Fix #263: update goimports

The new version of goimports works 100x faster
with go modules. Also it has some new features:

$ git cherry -v 6c7e314b6563 92cdcd90bf52 | fgrep imports
+ 5bbcdc15656ef390fab5dd6e8daf95354f7171e3 imports: redesign fixImports
+ ee45598d2ff288037f53f9e13ae0b1a6e2165ad5 imports: create named imports for name/path mismatches (again)
+ 4c53570e0460bc32468f75bf9dd71c018d03bfa9 imports: ignore globals in different packages
+ 1d424dbce8dd500e9e449fd3ff9d0668c09e2ae1 imports: clean up customization seam
+ 6a3e9aa2ab7749d72d1006ee484271b4a11f96c2 imports: fix renamed sibling imports
+ 5f4a60f04f23ac48e0665f257413ae3eacf339be imports: fix renamed sibling imports more
+ bbccd8cae4a9a47e0f978e03ff4b5df88a9fde1e imports: use go/packages, support modules
+ d4971274fe382404aee0e8c163af974f2bf738e6 imports: don't remove imports that conflict with globals

go.mod

@@ -24,7 +24,7 @@ require (
 	github.com/golangci/go-tools v0.0.0-20180902103155-93eecd106a0b
 	github.com/golangci/goconst v0.0.0-20180610141641-041c5f2b40f3
 	github.com/golangci/gocyclo v0.0.0-20180528134321-2becd97e67ee
-	github.com/golangci/gofmt v0.0.0-20181105071733-f021c4179c82
+	github.com/golangci/gofmt v0.0.0-20181105071733-0b8337e80d98
 	github.com/golangci/gosec v0.0.0-20180901114220-8afd9cbb6cfb
 	github.com/golangci/govet v0.0.0-20180818181408-44ddbe260190
 	github.com/golangci/ineffassign v0.0.0-20180808204949-2ee8f2867dde

go.sum

@@ -55,8 +55,8 @@ github.com/golangci/goconst v0.0.0-20180610141641-041c5f2b40f3 h1:pe9JHs3cHHDQgO
 github.com/golangci/goconst v0.0.0-20180610141641-041c5f2b40f3/go.mod h1:JXrF4TWy4tXYn62/9x8Wm/K/dm06p8tCKwFRDPZG/1o=
 github.com/golangci/gocyclo v0.0.0-20180528134321-2becd97e67ee h1:J2XAy40+7yz70uaOiMbNnluTg7gyQhtGqLQncQh+4J8=
 github.com/golangci/gocyclo v0.0.0-20180528134321-2becd97e67ee/go.mod h1:ozx7R9SIwqmqf5pRP90DhR2Oay2UIjGuKheCBCNwAYU=
-github.com/golangci/gofmt v0.0.0-20181105071733-f021c4179c82 h1:GzPqZCXdBR/5zaqMWNsxRk60z16CaQjyytNTFpei3bw=
-github.com/golangci/gofmt v0.0.0-20181105071733-f021c4179c82/go.mod h1:9qCChq59u/eW8im404Q2WWTrnBUQKjpNYKMbU4M7EFU=
+github.com/golangci/gofmt v0.0.0-20181105071733-0b8337e80d98 h1:ir6/L2ZOJfFrJlOTsuf/hlzdPuUwXV/VzkSlgS6f1vs=
+github.com/golangci/gofmt v0.0.0-20181105071733-0b8337e80d98/go.mod h1:9qCChq59u/eW8im404Q2WWTrnBUQKjpNYKMbU4M7EFU=
 github.com/golangci/gosec v0.0.0-20180901114220-8afd9cbb6cfb h1:Bi7BYmZVg4C+mKGi8LeohcP2GGUl2XJD4xCkJoZSaYc=
 github.com/golangci/gosec v0.0.0-20180901114220-8afd9cbb6cfb/go.mod h1:ON/c2UR0VAAv6ZEAFKhjCLplESSmRFfZcDLASbI1GWo=
 github.com/golangci/govet v0.0.0-20180818181408-44ddbe260190 h1:SLIgprnxQNjBpkz55PK1vfb64/gKU/TgVi0obFw8Lec=

pkg/config/reader.go

@@ -12,7 +12,7 @@ import (
 	"github.com/golangci/golangci-lint/pkg/fsutils"
 	"github.com/golangci/golangci-lint/pkg/logutils"
 
-	"github.com/mitchellh/go-homedir"
+	homedir "github.com/mitchellh/go-homedir"
 )
 
 type FileReader struct {

pkg/golinters/gofmt.go

@@ -6,10 +6,9 @@ import (
 	"fmt"
 	"go/token"
 
-	"github.com/golangci/tools/imports" // TODO: replace with x/tools when use it in golangci/gofmt/gofmt
-
 	gofmtAPI "github.com/golangci/gofmt/gofmt"
 	goimportsAPI "github.com/golangci/gofmt/goimports"
+	"golang.org/x/tools/imports"
 	"sourcegraph.com/sourcegraph/go-diff/diff"
 
 	"github.com/golangci/golangci-lint/pkg/lint/linter"

test/linters_test.go

@@ -15,7 +15,7 @@ import (
 
 	assert "github.com/stretchr/testify/require"
 
-	"gopkg.in/yaml.v2"
+	yaml "gopkg.in/yaml.v2"
 )
 
 func runGoErrchk(c *exec.Cmd, t *testing.T) {

vendor/github.com/golangci/gofmt/goimports/goimports.go

@@ -21,7 +21,7 @@ import (
 	"runtime/pprof"
 	"strings"
 
-	"github.com/golangci/tools/imports"
+	"golang.org/x/tools/imports"
 )
 
 var (

vendor/github.com/golangci/gofmt/goimports/golangci.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 
-	"github.com/golangci/tools/imports"
+	"golang.org/x/tools/imports"
 )
 
 func Run(filename string) ([]byte, error) {

vendor/golang.org/x/tools/imports/imports.go

@@ -0,0 +1,309 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate go run mkstdlib.go
+
+// Package imports implements a Go pretty-printer (like package "go/format")
+// that also adds or removes import statements as necessary.
+package imports // import "golang.org/x/tools/imports"
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"io"
+	"io/ioutil"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"golang.org/x/tools/go/ast/astutil"
+)
+
+// Options specifies options for processing files.
+type Options struct {
+	Fragment  bool // Accept fragment of a source file (no package statement)
+	AllErrors bool // Report all errors (not just the first 10 on different lines)
+
+	Comments  bool // Print comments (true if nil *Options provided)
+	TabIndent bool // Use tabs for indent (true if nil *Options provided)
+	TabWidth  int  // Tab width (8 if nil *Options provided)
+
+	FormatOnly bool // Disable the insertion and deletion of imports
+}
+
+// Process formats and adjusts imports for the provided file.
+// If opt is nil the defaults are used.
+//
+// Note that filename's directory influences which imports can be chosen,
+// so it is important that filename be accurate.
+// To process data ``as if'' it were in filename, pass the data as a non-nil src.
+func Process(filename string, src []byte, opt *Options) ([]byte, error) {
+	if opt == nil {
+		opt = &Options{Comments: true, TabIndent: true, TabWidth: 8}
+	}
+	if src == nil {
+		b, err := ioutil.ReadFile(filename)
+		if err != nil {
+			return nil, err
+		}
+		src = b
+	}
+
+	fileSet := token.NewFileSet()
+	file, adjust, err := parse(fileSet, filename, src, opt)
+	if err != nil {
+		return nil, err
+	}
+
+	if !opt.FormatOnly {
+		if err := fixImports(fileSet, file, filename); err != nil {
+			return nil, err
+		}
+	}
+
+	sortImports(fileSet, file)
+	imps := astutil.Imports(fileSet, file)
+	var spacesBefore []string // import paths we need spaces before
+	for _, impSection := range imps {
+		// Within each block of contiguous imports, see if any
+		// import lines are in different group numbers. If so,
+		// we'll need to put a space between them so it's
+		// compatible with gofmt.
+		lastGroup := -1
+		for _, importSpec := range impSection {
+			importPath, _ := strconv.Unquote(importSpec.Path.Value)
+			groupNum := importGroup(importPath)
+			if groupNum != lastGroup && lastGroup != -1 {
+				spacesBefore = append(spacesBefore, importPath)
+			}
+			lastGroup = groupNum
+		}
+
+	}
+
+	printerMode := printer.UseSpaces
+	if opt.TabIndent {
+		printerMode |= printer.TabIndent
+	}
+	printConfig := &printer.Config{Mode: printerMode, Tabwidth: opt.TabWidth}
+
+	var buf bytes.Buffer
+	err = printConfig.Fprint(&buf, fileSet, file)
+	if err != nil {
+		return nil, err
+	}
+	out := buf.Bytes()
+	if adjust != nil {
+		out = adjust(src, out)
+	}
+	if len(spacesBefore) > 0 {
+		out, err = addImportSpaces(bytes.NewReader(out), spacesBefore)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	out, err = format.Source(out)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// parse parses src, which was read from filename,
+// as a Go source file or statement list.
+func parse(fset *token.FileSet, filename string, src []byte, opt *Options) (*ast.File, func(orig, src []byte) []byte, error) {
+	parserMode := parser.Mode(0)
+	if opt.Comments {
+		parserMode |= parser.ParseComments
+	}
+	if opt.AllErrors {
+		parserMode |= parser.AllErrors
+	}
+
+	// Try as whole source file.
+	file, err := parser.ParseFile(fset, filename, src, parserMode)
+	if err == nil {
+		return file, nil, nil
+	}
+	// If the error is that the source file didn't begin with a
+	// package line and we accept fragmented input, fall through to
+	// try as a source fragment.  Stop and return on any other error.
+	if !opt.Fragment || !strings.Contains(err.Error(), "expected 'package'") {
+		return nil, nil, err
+	}
+
+	// If this is a declaration list, make it a source file
+	// by inserting a package clause.
+	// Insert using a ;, not a newline, so that parse errors are on
+	// the correct line.
+	const prefix = "package main;"
+	psrc := append([]byte(prefix), src...)
+	file, err = parser.ParseFile(fset, filename, psrc, parserMode)
+	if err == nil {
+		// Gofmt will turn the ; into a \n.
+		// Do that ourselves now and update the file contents,
+		// so that positions and line numbers are correct going forward.
+		psrc[len(prefix)-1] = '\n'
+		fset.File(file.Package).SetLinesForContent(psrc)
+
+		// If a main function exists, we will assume this is a main
+		// package and leave the file.
+		if containsMainFunc(file) {
+			return file, nil, nil
+		}
+
+		adjust := func(orig, src []byte) []byte {
+			// Remove the package clause.
+			src = src[len(prefix):]
+			return matchSpace(orig, src)
+		}
+		return file, adjust, nil
+	}
+	// If the error is that the source file didn't begin with a
+	// declaration, fall through to try as a statement list.
+	// Stop and return on any other error.
+	if !strings.Contains(err.Error(), "expected declaration") {
+		return nil, nil, err
+	}
+
+	// If this is a statement list, make it a source file
+	// by inserting a package clause and turning the list
+	// into a function body.  This handles expressions too.
+	// Insert using a ;, not a newline, so that the line numbers
+	// in fsrc match the ones in src.
+	fsrc := append(append([]byte("package p; func _() {"), src...), '}')
+	file, err = parser.ParseFile(fset, filename, fsrc, parserMode)
+	if err == nil {
+		adjust := func(orig, src []byte) []byte {
+			// Remove the wrapping.
+			// Gofmt has turned the ; into a \n\n.
+			src = src[len("package p\n\nfunc _() {"):]
+			src = src[:len(src)-len("}\n")]
+			// Gofmt has also indented the function body one level.
+			// Remove that indent.
+			src = bytes.Replace(src, []byte("\n\t"), []byte("\n"), -1)
+			return matchSpace(orig, src)
+		}
+		return file, adjust, nil
+	}
+
+	// Failed, and out of options.
+	return nil, nil, err
+}
+
+// containsMainFunc checks if a file contains a function declaration with the
+// function signature 'func main()'
+func containsMainFunc(file *ast.File) bool {
+	for _, decl := range file.Decls {
+		if f, ok := decl.(*ast.FuncDecl); ok {
+			if f.Name.Name != "main" {
+				continue
+			}
+
+			if len(f.Type.Params.List) != 0 {
+				continue
+			}
+
+			if f.Type.Results != nil && len(f.Type.Results.List) != 0 {
+				continue
+			}
+
+			return true
+		}
+	}
+
+	return false
+}
+
+func cutSpace(b []byte) (before, middle, after []byte) {
+	i := 0
+	for i < len(b) && (b[i] == ' ' || b[i] == '\t' || b[i] == '\n') {
+		i++
+	}
+	j := len(b)
+	for j > 0 && (b[j-1] == ' ' || b[j-1] == '\t' || b[j-1] == '\n') {
+		j--
+	}
+	if i <= j {
+		return b[:i], b[i:j], b[j:]
+	}
+	return nil, nil, b[j:]
+}
+
+// matchSpace reformats src to use the same space context as orig.
+// 1) If orig begins with blank lines, matchSpace inserts them at the beginning of src.
+// 2) matchSpace copies the indentation of the first non-blank line in orig
+//    to every non-blank line in src.
+// 3) matchSpace copies the trailing space from orig and uses it in place
+//   of src's trailing space.
+func matchSpace(orig []byte, src []byte) []byte {
+	before, _, after := cutSpace(orig)
+	i := bytes.LastIndex(before, []byte{'\n'})
+	before, indent := before[:i+1], before[i+1:]
+
+	_, src, _ = cutSpace(src)
+
+	var b bytes.Buffer
+	b.Write(before)
+	for len(src) > 0 {
+		line := src
+		if i := bytes.IndexByte(line, '\n'); i >= 0 {
+			line, src = line[:i+1], line[i+1:]
+		} else {
+			src = nil
+		}
+		if len(line) > 0 && line[0] != '\n' { // not blank
+			b.Write(indent)
+		}
+		b.Write(line)
+	}
+	b.Write(after)
+	return b.Bytes()
+}
+
+var impLine = regexp.MustCompile(`^\s+(?:[\w\.]+\s+)?"(.+)"`)
+
+func addImportSpaces(r io.Reader, breaks []string) ([]byte, error) {
+	var out bytes.Buffer
+	in := bufio.NewReader(r)
+	inImports := false
+	done := false
+	for {
+		s, err := in.ReadString('\n')
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return nil, err
+		}
+
+		if !inImports && !done && strings.HasPrefix(s, "import") {
+			inImports = true
+		}
+		if inImports && (strings.HasPrefix(s, "var") ||
+			strings.HasPrefix(s, "func") ||
+			strings.HasPrefix(s, "const") ||
+			strings.HasPrefix(s, "type")) {
+			done = true
+			inImports = false
+		}
+		if inImports && len(breaks) > 0 {
+			if m := impLine.FindStringSubmatch(s); m != nil {
+				if m[1] == breaks[0] {
+					out.WriteByte('\n')
+					breaks = breaks[1:]
+				}
+			}
+		}
+
+		fmt.Fprint(&out, s)
+	}
+	return out.Bytes(), nil
+}

vendor/golang.org/x/tools/imports/mkindex.go

@@ -0,0 +1,173 @@
+// +build ignore
+
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Command mkindex creates the file "pkgindex.go" containing an index of the Go
+// standard library. The file is intended to be built as part of the imports
+// package, so that the package may be used in environments where a GOROOT is
+// not available (such as App Engine).
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+var (
+	pkgIndex = make(map[string][]pkg)
+	exports  = make(map[string]map[string]bool)
+)
+
+func main() {
+	// Don't use GOPATH.
+	ctx := build.Default
+	ctx.GOPATH = ""
+
+	// Populate pkgIndex global from GOROOT.
+	for _, path := range ctx.SrcDirs() {
+		f, err := os.Open(path)
+		if err != nil {
+			log.Print(err)
+			continue
+		}
+		children, err := f.Readdir(-1)
+		f.Close()
+		if err != nil {
+			log.Print(err)
+			continue
+		}
+		for _, child := range children {
+			if child.IsDir() {
+				loadPkg(path, child.Name())
+			}
+		}
+	}
+	// Populate exports global.
+	for _, ps := range pkgIndex {
+		for _, p := range ps {
+			e := loadExports(p.dir)
+			if e != nil {
+				exports[p.dir] = e
+			}
+		}
+	}
+
+	// Construct source file.
+	var buf bytes.Buffer
+	fmt.Fprint(&buf, pkgIndexHead)
+	fmt.Fprintf(&buf, "var pkgIndexMaster = %#v\n", pkgIndex)
+	fmt.Fprintf(&buf, "var exportsMaster = %#v\n", exports)
+	src := buf.Bytes()
+
+	// Replace main.pkg type name with pkg.
+	src = bytes.Replace(src, []byte("main.pkg"), []byte("pkg"), -1)
+	// Replace actual GOROOT with "/go".
+	src = bytes.Replace(src, []byte(ctx.GOROOT), []byte("/go"), -1)
+	// Add some line wrapping.
+	src = bytes.Replace(src, []byte("}, "), []byte("},\n"), -1)
+	src = bytes.Replace(src, []byte("true, "), []byte("true,\n"), -1)
+
+	var err error
+	src, err = format.Source(src)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Write out source file.
+	err = ioutil.WriteFile("pkgindex.go", src, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+const pkgIndexHead = `package imports
+
+func init() {
+	pkgIndexOnce.Do(func() {
+		pkgIndex.m = pkgIndexMaster
+	})
+	loadExports = func(dir string) map[string]bool {
+		return exportsMaster[dir]
+	}
+}
+`
+
+type pkg struct {
+	importpath string // full pkg import path, e.g. "net/http"
+	dir        string // absolute file path to pkg directory e.g. "/usr/lib/go/src/fmt"
+}
+
+var fset = token.NewFileSet()
+
+func loadPkg(root, importpath string) {
+	shortName := path.Base(importpath)
+	if shortName == "testdata" {
+		return
+	}
+
+	dir := filepath.Join(root, importpath)
+	pkgIndex[shortName] = append(pkgIndex[shortName], pkg{
+		importpath: importpath,
+		dir:        dir,
+	})
+
+	pkgDir, err := os.Open(dir)
+	if err != nil {
+		return
+	}
+	children, err := pkgDir.Readdir(-1)
+	pkgDir.Close()
+	if err != nil {
+		return
+	}
+	for _, child := range children {
+		name := child.Name()
+		if name == "" {
+			continue
+		}
+		if c := name[0]; c == '.' || ('0' <= c && c <= '9') {
+			continue
+		}
+		if child.IsDir() {
+			loadPkg(root, filepath.Join(importpath, name))
+		}
+	}
+}
+
+func loadExports(dir string) map[string]bool {
+	exports := make(map[string]bool)
+	buildPkg, err := build.ImportDir(dir, 0)
+	if err != nil {
+		if strings.Contains(err.Error(), "no buildable Go source files in") {
+			return nil
+		}
+		log.Printf("could not import %q: %v", dir, err)
+		return nil
+	}
+	for _, file := range buildPkg.GoFiles {
+		f, err := parser.ParseFile(fset, filepath.Join(dir, file), nil, 0)
+		if err != nil {
+			log.Printf("could not parse %q: %v", file, err)
+			continue
+		}
+		for name := range f.Scope.Objects {
+			if ast.IsExported(name) {
+				exports[name] = true
+			}
+		}
+	}
+	return exports
+}

vendor/golang.org/x/tools/imports/mkstdlib.go

@@ -0,0 +1,111 @@
+// +build ignore
+
+// mkstdlib generates the zstdlib.go file, containing the Go standard
+// library API symbols. It's baked into the binary to avoid scanning
+// GOPATH in the common case.
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"go/format"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"sort"
+	"strings"
+)
+
+func mustOpen(name string) io.Reader {
+	f, err := os.Open(name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return f
+}
+
+func api(base string) string {
+	return filepath.Join(runtime.GOROOT(), "api", base)
+}
+
+var sym = regexp.MustCompile(`^pkg (\S+).*?, (?:var|func|type|const) ([A-Z]\w*)`)
+
+var unsafeSyms = map[string]bool{"Alignof": true, "ArbitraryType": true, "Offsetof": true, "Pointer": true, "Sizeof": true}
+
+func main() {
+	var buf bytes.Buffer
+	outf := func(format string, args ...interface{}) {
+		fmt.Fprintf(&buf, format, args...)
+	}
+	outf("// Code generated by mkstdlib.go. DO NOT EDIT.\n\n")
+	outf("package imports\n")
+	outf("var stdlib = map[string]map[string]bool{\n")
+	f := io.MultiReader(
+		mustOpen(api("go1.txt")),
+		mustOpen(api("go1.1.txt")),
+		mustOpen(api("go1.2.txt")),
+		mustOpen(api("go1.3.txt")),
+		mustOpen(api("go1.4.txt")),
+		mustOpen(api("go1.5.txt")),
+		mustOpen(api("go1.6.txt")),
+		mustOpen(api("go1.7.txt")),
+		mustOpen(api("go1.8.txt")),
+		mustOpen(api("go1.9.txt")),
+		mustOpen(api("go1.10.txt")),
+		mustOpen(api("go1.11.txt")),
+	)
+	sc := bufio.NewScanner(f)
+
+	pkgs := map[string]map[string]bool{
+		"unsafe": unsafeSyms,
+	}
+	paths := []string{"unsafe"}
+
+	for sc.Scan() {
+		l := sc.Text()
+		has := func(v string) bool { return strings.Contains(l, v) }
+		if has("struct, ") || has("interface, ") || has(", method (") {
+			continue
+		}
+		if m := sym.FindStringSubmatch(l); m != nil {
+			path, sym := m[1], m[2]
+
+			if _, ok := pkgs[path]; !ok {
+				pkgs[path] = map[string]bool{}
+				paths = append(paths, path)
+			}
+			pkgs[path][sym] = true
+		}
+	}
+	if err := sc.Err(); err != nil {
+		log.Fatal(err)
+	}
+	sort.Strings(paths)
+	for _, path := range paths {
+		outf("\t%q: map[string]bool{\n", path)
+		pkg := pkgs[path]
+		var syms []string
+		for sym := range pkg {
+			syms = append(syms, sym)
+		}
+		sort.Strings(syms)
+		for _, sym := range syms {
+			outf("\t\t%q: true,\n", sym)
+		}
+		outf("},\n")
+	}
+	outf("}\n")
+	fmtbuf, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+	err = ioutil.WriteFile("zstdlib.go", fmtbuf, 0666)
+	if err != nil {
+		log.Fatal(err)
+	}
+}

vendor/golang.org/x/tools/imports/sortimports.go

@@ -0,0 +1,230 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Hacked up copy of go/ast/import.go
+
+package imports
+
+import (
+	"go/ast"
+	"go/token"
+	"sort"
+	"strconv"
+)
+
+// sortImports sorts runs of consecutive import lines in import blocks in f.
+// It also removes duplicate imports when it is possible to do so without data loss.
+func sortImports(fset *token.FileSet, f *ast.File) {
+	for i, d := range f.Decls {
+		d, ok := d.(*ast.GenDecl)
+		if !ok || d.Tok != token.IMPORT {
+			// Not an import declaration, so we're done.
+			// Imports are always first.
+			break
+		}
+
+		if len(d.Specs) == 0 {
+			// Empty import block, remove it.
+			f.Decls = append(f.Decls[:i], f.Decls[i+1:]...)
+		}
+
+		if !d.Lparen.IsValid() {
+			// Not a block: sorted by default.
+			continue
+		}
+
+		// Identify and sort runs of specs on successive lines.
+		i := 0
+		specs := d.Specs[:0]
+		for j, s := range d.Specs {
+			if j > i && fset.Position(s.Pos()).Line > 1+fset.Position(d.Specs[j-1].End()).Line {
+				// j begins a new run.  End this one.
+				specs = append(specs, sortSpecs(fset, f, d.Specs[i:j])...)
+				i = j
+			}
+		}
+		specs = append(specs, sortSpecs(fset, f, d.Specs[i:])...)
+		d.Specs = specs
+
+		// Deduping can leave a blank line before the rparen; clean that up.
+		if len(d.Specs) > 0 {
+			lastSpec := d.Specs[len(d.Specs)-1]
+			lastLine := fset.Position(lastSpec.Pos()).Line
+			if rParenLine := fset.Position(d.Rparen).Line; rParenLine > lastLine+1 {
+				fset.File(d.Rparen).MergeLine(rParenLine - 1)
+			}
+		}
+	}
+}
+
+func importPath(s ast.Spec) string {
+	t, err := strconv.Unquote(s.(*ast.ImportSpec).Path.Value)
+	if err == nil {
+		return t
+	}
+	return ""
+}
+
+func importName(s ast.Spec) string {
+	n := s.(*ast.ImportSpec).Name
+	if n == nil {
+		return ""
+	}
+	return n.Name
+}
+
+func importComment(s ast.Spec) string {
+	c := s.(*ast.ImportSpec).Comment
+	if c == nil {
+		return ""
+	}
+	return c.Text()
+}
+
+// collapse indicates whether prev may be removed, leaving only next.
+func collapse(prev, next ast.Spec) bool {
+	if importPath(next) != importPath(prev) || importName(next) != importName(prev) {
+		return false
+	}
+	return prev.(*ast.ImportSpec).Comment == nil
+}
+
+type posSpan struct {
+	Start token.Pos
+	End   token.Pos
+}
+
+func sortSpecs(fset *token.FileSet, f *ast.File, specs []ast.Spec) []ast.Spec {
+	// Can't short-circuit here even if specs are already sorted,
+	// since they might yet need deduplication.
+	// A lone import, however, may be safely ignored.
+	if len(specs) <= 1 {
+		return specs
+	}
+
+	// Record positions for specs.
+	pos := make([]posSpan, len(specs))
+	for i, s := range specs {
+		pos[i] = posSpan{s.Pos(), s.End()}
+	}
+
+	// Identify comments in this range.
+	// Any comment from pos[0].Start to the final line counts.
+	lastLine := fset.Position(pos[len(pos)-1].End).Line
+	cstart := len(f.Comments)
+	cend := len(f.Comments)
+	for i, g := range f.Comments {
+		if g.Pos() < pos[0].Start {
+			continue
+		}
+		if i < cstart {
+			cstart = i
+		}
+		if fset.Position(g.End()).Line > lastLine {
+			cend = i
+			break
+		}
+	}
+	comments := f.Comments[cstart:cend]
+
+	// Assign each comment to the import spec preceding it.
+	importComment := map[*ast.ImportSpec][]*ast.CommentGroup{}
+	specIndex := 0
+	for _, g := range comments {
+		for specIndex+1 < len(specs) && pos[specIndex+1].Start <= g.Pos() {
+			specIndex++
+		}
+		s := specs[specIndex].(*ast.ImportSpec)
+		importComment[s] = append(importComment[s], g)
+	}
+
+	// Sort the import specs by import path.
+	// Remove duplicates, when possible without data loss.
+	// Reassign the import paths to have the same position sequence.
+	// Reassign each comment to abut the end of its spec.
+	// Sort the comments by new position.
+	sort.Sort(byImportSpec(specs))
+
+	// Dedup. Thanks to our sorting, we can just consider
+	// adjacent pairs of imports.
+	deduped := specs[:0]
+	for i, s := range specs {
+		if i == len(specs)-1 || !collapse(s, specs[i+1]) {
+			deduped = append(deduped, s)
+		} else {
+			p := s.Pos()
+			fset.File(p).MergeLine(fset.Position(p).Line)
+		}
+	}
+	specs = deduped
+
+	// Fix up comment positions
+	for i, s := range specs {
+		s := s.(*ast.ImportSpec)
+		if s.Name != nil {
+			s.Name.NamePos = pos[i].Start
+		}
+		s.Path.ValuePos = pos[i].Start
+		s.EndPos = pos[i].End
+		nextSpecPos := pos[i].End
+
+		for _, g := range importComment[s] {
+			for _, c := range g.List {
+				c.Slash = pos[i].End
+				nextSpecPos = c.End()
+			}
+		}
+		if i < len(specs)-1 {
+			pos[i+1].Start = nextSpecPos
+			pos[i+1].End = nextSpecPos
+		}
+	}
+
+	sort.Sort(byCommentPos(comments))
+
+	// Fixup comments can insert blank lines, because import specs are on different lines.
+	// We remove those blank lines here by merging import spec to the first import spec line.
+	firstSpecLine := fset.Position(specs[0].Pos()).Line
+	for _, s := range specs[1:] {
+		p := s.Pos()
+		line := fset.File(p).Line(p)
+		for previousLine := line - 1; previousLine >= firstSpecLine; {
+			fset.File(p).MergeLine(previousLine)
+			previousLine--
+		}
+	}
+	return specs
+}
+
+type byImportSpec []ast.Spec // slice of *ast.ImportSpec
+
+func (x byImportSpec) Len() int      { return len(x) }
+func (x byImportSpec) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+func (x byImportSpec) Less(i, j int) bool {
+	ipath := importPath(x[i])
+	jpath := importPath(x[j])
+
+	igroup := importGroup(ipath)
+	jgroup := importGroup(jpath)
+	if igroup != jgroup {
+		return igroup < jgroup
+	}
+
+	if ipath != jpath {
+		return ipath < jpath
+	}
+	iname := importName(x[i])
+	jname := importName(x[j])
+
+	if iname != jname {
+		return iname < jname
+	}
+	return importComment(x[i]) < importComment(x[j])
+}
+
+type byCommentPos []*ast.CommentGroup
+
+func (x byCommentPos) Len() int           { return len(x) }
+func (x byCommentPos) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+func (x byCommentPos) Less(i, j int) bool { return x[i].Pos() < x[j].Pos() }

vendor/modules.txt

@@ -75,7 +75,7 @@ github.com/golangci/go-tools/staticcheck/vrp
 github.com/golangci/goconst
 # github.com/golangci/gocyclo v0.0.0-20180528134321-2becd97e67ee
 github.com/golangci/gocyclo/pkg/gocyclo
-# github.com/golangci/gofmt v0.0.0-20181105071733-f021c4179c82
+# github.com/golangci/gofmt v0.0.0-20181105071733-0b8337e80d98
 github.com/golangci/gofmt/gofmt
 github.com/golangci/gofmt/goimports
 # github.com/golangci/gosec v0.0.0-20180901114220-8afd9cbb6cfb
@@ -202,6 +202,7 @@ golang.org/x/tools/go/loader
 golang.org/x/tools/go/packages
 golang.org/x/tools/go/ast/astutil
 golang.org/x/tools/go/types/typeutil
+golang.org/x/tools/imports
 golang.org/x/tools/go/gcexportdata
 golang.org/x/tools/go/buildutil
 golang.org/x/tools/go/internal/cgo