Break up go project into subfolders

Question

I want to break my project up to subfolders.

I want this code structure:

├── main.go
└── models
    └── user.go

Where main.go is:

Answer 1

I recently achieved this by using go modules.

Golang introduced preliminary opt-in support for modules as of go v1.11.1 which is intended to completely remove the, frankly, absurd $GOPATH necessity. Not only can you now have versioned dependencies in any normal directory such as ~/development, but you can basically have something that looks like namespaces and sub-directories. You can enable this feature by invoking the go command with the following environment variable: GO111MODULE=on.

Go v1.11.3 expects to enable modules by default and is slated for August 2019.

---

Here is an example directory structure (that you might find typically in some other languages).

~/Dev/my-app
 ├── src/
 │   ├── one/
 │   │   ├── two/
 │   │   │   └── two.go
 │   │   └── one.go
 │   └── zero.go
 ├── go.mod
 └── app.go

The application is called my-app, which will be the module name for app.go. We define this once in go.mod and then each of all the other go files in subdirectories will automatically be importable as if they were namespaced.

Given the above, two.go, assuming it contains a function named Two, will be importable in app.go by using my-app/src/one/two.

Here's what you need to do to achieve this:

go.mod

module my-app

two.go

package two

func Two() string {
    return "I'm totally not supposed to be using go modules for this"
}

app.go

package main

import "my-app/src/one/two"

func main() {
    two.Two()
}

If you were to place another file within two/, then you would simply use two.TheNewFunc() as long as you made TheNewFunc() available within the new file.

I created a very simple GitHub repo which you can check out as a demonstration.