From 8c5e7e89cd394b02406afedf25aa41a23cd16570 Mon Sep 17 00:00:00 2001
From: Andrey Nering <andrey.nering@gmail.com>
Date: Sun, 12 Mar 2017 17:18:59 -0300
Subject: [PATCH] Little refactor on command creation

---
 execext/exec.go       | 22 ++++++++++++++++++++++
 execext/exec_other.go | 13 +++++++++++++
 execext/exec_win.go   | 20 ++++++++++++++++++++
 task.go               | 23 +++--------------------
 variable_handling.go  | 12 ++++--------
 5 files changed, 62 insertions(+), 28 deletions(-)
 create mode 100644 execext/exec.go
 create mode 100644 execext/exec_other.go
 create mode 100644 execext/exec_win.go

diff --git a/execext/exec.go b/execext/exec.go
new file mode 100644
index 00000000..b751da34
--- /dev/null
+++ b/execext/exec.go
@@ -0,0 +1,22 @@
+package execext
+
+import (
+	"os/exec"
+)
+
+var (
+	// ShPath is path to "sh" command
+	ShPath string
+	// ShExists is true if "sh" command is available on the system
+	ShExists bool
+)
+
+func init() {
+	var err error
+	ShPath, err = exec.LookPath("sh")
+	ShExists = err == nil
+}
+
+func newShCommand(c string) *exec.Cmd {
+	return exec.Command(ShPath, "-c", c)
+}
diff --git a/execext/exec_other.go b/execext/exec_other.go
new file mode 100644
index 00000000..e8f5410d
--- /dev/null
+++ b/execext/exec_other.go
@@ -0,0 +1,13 @@
+// +build !windows
+
+package execext
+
+import (
+	"os/exec"
+)
+
+// NewCommand returns a new command that runs on "sh" is available or on "cmd"
+// otherwise on Windows
+func NewCommand(c string) *exec.Cmd {
+	return newShCommand(c)
+}
diff --git a/execext/exec_win.go b/execext/exec_win.go
new file mode 100644
index 00000000..3054dcda
--- /dev/null
+++ b/execext/exec_win.go
@@ -0,0 +1,20 @@
+// +build windows
+
+package execext
+
+import (
+	"os/exec"
+)
+
+// NewCommand returns a new command that runs on "sh" is available or on "cmd"
+// otherwise on Windows
+func NewCommand(c string) *exec.Cmd {
+	if ShExists {
+		return newShCommand(c)
+	}
+	return newCmdCommand(c)
+}
+
+func newCmdCommand(c string) {
+	return exec.Command("cmd", "/C", c)
+}
diff --git a/task.go b/task.go
index f0c14b87..974b7472 100644
--- a/task.go
+++ b/task.go
@@ -4,19 +4,16 @@ import (
 	"fmt"
 	"log"
 	"os"
-	"os/exec"
 	"strings"
 
+	"github.com/go-task/task/execext"
+
 	"github.com/spf13/pflag"
 )
 
 var (
 	// TaskFilePath is the default Taskfile
 	TaskFilePath = "Taskfile"
-	// ShExists is true if Bash was found
-	ShExists bool
-	// ShPath constains the Bash path if found
-	ShPath string
 
 	// Force (--force or -f flag) forces a task to run even when it's up-to-date
 	Force bool
@@ -27,15 +24,6 @@ var (
 	runnedTasks = make(map[string]struct{})
 )
 
-func init() {
-	var err error
-	ShPath, err = exec.LookPath("sh")
-	if err != nil {
-		return
-	}
-	ShExists = true
-}
-
 // Task represents a task
 type Task struct {
 	Cmds      []string
@@ -142,12 +130,7 @@ func (t *Task) runCommand(i int) error {
 	if err != nil {
 		return err
 	}
-	var cmd *exec.Cmd
-	if ShExists {
-		cmd = exec.Command(ShPath, "-c", c)
-	} else {
-		cmd = exec.Command("cmd", "/C", c)
-	}
+	cmd := execext.NewCommand(c)
 	if dir != "" {
 		cmd.Dir = dir
 	}
diff --git a/variable_handling.go b/variable_handling.go
index 484c68f2..976938c6 100644
--- a/variable_handling.go
+++ b/variable_handling.go
@@ -6,11 +6,12 @@ import (
 	"errors"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"runtime"
 	"strings"
 	"text/template"
 
+	"github.com/go-task/task/execext"
+
 	"github.com/BurntSushi/toml"
 	"gopkg.in/yaml.v2"
 )
@@ -31,12 +32,7 @@ func handleDynamicVariableContent(value string) (string, error) {
 	if result, ok := varCmds[value]; ok {
 		return result, nil
 	}
-	var cmd *exec.Cmd
-	if ShExists {
-		cmd = exec.Command(ShPath, "-c", value[1:])
-	} else {
-		cmd = exec.Command("cmd", "/C", value[1:])
-	}
+	cmd := execext.NewCommand(value[1:])
 	cmd.Stdin = os.Stdin
 	cmd.Stderr = os.Stderr
 	b, err := cmd.Output()
@@ -83,7 +79,7 @@ func (t *Task) handleVariables() (map[string]string, error) {
 var templateFuncs = template.FuncMap{
 	"OS":   func() string { return runtime.GOOS },
 	"ARCH": func() string { return runtime.GOARCH },
-	"IsSH": func() bool { return ShExists },
+	"IsSH": func() bool { return execext.ShExists },
 }
 
 // ReplaceVariables writes vars into initial string