Dependency Injection

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Guice Motivation

Dependency Injection is a Design Pattern

Advantages

1. Easy to write tests
   • e.g.: classes with database instances
2. Dependency is exposed by API signature, not hidden in the code
   • after adding a new dependency
     • no need to manually check the tests to find out which ones will fail
     • no need to worry about forgot initializing the new dependency in the code