x/tools/cmd/goimports: why goimports rename variables

[airlsyn]

What version of Go are you using (go version)?

$ go version

go version go1.13.9 darwin/amd64

Does this issue reproduce with the latest release?

not tested

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/username/Library/Caches/go-build"
GOENV="/Users/username/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GONOPROXY="git.in.xxx.com"
GONOSUMDB="git.in.xxx.com"
GOOS="darwin"
GOPATH="/Users/username/go"
GOPRIVATE="git.in.xxx.com"
GOPROXY="https://goproxy.in.xxx.com,direct"
GOROOT="/usr/local/Cellar/go@1.13/1.13.9/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go@1.13/1.13.9/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/username/go/src/git.in.xxx.com/data/projectname/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/j0/j6p5rq894ysfxdscvqm4qfzh0000gn/T/go-build516394362=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

format generated thrift file

before format Output

  switch cmd {
	case "batch_get":
		if flag.NArg()-1 != 1 {
			fmt.Fprintln(os.Stderr, "BatchGet requires 1 args")
			flag.Usage()
		}
		arg8 := flag.Arg(1)
		mbTrans9 := thrift.NewTMemoryBufferLen(len(arg8))
		defer mbTrans9.Close()
		_, err10 := mbTrans9.WriteString(arg8)
		if err10 != nil {
			Usage()
			return
		}
		factory11 := thrift.NewTSimpleJSONProtocolFactory()
		jsProt12 := factory11.GetProtocol(mbTrans9)
		argvalue0 := media_profile_2_thrift.NewBatchGetParam()
		err13 := argvalue0.Read(jsProt12)
		if err13 != nil {
			Usage()
			return
		}
		value0 := argvalue0
		fmt.Print(client.BatchGet(context.Background(), value0))
		fmt.Print("\n")
		break
	case "":
		Usage()
		break
	default:
		fmt.Fprintln(os.Stderr, "Invalid function ", cmd)
	}

format with cmd

$ goimports -w -local -v -l filename

after format

after format Output

	switch cmd {
	case "batch_get":
		if flag.NArg()-1 != 1 {
			fmt.Fprintln(os.Stderr, "BatchGet requires 1 args")
			flag.Usage()
		}
		arg9 := flag.Arg(1)
		mbTrans10 := thrift.NewTMemoryBufferLen(len(arg9))
		defer mbTrans10.Close()
		_, err11 := mbTrans10.WriteString(arg9)
		if err11 != nil {
			Usage()
			return
		}
		factory12 := thrift.NewTSimpleJSONProtocolFactory()
		jsProt13 := factory12.GetProtocol(mbTrans10)
		argvalue0 := media_profile_2_thrift.NewBatchGetParam()
		err14 := argvalue0.Read(jsProt13)
		if err14 != nil {
			Usage()
			return
		}
		value0 := argvalue0
		fmt.Print(client.BatchGet(context.Background(), value0))
		fmt.Print("\n")
		break
	case "":
		Usage()
		break
	default:
		fmt.Fprintln(os.Stderr, "Invalid function ", cmd)
	}

What did you expect to see?

do not rename, just leave the variable name along

What did you see instead?

see, arg8, mbTrans9, err10, factory11, jsProt12, err13 was renamed to arg9, mbTrans10, err11, factory12, jsProt13, err14 respectively