What does the '.' (dot or period) in a Go import statement do?

user_586750 0
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In the Go tutorial, and most of the Go code I've looked at, packages are imported like this:

import (
    "fmt"
    "os"
    "launchpad.net/lpad"
    ...
)

But in http://bazaar.launchpad.net/~niemeyer/lpad/trunk/view/head:/session_test.go, the gocheck package is imported with a . (period):

import (
    "http"
    . "launchpad.net/gocheck"
    "launchpad.net/lpad"
    "os"    
)

What is the significance of the . (period)?

go import
3 Answers

This should only be used in testing.

Here is some documentation in golang's wiki

If you've generated some mock code such as with mockgen and it imports your package code, and then your testing package also imports your package code, you get a circular dependency (Something golang chooses to let the user to decide how to resolve).

However, if inside your testing package you use dot notation on the package you're testing then they are treated as the same package and there is no circular dependency to be had!

user_49742610
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