Add simple type test for design components (#49538)

web/packages/design/src/styled-components.type-test.tsx

@@ -0,0 +1,37 @@
+/**
+ * Teleport
+ * Copyright (C) 2024 Gravitational, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import Box from './Box';
+
+/**
+ * TypeTest is supposed to catch regressions in the types for our design components.
+ *
+ * The file name specifically uses the "type-test.tsx" suffix so that this file isn't ran by Jest.
+ */
+export const TypeTest = () => (
+  <Box>
+    <Box
+      // @ts-expect-error Prop that doesn't exist on Box.
+      nonexistentprop
+    />
+    <Box
+      // @ts-expect-error Valid prop but invalid value type.
+      alignSelf={2}
+    />
+  </Box>
+);