Extract shell detection to its own package

Signed-off-by: David Gageot <david@gageot.net>

commands/commands.go

@@ -21,7 +21,6 @@ import (
 )
 
 var (
-	ErrUnknownShell       = errors.New("Error: Unknown shell")
 	ErrNoMachineSpecified = errors.New("Error: Expected to get one or more machine names as arguments")
 	ErrExpectedOneMachine = errors.New("Error: Expected one machine name as an argument")
 	ErrTooManyArguments   = errors.New("Error: Too many arguments given")

commands/env.go

@@ -9,6 +9,7 @@ import (
 	"text/template"
 
 	"github.com/docker/machine/commands/mcndirs"
+	"github.com/docker/machine/commands/shell"
 	"github.com/docker/machine/libmachine"
 	"github.com/docker/machine/libmachine/check"
 	"github.com/docker/machine/libmachine/log"
@@ -200,7 +201,7 @@ func getShell(userShell string) (string, error) {
 	if userShell != "" {
 		return userShell, nil
 	}
-	return detectShell()
+	return shell.Detect()
 }
 
 func findNoProxyFromEnv() (string, string) {

commands/shell/shell.go

@@ -1,14 +1,20 @@
 // +build !windows
 
-package commands
+package shell
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
 )
 
-func detectShell() (string, error) {
+var (
+	ErrUnknownShell = errors.New("Error: Unknown shell")
+)
+
+// Detect detects user's current shell.
+func Detect() (string, error) {
 	shell := os.Getenv("SHELL")
 
 	if shell == "" {

commands/shell/shell_test.go

@@ -1,4 +1,4 @@
-package commands
+package shell
 
 import (
 	"os"
@@ -11,7 +11,7 @@ func TestDetectBash(t *testing.T) {
 	originalShell := os.Getenv("SHELL")
 	os.Setenv("SHELL", "/bin/bash")
 	defer os.Setenv("SHELL", originalShell)
-	shell, err := detectShell()
+	shell, err := Detect()
 	assert.Nil(t, err)
 	assert.Equal(t, "bash", shell)
 }
@@ -23,7 +23,7 @@ func TestDetectFish(t *testing.T) {
 	originalFishdir := os.Getenv("__fish_bin_dir")
 	os.Setenv("__fish_bin_dir", "/usr/local/Cellar/fish/2.2.0/bin")
 	defer os.Setenv("__fish_bin_dir", originalFishdir)
-	shell, err := detectShell()
+	shell, err := Detect()
 	assert.Nil(t, err)
 	assert.Equal(t, "fish", shell)
 }

commands/shell/shell_unix_test.go

@@ -1,6 +1,6 @@
 // +build !windows
 
-package commands
+package shell
 
 import (
 	"fmt"
@@ -14,7 +14,7 @@ func TestUnknowShell(t *testing.T) {
 	originalShell := os.Getenv("SHELL")
 	os.Setenv("SHELL", "")
 	defer os.Setenv("SHELL", originalShell)
-	shell, err := detectShell()
+	shell, err := Detect()
 	fmt.Println(shell)
 	assert.Equal(t, err, ErrUnknownShell)
 	assert.Equal(t, "", shell)

commands/shell/shell_windows.go

@@ -1,4 +1,4 @@
-package commands
+package shell
 
 import (
 	"fmt"
@@ -50,7 +50,7 @@ func startedBy() (exefile string, err error) {
 	return name, nil
 }
 
-func detectShell() (string, error) {
+func Detect() (string, error) {
 	shell := os.Getenv("SHELL")
 
 	if shell == "" {

commands/shell/shell_windows_test.go

@@ -1,4 +1,4 @@
-package commands
+package shell
 
 import (
 	"os"
@@ -11,7 +11,7 @@ func TestDetect(t *testing.T) {
 	originalShell := os.Getenv("SHELL")
 	os.Setenv("SHELL", "")
 	defer os.Setenv("SHELL", originalShell)
-	shell, err := detectShell()
+	shell, err := Detect()
 	assert.Nil(t, err)
 	assert.Equal(t, "cmd", shell)
 }