Building Enterprise JavaScript Applications

Readability

With dependency injection, every dependency must be a parameter of the function. Thus, if the module has 20 dependencies, it'll need to have 20 parameters. This can make the module hard to read.

Often, you'll have a single root file where every dependency is imported, instantiated, and injected; these dependencies would then be passed down to child functions, and their child functions, and so on. This means for a developer to find the source of the dependency, he/she would have to follow the trail of function calls leading up to the root where the dependency is originally injected. This could be three or four function calls, or it might be a dozen.

Generally speaking, the more abstraction layers there are in a project, the harder ...