test: add case for custom variant with pseudo

Author: andreypopp

src/__tests__/fixtures/custom-variant-pseudo.css

@@ -0,0 +1,3 @@
+.Label__custom:hover {
+    color: red
+}

src/__tests__/fixtures/custom-variant-pseudo.js

@@ -0,0 +1,9 @@
+import React from "react";
+import styles from "css";
+export function Label({
+  variant,
+  ...props }) {
+  let className = styles.Label + (variant.custom ? ' ' + styles.Label__custom : '');
+  return React.createElement("div", { ...props, className
+  });
+}

src/__tests__/fixtures/custom-variant-pseudo.react.css

@@ -0,0 +1,3 @@
+Label:custom:hover {
+  color: red;
+}