4 files changed, 38 insertions, 14 deletions

diff --git a/cmd/install/bash.go b/cmd/install/bash.go
index a287f99..17c64de 100644
--- a/cmd/install/bash.go
+++ b/cmd/install/bash.go
@@ -10,20 +10,25 @@ type bash struct {
 	rc string
 }
 
-func (b bash) Install(cmd, bin string) error {
+func (b bash) IsInstalled(cmd, bin string) bool {
 	completeCmd := b.cmd(cmd, bin)
-	if lineInFile(b.rc, completeCmd) {
+	return lineInFile(b.rc, completeCmd)
+}
+
+func (b bash) Install(cmd, bin string) error {
+	if b.IsInstalled(cmd, bin) {
 		return fmt.Errorf("already installed in %s", b.rc)
 	}
+	completeCmd := b.cmd(cmd, bin)
 	return appendToFile(b.rc, completeCmd)
 }
 
 func (b bash) Uninstall(cmd, bin string) error {
-	completeCmd := b.cmd(cmd, bin)
-	if !lineInFile(b.rc, completeCmd) {
+	if !b.IsInstalled(cmd, bin) {
 		return fmt.Errorf("does not installed in %s", b.rc)
 	}
 
+	completeCmd := b.cmd(cmd, bin)
 	return removeFromFile(b.rc, completeCmd)
 }
 
diff --git a/cmd/install/fish.go b/cmd/install/fish.go
index c4f2018..2b64bfc 100644
--- a/cmd/install/fish.go
+++ b/cmd/install/fish.go
@@ -14,28 +14,41 @@ type fish struct {
 	configDir string
 }
 
+func (f fish) IsInstalled(cmd, bin string) bool {
+	completionFile := f.getCompletionFilePath(cmd)
+	if _, err := os.Stat(completionFile); err == nil {
+		return true
+	}
+	return false
+}
+
 func (f fish) Install(cmd, bin string) error {
-	completionFile := filepath.Join(f.configDir, "completions", fmt.Sprintf("%s.fish", cmd))
+	if f.IsInstalled(cmd, bin) {
+		return fmt.Errorf("already installed at %s", f.getCompletionFilePath(cmd))
+	}
+
+	completionFile := f.getCompletionFilePath(cmd)
 	completeCmd, err := f.cmd(cmd, bin)
 	if err != nil {
 		return err
 	}
-	if _, err := os.Stat(completionFile); err == nil {
-		return fmt.Errorf("already installed at %s", completionFile)
-	}
 
 	return createFile(completionFile, completeCmd)
 }
 
 func (f fish) Uninstall(cmd, bin string) error {
-	completionFile := filepath.Join(f.configDir, "completions", fmt.Sprintf("%s.fish", cmd))
-	if _, err := os.Stat(completionFile); err != nil {
+	if !f.IsInstalled(cmd, bin) {
 		return fmt.Errorf("does not installed in %s", f.configDir)
 	}
 
+	completionFile := f.getCompletionFilePath(cmd)
 	return os.Remove(completionFile)
 }
 
+func (f fish) getCompletionFilePath(cmd string) string {
+	return filepath.Join(f.configDir, "completions", fmt.Sprintf("%s.fish", cmd))
+}
+
 func (f fish) cmd(cmd, bin string) (string, error) {
 	var buf bytes.Buffer
 	params := struct{ Cmd, Bin string }{cmd, bin}
diff --git a/cmd/install/install.go b/cmd/install/install.go
index 3cb9746..a9a01d4 100644
--- a/cmd/install/install.go
+++ b/cmd/install/install.go
@@ -11,6 +11,7 @@ import (
 )
 
 type installer interface {
+	IsInstalled(cmd, bin string) bool
 	Install(cmd, bin string) error
 	Uninstall(cmd, bin string) error
 }
diff --git a/cmd/install/zsh.go b/cmd/install/zsh.go
index a625f53..29950ab 100644
--- a/cmd/install/zsh.go
+++ b/cmd/install/zsh.go
@@ -11,12 +11,17 @@ type zsh struct {
 	rc string
 }
 
-func (z zsh) Install(cmd, bin string) error {
+func (z zsh) IsInstalled(cmd, bin string) bool {
 	completeCmd := z.cmd(cmd, bin)
-	if lineInFile(z.rc, completeCmd) {
+	return lineInFile(z.rc, completeCmd)
+}
+
+func (z zsh) Install(cmd, bin string) error {
+	if z.IsInstalled(cmd, bin) {
 		return fmt.Errorf("already installed in %s", z.rc)
 	}
 
+	completeCmd := z.cmd(cmd, bin)
 	bashCompInit := "autoload -U +X bashcompinit && bashcompinit"
 	if !lineInFile(z.rc, bashCompInit) {
 		completeCmd = bashCompInit + "\n" + completeCmd
@@ -26,11 +31,11 @@ func (z zsh) Install(cmd, bin string) error {
 }
 
 func (z zsh) Uninstall(cmd, bin string) error {
-	completeCmd := z.cmd(cmd, bin)
-	if !lineInFile(z.rc, completeCmd) {
+	if !z.IsInstalled(cmd, bin) {
 		return fmt.Errorf("does not installed in %s", z.rc)
 	}
 
+	completeCmd := z.cmd(cmd, bin)
 	return removeFromFile(z.rc, completeCmd)
 }