cli: error out on unknown command

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

tests/common.go

@@ -0,0 +1,29 @@
+package tests
+
+import (
+	"testing"
+
+	"github.com/moby/buildkit/util/testutil/integration"
+	"github.com/stretchr/testify/require"
+)
+
+var commonTests = []func(t *testing.T, sb integration.Sandbox){
+	testUnknownCommand,
+	testUnknownFlag,
+}
+
+func testUnknownCommand(t *testing.T, sb integration.Sandbox) {
+	cmd := buildxCmd(sb, withArgs("foo"))
+	out, err := cmd.CombinedOutput()
+	require.Error(t, err, string(out))
+
+	cmd = buildxCmd(sb, withArgs("imagetools", "foo"))
+	out, err = cmd.CombinedOutput()
+	require.Error(t, err, string(out))
+}
+
+func testUnknownFlag(t *testing.T, sb integration.Sandbox) {
+	cmd := buildxCmd(sb, withArgs("build", "--foo=bar"))
+	out, err := cmd.CombinedOutput()
+	require.Error(t, err, string(out))
+}

tests/integration_test.go

@@ -21,6 +21,7 @@ func init() {
 
 func TestIntegration(t *testing.T) {
 	var tests []func(t *testing.T, sb integration.Sandbox)
+	tests = append(tests, commonTests...)
 	tests = append(tests, buildTests...)
 	tests = append(tests, bakeTests...)
 	tests = append(tests, inspectTests...)