4 min

Evaluating the utility of snapshot and parameterized tests

Extensive test iteration loops often complicate debugging compared to individually asserting explicit functional values.

#12 about 3 min

Unearthing extreme logic bugs embedded inside god classes

Bizarre application architectures sometimes require strange configuration hacks precisely just to reach encapsulated business logic.

Matching moments

4:21 min

Reimagining test automation dynamics as spinning top mechanisms

Leszek Włodarski Leszek Włodarski · WWC Europe 2026

8:22 min

Navigating legacy systems and unconventional software testing practices

Philipp-Alexander Blum · LIVE

3:02 min

Refactoring architectural messes like the big ball of mud

Mustafa Toroman · WWC 2021

6:24 min

Applying key software design rules to test code

Gil Zilberfeld · LIVE

1:35 min

Shifting to a culture of continuous proof and best practices

Sonja Nesic Sonja Nesic · WWC Europe 2026

4:00 min

Adopting test-driven design as a strategic development methodology

Mirjam Aulbach · WWC 2022

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