fix: restore Theme 2 font families

test/unit/specs/services/style_setter/style_setter.spec.js

@@ -0,0 +1,24 @@
+import { hasInvalidCachedThemeRules } from 'src/services/style_setter/style_setter.js'
+
+describe('style setter cache', () => {
+  it('rejects cached rules containing serialized objects', () => {
+    expect(
+      hasInvalidCachedThemeRules([
+        ['html { --font: [object Object]; }'],
+        ['.post { --font: sans-serif; }'],
+      ]),
+    ).to.equal(true)
+  })
+
+  it('accepts cached rules containing valid font families', () => {
+    expect(
+      hasInvalidCachedThemeRules([
+        ['html { --font: sans-serif; }'],
+        [
+          '.post { --font: "Atkinson Hyperlegible"; }',
+          '.post::after { content: "[object Object]"; }',
+        ],
+      ]),
+    ).to.equal(false)
+  })
+})