fix: detect and error out on incorrect positional args (#236)

pkg/cli/middleware/noargs.go

@@ -0,0 +1,20 @@
+package middleware
+
+import (
+	"fmt"
+
+	"github.com/urfave/cli"
+)
+
+var NoArgs cli.BeforeFunc = func(ctx *cli.Context) error {
+	// `Before` funcs get run prior to resolving subcommands from args
+	if ctx.NArg() > 0 && ctx.App.Command(ctx.Args()[0]) == nil {
+		cmdName := ctx.Command.Name
+		if cmdName == "" && ctx.App.Name != "" {
+			cmdName = ctx.App.Name
+		}
+		// Use the same error format as `cobra.NoArgs` for consistency with the old CLI.
+		return fmt.Errorf("unknown command %q for %q", ctx.Args()[0], cmdName)
+	}
+	return nil
+}