When can the NoTestRun test level be applied?

The NoTestRun test level is specifically designed to be applied in development environments. This is because it is used to skip the execution of tests during deployment when moving changes, such as metadata or configuration, that do not require testing. In a development context, the focus is often on rapid iterations and quick deployments, where automated testing may not be necessary or relevant due to the nature of the changes being made.

In production environments, however, running tests is a critical component to ensure the stability and reliability of the application after updates. Similarly, in staging environments, which are intended to closely mirror production, testing is also essential. Therefore, using the NoTestRun level in those contexts would not be appropriate, as it could bypass important checks that help catch potential issues before reaching end-users. Thus, the main utility of the NoTestRun level is found in development environments where the emphasis is on development speed rather than comprehensive testing.