importing go files in same folder

Question

I am having difficulty in importing a local go file into another go file.

My project structure is like something below

-samplego
--pkg
--src
---github.com
----xxxx
-----a.go
-----b.go
--bin

I am trying to import a.go inside b.go. I tried the following,

import "a"
import "github.com/xxxx/a"

None of these worked..I understand I have to meddle up with GOPATH but I couldn't get it right. Presently my GOPATH is pointing to samplego(/workspace/samplego).I get the below error

cannot find package "a" in any of:
/usr/local/go/src/pkg/a (from $GOROOT)
/workspace/samplego/src/a (from $GOPATH)

Also, how does GOPATH work when these source files are imported into another project/module? Would the local imports be an issue then? What is the best practice in this case - is it to have just one go file in module(with associated tests)?

Any number of files in a directory are part of the same package from the start. (And they need to have the same package a declaration at the top.) — twotwotwo
Thanks @twotwotwo...Could you let me know how to solve the above issue? Also, when we have multipe go files in a package should the import follow full path eg. github.com/xxxx/a or just a would do — g0c00l.g33k
For Go modules, files in the same directory are still part of the same package, still need to have the same package name (e.g., package foo), and still do not need to directly import each other. This answer covers this a bit more for Go modules, including how to import packages in the same module under Go modules. — typical182

twotwotwo twotwotwo · Accepted Answer · 2014-11-15T04:03:04

Any number of files in a directory are a single package; symbols declared in one file are available to the others without any imports or qualifiers. All of the files do need the same package foo declaration at the top (or you'll get an error from go build).

You do need GOPATH set to the directory where your pkg, src, and bin directories reside. This is just a matter of preference, but it's common to have a single workspace for all your apps (sometimes $HOME), not one per app.

Normally a Github path would be github.com/username/reponame (not just github.com/xxxx). So if you want to have main and another package, you may end up doing something under workspace/src like

github.com/
  username/
    reponame/
      main.go   // package main, importing "github.com/username/reponame/b"
      b/
        b.go    // package b

Note you always import with the full github.com/... path: relative imports aren't allowed in a workspace. If you get tired of typing paths, use goimports. If you were getting by with go run, it's time to switch to go build: run deals poorly with multiple-file mains and I didn't bother to test but heard (from Dave Cheney here) go run doesn't rebuild dirty dependencies.

Sounds like you've at least tried to set GOPATH to the right thing, so if you're still stuck, maybe include exactly how you set the environment variable (the command, etc.) and what command you ran and what error happened. Here are instructions on how to set it (and make the setting persistent) under Linux/UNIX and here is the Go team's advice on workspace setup. Maybe neither helps, but take a look and at least point to which part confuses you if you're confused.

importing go files in same folder

6 Answers