feat: add Type alias ExitError

exec.go

@@ -7,6 +7,8 @@ import (
 	"time"
 )
 
+type ExitError = exec.ExitError
+
 // Exec represents an command executer.
 type Exec struct {
 	Signal          os.Signal

exec_test.go

@@ -3,6 +3,7 @@ package exec
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"os"
 	"os/exec"
@@ -284,3 +285,123 @@ func gentests(withSleepTest bool) []testcase {
 	}
 	return tests
 }
+
+func TestExitError(t *testing.T) {
+	t.Run("TypeIdentity", func(t *testing.T) {
+		// Test that exec.ExitError is identical to os/exec.ExitError
+		var execExitError *ExitError
+		var osExecExitError *exec.ExitError
+
+		// Type assertion should work both ways
+		_ = (*exec.ExitError)(execExitError)
+		_ = (*ExitError)(osExecExitError)
+	})
+
+	t.Run("ActualErrorCase", func(t *testing.T) {
+		// Create a command that will fail with non-zero exit code
+		var cmd *exec.Cmd
+		if runtime.GOOS == "windows" {
+			cmd = Command("cmd", "/c", "exit 1")
+		} else {
+			cmd = Command("sh", "-c", "exit 1")
+		}
+
+		err := cmd.Run()
+		if err == nil {
+			t.Fatal("Expected command to fail with exit code 1")
+		}
+
+		// Test that the error can be type asserted to exec.ExitError (our alias)
+		var exitError *ExitError
+		if !errors.As(err, &exitError) {
+			t.Fatalf("Expected error to be *exec.ExitError, got %T", err)
+		}
+
+		// Test that the error can also be type asserted to os/exec.ExitError
+		var osExitError *exec.ExitError
+		if !errors.As(err, &osExitError) {
+			t.Fatalf("Expected error to be *os/exec.ExitError, got %T", err)
+		}
+
+		// Verify ExitCode method works correctly
+		if exitError.ExitCode() != 1 {
+			t.Errorf("Expected exit code 1, got %d", exitError.ExitCode())
+		}
+
+		if osExitError.ExitCode() != 1 {
+			t.Errorf("Expected exit code 1, got %d", osExitError.ExitCode())
+		}
+
+		// Verify they are the same underlying object
+		if exitError != osExitError {
+			t.Error("Expected both type assertions to return the same object")
+		}
+	})
+
+	t.Run("ErrorMessageAndMethods", func(t *testing.T) {
+		// Test with a different exit code
+		var cmd *exec.Cmd
+		if runtime.GOOS == "windows" {
+			cmd = Command("cmd", "/c", "exit 42")
+		} else {
+			cmd = Command("sh", "-c", "exit 42")
+		}
+
+		err := cmd.Run()
+		if err == nil {
+			t.Fatal("Expected command to fail with exit code 42")
+		}
+
+		var exitError *ExitError
+		if !errors.As(err, &exitError) {
+			t.Fatalf("Expected error to be *exec.ExitError, got %T", err)
+		}
+
+		// Test ExitCode method
+		if exitError.ExitCode() != 42 {
+			t.Errorf("Expected exit code 42, got %d", exitError.ExitCode())
+		}
+
+		// Test Error method (inherited from os/exec.ExitError)
+		errorMsg := exitError.Error()
+		if errorMsg == "" {
+			t.Error("Expected non-empty error message")
+		}
+
+		// Test that ProcessState is accessible
+		if exitError.ProcessState == nil {
+			t.Error("Expected ProcessState to be non-nil")
+		}
+
+		// Test ProcessState.ExitCode() method
+		if exitError.ExitCode() != 42 {
+			t.Errorf("Expected ProcessState.ExitCode() to return 42, got %d", exitError.ExitCode())
+		}
+	})
+
+	t.Run("CommandContextWithError", func(t *testing.T) {
+		// Test with CommandContext function
+		ctx := context.Background()
+		var cmd *exec.Cmd
+		if runtime.GOOS == "windows" {
+			cmd = CommandContext(ctx, "cmd", "/c", "exit 5")
+		} else {
+			cmd = CommandContext(ctx, "sh", "-c", "exit 5")
+		}
+
+		err := cmd.Run()
+		if err == nil {
+			t.Fatal("Expected command to fail with exit code 5")
+		}
+
+		// Verify the alias works with CommandContext as well
+		var exitError *ExitError
+		if !errors.As(err, &exitError) {
+			t.Fatalf("Expected error to be *exec.ExitError, got %T", err)
+		}
+
+		if exitError.ExitCode() != 5 {
+			t.Errorf("Expected exit code 5, got %d", exitError.ExitCode())
+		}
+	})
+}