Add test, fix style

__tests__/parseObjectStyles.test.js

@@ -123,6 +123,32 @@ test('it parses nested media queries', () => {
   `)
 })
 
+test('it bubbles nested screen rules', () => {
+  const result = parseObjectStyles({
+    '.foo': {
+      backgroundColor: 'red',
+      color: 'white',
+      padding: '1rem',
+      '@screen sm': {
+        backgroundColor: 'orange',
+      },
+    },
+  })
+
+  expect(css(result)).toMatchCss(`
+    .foo {
+      background-color: red;
+      color: white;
+      padding: 1rem;
+    }
+    @screen sm {
+      .foo {
+        background-color: orange;
+      }
+    }
+  `)
+})
+
 test('it parses pseudo-selectors in nested media queries', () => {
   const result = parseObjectStyles({
     '.foo': {

src/util/parseObjectStyles.js

@@ -8,8 +8,13 @@ export default function parseObjectStyles(styles) {
     return parseObjectStyles([styles])
   }
 
-  return _.flatMap(
-    styles,
-    style => postcss([postcssNested({ bubble: ['screen'] })]).process(style, { parser: postcssJs }).root.nodes
-  )
+  return _.flatMap(styles, style => {
+    return postcss([
+      postcssNested({
+        bubble: ['screen'],
+      }),
+    ]).process(style, {
+      parser: postcssJs,
+    }).root.nodes
+  })
 }