Merge pull request mistifyio#90 from corhere/cmderror-args

Properly substitute command path in `Run()` error

utils.go

@@ -37,13 +37,16 @@ func (c *command) Run(arg ...string) ([][]string, error) {
 	cmd.Stderr = &stderr
 
 	id := uuid.New().String()
-	joinedArgs := strings.Join(cmd.Args, " ")
+	joinedArgs := cmd.Path
+	if len(cmd.Args) > 1 {
+		joinedArgs = strings.Join(append([]string{cmd.Path}, cmd.Args[1:]...), " ")
+	}
 
 	logger.Log([]string{"ID:" + id, "START", joinedArgs})
 	if err := cmd.Run(); err != nil {
 		return nil, &Error{
 			Err:    err,
-			Debug:  strings.Join([]string{cmd.Path, joinedArgs[1:]}, " "),
+			Debug:  joinedArgs,
 			Stderr: stderr.String(),
 		}
 	}

utils_test.go

@@ -1,6 +1,8 @@
 package zfs
 
 import (
+	"errors"
+	"os/exec"
 	"reflect"
 	"testing"
 )
@@ -36,3 +38,34 @@ func TestParseLine(t *testing.T) {
 		})
 	}
 }
+
+func TestCommandError(t *testing.T) {
+	cmd := &command{Command: "false"}
+	expectedPath, err := exec.LookPath(cmd.Command)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, tt := range []struct {
+		name          string
+		args          []string
+		expectedDebug string
+	}{
+		{name: "NoArgs", expectedDebug: expectedPath},
+		{name: "WithArgs", args: []string{"foo"}, expectedDebug: expectedPath + " foo"},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := cmd.Run(tt.args...)
+			if err == nil {
+				t.Fatal("command.Run: wanted error, got nil")
+			}
+			var e *Error
+			if !errors.As(err, &e) {
+				t.Fatalf("command.Run (error): wanted *Error, got %T (%[1]v)", err)
+			}
+			if e.Debug != tt.expectedDebug {
+				t.Fatalf("command.Run (error): wanted Debug %q, got %q", tt.expectedDebug, e.Debug)
+			}
+		})
+	}
+}