refactor: tmux command execution

.github/workflows/ci-cd.yml

@@ -25,6 +25,10 @@ jobs:
           go-version: "1.21"
       - name: Install deps
         run: go install github.com/jstemmer/go-junit-report/v2@latest
+      - if: startsWith(matrix.os, 'macOS')
+        run: |
+          brew update
+          brew install tmux
       - name: Run tests
         run: go test -cover -bench=. -benchmem -race -v 2>&1 ./... | go-junit-report -set-exit-code > report.xml
       - name: Test Summary

tmux/list.go

@@ -156,12 +156,12 @@ func sortSessions(sessions []*TmuxSession) []*TmuxSession {
 
 func List(o Options) ([]*TmuxSession, error) {
 	format := format()
-	output, err := tmuxCmd([]string{"list-sessions", "-F", format})
-	cleanOutput := strings.TrimSpace(output)
-	if err != nil || strings.HasPrefix(cleanOutput, "no server running on") {
-		return nil, nil
+	output, err := command.Run([]string{"list-sessions", "-F", format})
+	if err != nil {
+		return nil, err
 	}
-	sessionList := strings.TrimSpace(string(output))
+
+	sessionList := output
 	lines := strings.Split(sessionList, "\n")
 	sessions := processSessions(o, lines)
 

tmux/list_test.go

@@ -1,6 +1,7 @@
 package tmux
 
 import (
+	_ "embed"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -86,6 +87,47 @@ func TestProcessSessions(t *testing.T) {
 	}
 }
 
+//go:embed testdata/session_list.txt
+var sessionList string
+
+func TestList(t *testing.T) {
+	testCase := map[string]struct {
+		MockResponse   string
+		MockError      error
+		Options        Options
+		ExpectedLength int
+		Error          error
+	}{
+		"happy path": {
+			MockResponse:   sessionList,
+			ExpectedLength: 3,
+		},
+		"happy path show hidden": {
+			MockResponse:   sessionList,
+			Options:        Options{HideAttached: true},
+			ExpectedLength: 2,
+		},
+	}
+
+	for name, tc := range testCase {
+		t.Run(name, func(t *testing.T) {
+			command = &Command{
+				execFunc: func(string, []string) (string, error) {
+					return tc.MockResponse, tc.MockError
+				},
+			}
+			res, err := List(tc.Options)
+			require.ErrorIs(t, tc.Error, err)
+			if err != nil {
+				return
+			}
+
+			require.Len(t, res, tc.ExpectedLength)
+			t.Log(res)
+		})
+	}
+}
+
 func BenchmarkProcessSessions(b *testing.B) {
 	for n := 0; n < b.N; n++ {
 		processSessions(Options{}, []string{

tmux/testdata/session_list.txt

@@ -0,0 +1,3 @@
+1706646951  1 /dev/ttys000 1706475706 1       0 $2 1706643877 0 0 sesh /Users/test_user/dev/sesh 2,1 2
+1706632190  0  1706485534 1       0 $8 1706632189 0 0 dotfiles /Users/test_user/dotfiles 1 1
+1706485830  0  1706485825 1       0 $10 1706485825 0 0 window-name /Users/test_user/test_user/tmux-nerd-font-window-name 1 1

tmux/tmux.go

@@ -7,11 +7,82 @@ import (
 	"os"
 	"os/exec"
 	"strings"
+	"sync"
 
 	"github.com/joshmedeski/sesh/config"
 	"github.com/joshmedeski/sesh/dir"
 )
 
+var (
+	command *Command
+	once    sync.Once
+)
+
+func init() {
+	once.Do(func() {
+		var err error
+		command, err = NewCommand()
+		if err != nil {
+			log.Fatal(err)
+		}
+	})
+}
+
+type Error struct{ msg string }
+
+func (e Error) Error() string { return e.msg }
+
+var ErrNotRunning = Error{"no server running"}
+
+func executeCommand(command string, args []string) (string, error) {
+	var stdout, stderr bytes.Buffer
+	cmd := exec.Command(command, args...)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	if err := cmd.Start(); err != nil {
+		return "", err
+	}
+
+	if err := cmd.Wait(); err != nil {
+		if strings.Contains(stderr.String(), "no server running on") {
+			return "", ErrNotRunning
+		}
+
+		return "", err
+	}
+
+	out := strings.TrimSpace(stdout.String())
+	if strings.Contains(out, "no server running on") {
+		return "", ErrNotRunning
+	}
+
+	return out, nil
+}
+
+type Command struct {
+	cliPath  string
+	execFunc func(string, []string) (string, error)
+}
+
+func NewCommand() (c *Command, err error) {
+	c = new(Command)
+
+	c.cliPath, err = exec.LookPath("tmux")
+	if err != nil {
+		return nil, err
+	}
+
+	c.execFunc = executeCommand
+
+	return c, nil
+}
+
+func (c *Command) Run(args []string) (string, error) {
+	return c.execFunc(c.cliPath, args)
+}
+
 func GetSession(s string) (TmuxSession, error) {
 	sessionList, err := List(Options{})
 	if err != nil {
@@ -41,27 +112,7 @@ func GetSession(s string) (TmuxSession, error) {
 }
 
 func tmuxCmd(args []string) (string, error) {
-	tmux, err := exec.LookPath("tmux")
-	if err != nil {
-		return "", err
-	}
-	var stdout, stderr bytes.Buffer
-	cmd := exec.Command(tmux, args...)
-	cmd.Stdin = os.Stdin
-	cmd.Stdout = &stdout
-	cmd.Stderr = os.Stderr
-	cmd.Stderr = &stderr
-	if err := cmd.Start(); err != nil {
-		return "", err
-	}
-	if err := cmd.Wait(); err != nil {
-		errString := strings.TrimSpace(stderr.String())
-		if strings.HasPrefix(errString, "no server running on") {
-			return "", nil
-		}
-		return "", err
-	}
-	return stdout.String(), nil
+	return command.Run(args)
 }
 
 func isAttached() bool {