Avoiding @Value Initialization for Existing Instances

[vnayar]

For context, when autowiring an instance that has already been pre-defined, the system avoids @Autowire for values that have already been set. This is very useful when adding fake components during testing.

This is seen in the test here:

poodinis/test/poodinis/containertest.d

Line 148 in 87c036d

// Test autowiring does not autowire member where instance is non-null

However, the same behavior is not seen for members that have the @Value annotation. Those values get re-initialized. Thus, if you have an autowired component, such as "MyAppConfig" or something like that with many @Value properties, and then I try to inject an existing instance in a test, e.g. container.register!MyAppConfig.existingInstance(testConfig);, when the rest of the code tries to resolve that dependency, the @Value annotations will be processed again, and replace any values set for the test.

Is this a bug, or is it intended behavior with a known workaround? Can you disable re-evaluation of @Value annotations for existing instances that have been plugged into the DependencyContainer?

[mbierlee]

Hello @vnayar, thank you for bringing this to my attention. It seems that this is indeed a bug. Once an instance has been created, especially a singleton, there should be no need to re-inject values over and over. It sounds like this is a matter of things being done in the wrong order in the injection system. I will investigate further and create a fix when time allows.