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One year after switching from Java to Go

(glasskube.dev)
257 points pmig | 2 comments | 18 Feb 25 16:55 UTC | HN request time: 0s | source
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bryancoxwell ◴[18 Feb 25 23:29 UTC] No.43096481[source]▶
> But there are obviously work around solutions in the Go ecosystem. It uses the Context ctx, which we pass around functions in order to juggle data around in the application.

Man. This works. The context API allows/enables it. But I’d really recommend against passing data to functions via context. The biggest selling point of Go to me is that I can usually just look at anyone’s code and know what it’s doing, but this breaks down when data is hidden inside a context. Dependency injection is entirely possible without using the context package at all, interfaces are great for it.

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roncesvalles ◴[19 Feb 25 07:34 UTC] No.43099616[source]▶
IoC DI in Go is a massive antipattern and absolutely should not be done. Do NOT write Java/.NET style controllers in Go i.e. initializing an instance of a "controller" type with some instances of a "dependency" such as a store.

Just use the dependent package directly. Initialize the package once using init() or Init(). Rely on the built-in package dependency resolver system in Go, which will catch cyclic dependencies, call init() in topo order, and other such things.

Test using monkey-patching. Stop using interfaces just to be able to swap a real thing with a mock implementation. These are all symptoms of writing Java in Go.

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stpedgwdgfhgdd ◴[19 Feb 25 07:59 UTC] No.43099767[source]▶
I don't get the part on package. Often you want to use structs. (Instance vs static)

How would you construct an instance in a test that needs mock implementations?

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1. roncesvalles ◴[19 Feb 25 08:04 UTC] No.43099791[source]▶
Such an instance would just be a variable somewhere that would be initialized in some init() call when the program starts. Every user of that instance will use it directly (as opposed to storing a reference to it locally DI style).
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2. gf000 ◴[19 Feb 25 10:48 UTC] No.43100732[source]▶
So global mutable state? How wonderfully modern!