strings.Split a empty string, and len([]string) equal 1

[orange-jacky]

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

$ go version
go version go1.14 darwin/amd64

Does this issue reproduce with the latest release?

vi test.go

package main

import (
	"fmt"
	"strings"
)

func main() {
	src := ""
	slice := strings.Split(src, ",")
	fmt.Printf("src=%q slice=%+v len(slice)=%d\n", src, slice, len(slice))
}

% go run test.go
src="" slice=[] len(slice)=1

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

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN="/Users/fredlee/Documents/develop/go/workspace/bin"
GOCACHE="/Users/fredlee/Library/Caches/go-build"
GOENV="/Users/fredlee/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/fredlee/Documents/develop/go/workspace"
GOPRIVATE=""
GOPROXY="direct"
GOROOT="/usr/local/go"
GOSUMDB="off"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/fredlee/Documents/xxx/xxx/xx/xxx/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/34/z2z_vp1573g5014m8k7wys100000gn/T/go-build085642700=/tmp/go-build -gno-record-gcc-switches -fno-common"
GOROOT/bin/go version: go version go1.14 darwin/amd64
GOROOT/bin/go tool compile -V: compile version go1.14
uname -v: Darwin Kernel Version 19.0.0: Thu Oct 17 16:17:15 PDT 2019; root:xnu-6153.41.3~29/RELEASE_X86_64
ProductName:	Mac OS X
ProductVersion:	10.15.1
BuildVersion:	19B88
lldb --version: lldb-1100.0.30.6
Apple Swift version 5.1.2 (swiftlang-1100.0.278 clang-1100.0.33.9)

What did you do?

What did you expect to see?

src="" slice=[] len(slice)=0

What did you see instead?

src="" slice=[] len(slice)=1

[davecheney]

Thank you for raising this issue. Based on the documentation for strings.Split I believe this is working as intended

If s does not contain sep and sep is not empty, Split returns a slice of length 1 whose only element is s.

Based on this I am closing this issue. Please comment if you disagree but keep in mind that the operation of this function is covered by the Go 1 contract.