Open source

JUnit Jupiter best practices

Recipe IDorg.openrewrite.java.testing.junit.JupiterBestPractices

Artifactorg.openrewrite.recipe:rewrite-testing-frameworks

Applies best practices to tests.

Composite recipeJavajunittestingModerne Source Available License

Try in PlatformTry this recipe in the Moderne platform. Not a user yet? You’ll get a no-setup demo environment, with nothing to install or configure.

Definition

Preconditions1

• Singleton

Recipes22

22 recipes

• Migrate Hamcrest assertions to JUnit Jupiter
• Statically import JUnit Jupiter assertions
• Remove JUnit 5 static Assertions imports in Kotlin when wildcard import is present
• Clean Up Assertions
• Replace @CsvSource with @ValueSource for single method arguments
• Remove unnecessary assertEquals delta argument for integral types
• Replace JUnit assertTrue(false) and assertFalse(true) with fail()
• Remove JUnit assertTrue(true) and assertFalse(false)
• Kotlin test methods should have return type Unit
• Remove test prefix from JUnit 5 tests
• Simplify throws statements of tests
• Remove public visibility of JUnit 5 tests
• Test methods should have void return type
• Add missing @ParameterizedTest annotation when @ValueSource is used or replace @Test with @ParameterizedTest
• Remove duplicates uses of @TestTemplate implementations for a single method
• Replace fail() in try-catch blocks with Assertions.assertDoesNotThrow(() -> { ... })
• Make lifecycle methods non private
• Applies JUnit 5 assertThrows on last statement in lambda block only
• assertTrue(x instanceof y) to assertInstanceOf(y.class, x)
• Make implausibly long @Timeout values explicit in minutes
• Use JUnit5's assertSame or assertNotSame instead of assertTrue(... == ...)
• Remove JUnit Jupiter migrationsupport

Usage

Run this recipe

This recipe has no required configuration options. Users of Moderne can run it via the Moderne CLI.

You will need to have configured the Moderne CLI on your machine before you can run the following command.

shell

mod run . --recipe JupiterBestPractices

If the recipe is not available locally, then you can install it using:

mod config recipes jar install org.openrewrite.recipe:rewrite-testing-frameworks:3.40.0

Data tables

Source files that had results

org.openrewrite.table.SourcesFileResults

Source files that were modified by the recipe run.

Column	Description
Source path before the run	The source path of the file before the run. null when a source file was created during the run.
Source path after the run	A recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Parent of the recipe that made changes	In a hierarchical recipe, the parent of the recipe that made a change. Empty if this is the root of a hierarchy or if the recipe is not hierarchical at all.
Recipe that made changes	The specific recipe that made a change.
Estimated time saving	An estimated effort that a developer to fix manually instead of using this recipe, in unit of seconds.
Cycle	The recipe cycle in which the change was made.

Source files that had search results

org.openrewrite.table.SearchResults

Search results that were found during the recipe run.

Column	Description
Source path of search result before the run	The source path of the file with the search result markers present.
Source path of search result after run the run	A recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Result	The trimmed printed tree of the LST element that the marker is attached to.
Description	The content of the description of the marker.
Recipe that added the search marker	The specific recipe that added the Search marker.

Source files that errored on a recipe

org.openrewrite.table.SourcesFileErrors

The details of all errors produced by a recipe run.

Column	Description
Source path	The file that failed to parse.
Recipe that made changes	The specific recipe that made a change.
Stack trace	The stack trace of the failure.

Recipe performance

org.openrewrite.table.RecipeRunStats

Statistics used in analyzing the performance of recipes.

Column	Description
The recipe	The recipe whose stats are being measured both individually and cumulatively.
Source file count	The number of source files the recipe ran over.
Source file changed count	The number of source files which were changed in the recipe run. Includes files created, deleted, and edited.
Cumulative scanning time (ns)	The total time spent across the scanning phase of this recipe.
Max scanning time (ns)	The max time scanning any one source file.
Cumulative edit time (ns)	The total time spent across the editing phase of this recipe.
Max edit time (ns)	The max time editing any one source file.