diff --git a/args_test.go b/args_test.go
new file mode 100644
index 00000000..d797b6f5
--- /dev/null
+++ b/args_test.go
@@ -0,0 +1,241 @@
+package cobra
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestNoArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: NoArgs, Run: emptyRun}
+
+	output, err := executeCommand(c)
+	if output != "" {
+		t.Errorf("Unexpected string: %v", output)
+	}
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+}
+
+func TestNoArgsWithArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: NoArgs, Run: emptyRun}
+
+	_, err := executeCommand(c, "illegal")
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := `unknown command "illegal" for "c"`
+	if got != expected {
+		t.Errorf("Expected: %q, got: %q", expected, got)
+	}
+}
+
+func TestOnlyValidArgs(t *testing.T) {
+	c := &Command{
+		Use:       "c",
+		Args:      OnlyValidArgs,
+		ValidArgs: []string{"one", "two"},
+		Run:       emptyRun,
+	}
+
+	output, err := executeCommand(c, "one", "two")
+	if output != "" {
+		t.Errorf("Unexpected output: %v", output)
+	}
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+}
+
+func TestOnlyValidArgsWithInvalidArgs(t *testing.T) {
+	c := &Command{
+		Use:       "c",
+		Args:      OnlyValidArgs,
+		ValidArgs: []string{"one", "two"},
+		Run:       emptyRun,
+	}
+
+	_, err := executeCommand(c, "three")
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := `invalid argument "three" for "c"`
+	if got != expected {
+		t.Errorf("Expected: %q, got: %q", expected, got)
+	}
+}
+
+func TestArbitraryArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: ArbitraryArgs, Run: emptyRun}
+	output, err := executeCommand(c, "a", "b")
+	if output != "" {
+		t.Errorf("Unexpected output: %v", output)
+	}
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+}
+
+func TestMinimumNArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: MinimumNArgs(2), Run: emptyRun}
+	output, err := executeCommand(c, "a", "b", "c")
+	if output != "" {
+		t.Errorf("Unexpected output: %v", output)
+	}
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+}
+
+func TestMinimumNArgsWithLessArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: MinimumNArgs(2), Run: emptyRun}
+	_, err := executeCommand(c, "a")
+
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := "requires at least 2 arg(s), only received 1"
+	if got != expected {
+		t.Fatalf("Expected %q, got %q", expected, got)
+	}
+}
+
+func TestMaximumNArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: MaximumNArgs(3), Run: emptyRun}
+	output, err := executeCommand(c, "a", "b")
+	if output != "" {
+		t.Errorf("Unexpected output: %v", output)
+	}
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+}
+
+func TestMaximumNArgsWithMoreArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: MaximumNArgs(2), Run: emptyRun}
+	_, err := executeCommand(c, "a", "b", "c")
+
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := "accepts at most 2 arg(s), received 3"
+	if got != expected {
+		t.Fatalf("Expected %q, got %q", expected, got)
+	}
+}
+
+func TestExactArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: ExactArgs(3), Run: emptyRun}
+	output, err := executeCommand(c, "a", "b", "c")
+	if output != "" {
+		t.Errorf("Unexpected output: %v", output)
+	}
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+}
+
+func TestExactArgsWithInvalidCount(t *testing.T) {
+	c := &Command{Use: "c", Args: ExactArgs(2), Run: emptyRun}
+	_, err := executeCommand(c, "a", "b", "c")
+
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := "accepts 2 arg(s), received 3"
+	if got != expected {
+		t.Fatalf("Expected %q, got %q", expected, got)
+	}
+}
+
+func TestRangeArgs(t *testing.T) {
+	c := &Command{Use: "c", Args: RangeArgs(2, 4), Run: emptyRun}
+	output, err := executeCommand(c, "a", "b", "c")
+	if output != "" {
+		t.Errorf("Unexpected output: %v", output)
+	}
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+}
+
+func TestRangeArgsWithInvalidCount(t *testing.T) {
+	c := &Command{Use: "c", Args: RangeArgs(2, 4), Run: emptyRun}
+	_, err := executeCommand(c, "a")
+
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := "accepts between 2 and 4 arg(s), received 1"
+	if got != expected {
+		t.Fatalf("Expected %q, got %q", expected, got)
+	}
+}
+
+func TestRootTakesNoArgs(t *testing.T) {
+	rootCmd := &Command{Use: "root", Run: emptyRun}
+	childCmd := &Command{Use: "child", Run: emptyRun}
+	rootCmd.AddCommand(childCmd)
+
+	_, err := executeCommand(rootCmd, "illegal", "args")
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := `unknown command "illegal" for "root"`
+	if !strings.Contains(got, expected) {
+		t.Errorf("expected %q, got %q", expected, got)
+	}
+}
+
+func TestRootTakesArgs(t *testing.T) {
+	rootCmd := &Command{Use: "root", Args: ArbitraryArgs, Run: emptyRun}
+	childCmd := &Command{Use: "child", Run: emptyRun}
+	rootCmd.AddCommand(childCmd)
+
+	_, err := executeCommand(rootCmd, "legal", "args")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+}
+
+func TestChildTakesNoArgs(t *testing.T) {
+	rootCmd := &Command{Use: "root", Run: emptyRun}
+	childCmd := &Command{Use: "child", Args: NoArgs, Run: emptyRun}
+	rootCmd.AddCommand(childCmd)
+
+	_, err := executeCommand(rootCmd, "child", "illegal", "args")
+	if err == nil {
+		t.Fatal("Expected an error")
+	}
+
+	got := err.Error()
+	expected := `unknown command "illegal" for "root child"`
+	if !strings.Contains(got, expected) {
+		t.Errorf("expected %q, got %q", expected, got)
+	}
+}
+
+func TestChildTakesArgs(t *testing.T) {
+	rootCmd := &Command{Use: "root", Run: emptyRun}
+	childCmd := &Command{Use: "child", Args: ArbitraryArgs, Run: emptyRun}
+	rootCmd.AddCommand(childCmd)
+
+	_, err := executeCommand(rootCmd, "child", "legal", "args")
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+}