MockReset is extremely slow for large project in 1.5.x branch

[longwa]

Spring Boot 1.5.15

The line:

spring-boot/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockReset.java

Line 106 in bd482d7

if (ClassUtils.isPresent("org.mockito.internal.util.MockUtil", null)) {

...checks for the presence of Mockito on every call. This is executed before AND after each test for every bean in the context.

In spring-boot 2.0 this has already been refactored to check once in the ResetMocksTestExecutionListener and store the result in a static variable. It would be nice if this could be back ported to 1.5.x as well.

Our project has about 1500 beans and we run around 8,300 tests. This results in over 12 million calls to this method. Stubbing out the ResetMocksTestExecutionListener improves performance by about 10x.