[NEW EXAMPLE] ErrorProne - Test Helper

[ainzzorl]

General

• Project name: ErrorProne
• Example name: Testing bug checkers in ErrorProne
• Project home page: https://github.com/google/error-prone
• Programming language(s): Java
• Frameworks, libraries used: JUnit, Truth

Description

Error Prone is a static analysis tool for Java that catches common programming mistakes at compile-time. It's comprised of hundreds of mostly independent bug checkers.

They employ a clever test helper to streamline testing these checkers, in a DSL-like fashion.

Links

• Test Helper
• Example usage (checker input is inlined)
• Example usage (checker input is read from another file)

What makes it interesting

• Taken from a popular, mature project, maintained by a major tech company.
• Example of testing things that are non-trivial to test.
• DSL-like API.
• Quite common pattern among any tools that do code analysis - see below.

Other

Many related products - linters, bug checkers, etc. - implement very similar patterns.

E.g. SonarQube's CheckVerifier, Rubocop's ExpectOffence.

[ainzzorl]

Draft: https://github.com/ainzzorl/goodcode/blob/4f5b4e11c240077fcfbe8a6223e199178eedf292/articles/error-prone-test-helper.md

[ainzzorl]

Before publishing:

• Tags: maybe "test-helper"?
• Backticks and links for class names.
• Forgot to include doTest?

[ainzzorl]

Updated and set to PUBLISHED.