6. Risky Tests

PHPUnit can perform the additional checks documented below while it executes the tests.

Useless Tests

PHPUnit is by default strict about tests that do not test anything. This check can be disabled by using the --dont-report-useless-tests option on the command line or by setting beStrictAboutTestsThatDoNotTestAnything="false" in PHPUnit’s configuration file.

A test that does not perform an assertion will be marked as risky when this check is enabled. Expectations on mock objects count as an assertion.

Unintentionally Covered Code

PHPUnit can be strict about unintentionally covered code. This check can be enabled by using the --strict-coverage option on the command line or by setting beStrictAboutCoversAnnotation="true" in PHPUnit’s configuration file.

A test that is annotated with @covers and executes code that is not listed using a @covers or @uses annotation will be marked as risky when this check is enabled.

Furthermore, by setting forceCoversAnnotation="true" in PHPUnit’s configuration file, a test can be marked as risky when it does not have a @covers annotation.

Output During Test Execution

PHPUnit can be strict about output during tests. This check can be enabled by using the --disallow-test-output option on the command line or by setting beStrictAboutOutputDuringTests="true" in PHPUnit’s configuration file.

A test that emits output, for instance by invoking print in either the test code or the tested code, will be marked as risky when this check is enabled.

Test Execution Timeout

A time limit can be enforced for the execution of a test if the PHP_Invoker package is installed and the pcntl extension is available. The enforcing of this time limit can be enabled by using the --enforce-time-limit option on the command line or by setting enforceTimeLimit="true" in PHPUnit’s configuration file.

A test annotated with @large will fail if it takes longer than 60 seconds to execute. This timeout is configurable via the timeoutForLargeTests attribute in the configuration file.

A test annotated with @medium will fail if it takes longer than 10 seconds to execute. This timeout is configurable via the timeoutForMediumTests attribute in the configuration configuration file.

A test annotated with @small will fail if it takes longer than 1 second to execute. This timeout is configurable via the timeoutForSmallTests attribute in the configuration file.

Note

Tests need to be explicitly annotated by either @small, @medium, or @large to enable run time limits.

Global State Manipulation

PHPUnit can be strict about tests that manipulate global state. This check can be enabled by using the --strict-global-state option on the command line or by setting beStrictAboutChangesToGlobalState="true" in PHPUnit’s configuration file.