Gci: update the way to call Run() (#1337)

Signed-off-by: Xiang Dai <long0dai@foxmail.com>

Author: daixiang0

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/Djarvur/go-err113 v0.0.0-20200511133814-5174e21577d5
 	github.com/OpenPeeDeeP/depguard v1.0.1
 	github.com/bombsimon/wsl/v3 v3.1.0
-	github.com/daixiang0/gci v0.2.2
+	github.com/daixiang0/gci v0.2.4
 	github.com/denis-tingajkin/go-header v0.3.1
 	github.com/fatih/color v1.9.0
 	github.com/go-critic/go-critic v0.5.2

go.sum

@@ -47,8 +47,8 @@ github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
-github.com/daixiang0/gci v0.2.2 h1:ql+M0OX7Z+tPt0WAMpN11rgEvZGc+dqxuw5dn6d3UJM=
-github.com/daixiang0/gci v0.2.2/go.mod h1:+AV8KmHTGxxwp/pY84TLQfFKp2vuKXXJVzF3kD/hfR4=
+github.com/daixiang0/gci v0.2.4 h1:BUCKk5nlK2m+kRIsoj+wb/5hazHvHeZieBKWd9Afa8Q=
+github.com/daixiang0/gci v0.2.4/go.mod h1:+AV8KmHTGxxwp/pY84TLQfFKp2vuKXXJVzF3kD/hfR4=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

pkg/golinters/gci.go

@@ -1,10 +1,13 @@
 package golinters
 
 import (
+	"bytes"
+	"fmt"
 	"sync"
 
 	"github.com/daixiang0/gci/pkg/gci"
 	"github.com/pkg/errors"
+	"github.com/shazow/go-diff/difflib"
 	"golang.org/x/tools/go/analysis"
 
 	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
@@ -16,6 +19,7 @@ const gciName = "gci"
 func NewGci() *goanalysis.Linter {
 	var mu sync.Mutex
 	var resIssues []goanalysis.Issue
+	differ := difflib.New()
 
 	analyzer := &analysis.Analyzer{
 		Name: gciName,
@@ -43,17 +47,28 @@ func NewGci() *goanalysis.Linter {
 			var issues []goanalysis.Issue
 
 			for _, f := range fileNames {
-				diff, err := gci.Run(f, &gci.FlagSet{LocalFlag: localFlag})
+				source, result, err := gci.Run(f, &gci.FlagSet{LocalFlag: localFlag})
 				if err != nil {
 					return nil, err
 				}
-				if diff == nil {
+				if result == nil {
 					continue
 				}
 
-				is, err := extractIssuesFromPatch(string(diff), lintCtx.Log, lintCtx, gciName)
+				diff := bytes.Buffer{}
+				_, err = diff.WriteString(fmt.Sprintf("--- %[1]s\n+++ %[1]s\n", f))
 				if err != nil {
-					return nil, errors.Wrapf(err, "can't extract issues from gci diff output %q", string(diff))
+					return nil, fmt.Errorf("can't write diff header: %v", err)
+				}
+
+				err = differ.Diff(&diff, bytes.NewReader(source), bytes.NewReader(result))
+				if err != nil {
+					return nil, fmt.Errorf("can't get gci diff output: %v", err)
+				}
+
+				is, err := extractIssuesFromPatch(diff.String(), lintCtx.Log, lintCtx, gciName)
+				if err != nil {
+					return nil, errors.Wrapf(err, "can't extract issues from gci diff output %q", diff.String())
 				}
 
 				for i := range is {

test/linters_test.go

@@ -96,7 +96,7 @@ func TestGciLocal(t *testing.T) {
 	assert.NoError(t, err)
 
 	testshared.NewLintRunner(t).RunWithYamlConfig(string(cfg), args...).
-		ExpectHasIssue("testdata/gci/gci.go:8: File is not `gci`-ed")
+		ExpectHasIssue("testdata/gci/gci.go:7: File is not `gci`-ed")
 }
 
 func saveConfig(t *testing.T, cfg map[string]interface{}) (cfgPath string, finishFunc func()) {