unimport
unimport is a Go static analysis tool to find unnecessary import aliases.
Installation
go get -u github.com/alexkohler/unimport
Usage
Similar to other Go static anaylsis tools (such as golint, go vet) , unimport can be invoked with one or more filenames, directories, or packages named by its import path. Unimport also supports the ... wildcard.
unimport files/directories/packages
Currently, no flag are supported. A -w flag may be added in the future to automatically remove aliases where possible (Similar to gofmt's -w flag).
Purpose
As noted in Go's Code Review comments:
Avoid renaming imports except to avoid a name collision; good package names should not require renaming.
In the event of collision, prefer to rename the most local or project-specific import.
This tool will check if any import aliases are truly needed (by ensuring there is a name collision that would exist without the import alias). This tool will ignore import paths containing dashes and dots, as these are generally useful aliases while importing a specific revision. For example, in gometalinter, there are some imports like kingpin "gopkg.in/alecthomas/kingpin.v3-unstable". This is a reasonable import alias and will not be flagged.
Example
Running unimports on the Go source:
$ unimport $GOROOT/src/...
cmd/go/pkg.go:18 unnecessary import alias pathpkg
go/build/build.go:19 unnecessary import alias pathpkg
go/internal/gcimporter/gcimporter.go:23 unnecessary import alias exact
os/pipe_test.go:14 unnecessary import alias osexec
os/os_windows_test.go:10 unnecessary import alias osexec
Below are some of the arguably unneeded import aliases it found:
// go/internal/gcimporter/gcimporter.go
import (
"bufio"
"errors"
"fmt"
"go/build"
"go/token"
"io"
"io/ioutil"
"os"
"path/filepath"
"sort"
"strconv"
"strings"
"text/scanner"
exact "go/constant"
"go/types"
)
// os/pipe_test.go.go
import (
"fmt"
"internal/testenv"
"os"
osexec "os/exec"
"os/signal"
"syscall"
"testing"
)
TODO
- Unit tests
- Flagging of packages that contain an uppercase letter or underscore
- -w flag to write changes to file where/if possible
- Globbing support (e.g. unimport *.go)
Contributing
Pull requests welcome!