support styled-components v6

.travis.yml

@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-  - 'lts/*'
+  - "lts/*"
 branches:
   only:
-    - master
+    - main

src/utils.js

@@ -5,18 +5,19 @@ if (!__PRIVATE__) {
   throw new Error('Could neither find styled-components secret internals');
 }
 
-const { masterSheet } = __PRIVATE__;
+const { mainSheet, masterSheet } = __PRIVATE__;
 
+const sheet = mainSheet || masterSheet;
 const isServer = () => typeof document === 'undefined';
 
 const resetStyleSheet = () => {
-  masterSheet.names = new Map();
-  masterSheet.clearTag();
+  sheet.names = new Map();
+  sheet.clearTag();
 };
 
-const getHTML = () => (isServer() ? new ServerStyleSheet().getStyleTags() : masterSheet.toString());
+const getHTML = () => (isServer() ? new ServerStyleSheet().getStyleTags() : sheet.toString());
 
-const extract = regex => {
+const extract = (regex) => {
   let style = '';
   let matches;
 
@@ -33,8 +34,8 @@ const getCSS = () => css.parse(getStyle());
 const getHashes = () => {
   const hashes = new Set();
 
-  for (const [masterHash, childHashSet] of masterSheet.names) {
-    hashes.add(masterHash);
+  for (const [mainHash, childHashSet] of sheet.names) {
+    hashes.add(mainHash);
 
     for (const childHash of childHashSet) hashes.add(childHash);
   }

test/utils.spec.js

@@ -1,12 +1,18 @@
 const {
-  __PRIVATE__: { masterSheet },
+  __PRIVATE__: { mainSheet, masterSheet },
 } = require('styled-components');
 
 const { getHashes } = require('../src/utils');
 
+const sheet = mainSheet || masterSheet;
+
 it('extracts hashes', () => {
-  masterSheet.names = new Map([['sc-1', new Set(['a'])], ['sc-2', new Set(['b', 'c'])], ['sc-3', new Set(['d', 'e'])]]);
-  masterSheet.toString = function() {
+  sheet.names = new Map([
+    ['sc-1', new Set(['a'])],
+    ['sc-2', new Set(['b', 'c'])],
+    ['sc-3', new Set(['d', 'e'])],
+  ]);
+  sheet.toString = function() {
     return `
       <style data-styled="active">
         .sc-1 {}