R - Reason Codes

Introduction

These output codes are associated with checks performed on your Java code by Diffblue Cover and highlight code issues that prevent tests being created.

R002 - Missing observers

There are no fields that could be asserted on. Add getters or make the fields package-private.

R003 - Test did not increase coverage

Information only.

R005 - Unable to load class

Please check that the class is available on your test runtime classpath. See our documentation for further guidance.

R006 - Static initializer failed

A static initializer threw an exception while trying to load a class. Make sure static initializers can be executed without throwing exceptions.

R007 - Class not accessible

Make sure all classnames are accessible from their targetPackage, for example by making them public.

R008 - Failed to instantiate class under test

Diffblue Cover was unable to construct an instance of someClass. Ensure there is a package-visible constructor or factory method that does not throw an exception for the class under test. If such a method is already present but Diffblue Cover does not find it, it can be specified using custom rules for inputs: custom-inputs See Working with code R008 for further troubleshooting of this issue.

R011 - Sandboxing policy violation

Diffblue Cover's default sandboxing policy disallowed test writing in order to prevent your code from damaging your system environment. Please see Working with code R011.

R012 - JNI sandbox policy violation

Diffblue Cover ran code in your project that tried to load a JNI library, violating the default security policy. See Java Native Interface to resolve this issue.

R013 - No inputs found that don't throw a trivial exception

Diffblue Cover tried to run the arrange/act section, but the method under test threw an error. Add constructors or factory methods that make it easier to construct fully initialized objects. Please see Working with code R013.

R014 - Test class file could not be loaded

The test class file could not be loaded. This is required for Diffblue Cover to inspect existing test classes. Ensure your project is compiled before using Diffblue Cover to write tests.

R020 - Temporary files were created but not deleted

Please ensure that temporary files are deleted in the method under test.

R021 - Missing Spring component

Diffblue Cover detected Spring on the classpath, but failed to load critical components while building the Spring context. Make sure these components can be loaded.

R023 - Out of memory

Diffblue Cover failed to create tests because it ran out of memory. See: Memory Management

R026 - Failed to create Spring context

Failed to create Spring context. Check to see if there are any missing environment variables or system properties. For detailed and further troubleshooting please see Working with code R026.

R027 - Missing beans when creating Spring context

Failed to create Spring context due to missing beans. Check to see if there are any missing environment variables or system properties. Also missing beans could be defined in Spring profiles that aren't used for test generation. For further detail troubleshooting Spring contexts please see Working with code R026. Otherwise, please contact Diffblue Support with details of the entire output message and the source code of the class under test.

R028 - Incomplete repository information

Diffblue Cover needs to understand the Data Type and the ID Type in order to write repository tests. Diffblue Cover also needs an ID Getter method that gets the identifier field from a Data Type instance, this should be annotated @Id and be of type ID Type. Alternatively, if using composite keys with @IdClass, the entity class must be annotated with @IdClass which must reference the ID Type. Finally, better tests can be written if a Save Method is found taking a Data Type instance and storing it in the repository.

Try extending CrudRepository with concrete type parameters, or if the class should not be considered a repository then annotate the class with the @NoRepositoryBean annotation.

R031 - Method may be time-sensitive

Diffblue Cover was only able to write tests that are time-sensitive. The assertions don't pass when run at an alternate date, time, and timezone. Try refactoring the method to take a java.time.Clock instance so that the time can be parameterized during testing. See Working with code R031 for details.

R032 - User requested skeleton tests only

Only skeleton tests have been created for this method, as requested by the user. These should be completed manually, as needed.

R033 - Missing Spring properties

Some classes in the Spring context have @Value annotations with placeholders or there are XML context files using placeholders that Diffblue Cover cannot resolve. Usually variables for such annotations are provided in *.properties files. Please check src/main/resources and src/test/resources. The default names for the files are application.properties and application-test.properties. If you use named Spring profiles please use application-<profile name>.properties files.

R035 - Unsupported virtual threads call detected

Diffblue Cover does not support writing tests for methods that use virtual threads.

R036 - CSRF protection enabled

Controller tests cannot be written because CSRF protection is enabled by Spring-security. Write a custom configuration to deactivate CSRF for unit tests, which can then be imported in the base class for your test.

R037 - Unable to use annotation value

Diffblue Cover was unable to write a test using a value specified by an annotation.

R038 - Spring repository tests skipped

Diffblue Cover skipped test creation for Spring repository. Check whether Spring boot tests are enabled. If they are not, enable them.

R039 - Unable to use factory method

Diffblue Cover was unable to generate a test using the specified factory method in the @InTestsMock annotation.

R040 - Unable to use factory method

Diffblue Cover was unable to generate a test using the specified factory method in the @InTestsUseFactories annotation.

R074 - Unable to create static mock

Mockito was unable to create a static mock for a class. Please review the underlying cause in the output message or log.

R081 - Exception in arrange section

Diffblue Cover was unable to construct an instance of the class under test because a step in the arrange section threw an exception.

R082 - Can't create a parameter for constructor

Diffblue Cover was unable to construct an instance. Diffblue Cover failed to create a parameter for the constructor or factory method call.

R083 - Can't find a suitable constructor

Diffblue Cover was unable to construct an instance. No suitable constructor or factory method found. Please check that the class under test has a non-private constructor or factory method.

R084 - Enum has no constants defined

Diffblue Cover was unable to test an instance of an enum as no constants are defined.

R085 - Unbounded loop in method under test

Diffblue Cover was unable to write a test that does not get into a potentially unbounded loop.

R086 - Unable to use custom base class

Diffblue Cover was unable to use the requested base class. Please check that the requested base class is public and has an accessible constructor.

R087 - Can't create required class instance

Diffblue Cover was unable to create an instance of a required class.

R088 - Method name is a reserved keyword

Diffblue Cover does not support methods with names that coincide with reserved keywords

R089 - Test class disabled

Diffblue Cover was configured to insert tests into existing test classes, but one of the test classes in question was disabled. Tests inserted into this class would not be run, and would therefore not be useful: they would not verify anything and not provide any coverage. Consider removing the annotation which disabled the test class, or disabling single tests instead of the whole class.

R090 - Failed to merge tests into test classes

Diffblue Cover was unable to merge generated tests into the existing test class. This can happen when the test file has structural issues or parsing conflicts. Use the @WriteTestsTo annotation to specify an alternative test class, or disable merge mode.