From b8ca4d491c3ca9e830476e903b4e86a674e8153b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BD=A0=E6=89=8B=E6=8D=A7=E9=B2=9C=E8=8A=B1?=
 <157215725@qq.com>
Date: Sat, 18 Mar 2023 22:54:57 +0800
Subject: [PATCH] fix: `cssRule.style.fontFamily` null safe (close #14)

---
 src/clone-node.ts     | 7 ++++---
 src/embed-web-font.ts | 5 ++++-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/clone-node.ts b/src/clone-node.ts
index 09236ab..37bf0fc 100644
--- a/src/clone-node.ts
+++ b/src/clone-node.ts
@@ -97,9 +97,10 @@ export async function cloneNode<T extends Node>(
       applyCssStyleWithOptions(cloneStyle, context)
     }
 
-    if (cloneStyle.fontFamily) {
-      cloneStyle.fontFamily.split(',').forEach(val => fontFamilies.add(val))
-    }
+    cloneStyle.getPropertyValue('font-family')
+      .split(',')
+      .filter(Boolean)
+      .forEach(val => fontFamilies.add(val))
 
     copyPseudoContent(node, clone, ownerWindow)
 
diff --git a/src/embed-web-font.ts b/src/embed-web-font.ts
index cf5b93a..e7487a3 100644
--- a/src/embed-web-font.ts
+++ b/src/embed-web-font.ts
@@ -78,7 +78,10 @@ export async function embedWebFont<T extends Element>(
       .filter(cssRule => (
         isCssFontFaceRule(cssRule)
         && hasCssUrl(cssRule.style.getPropertyValue('src'))
-        && cssRule.style.fontFamily.split(',').some(val => fontFamilies.has(val))
+        && cssRule.style.getPropertyValue('font-family')
+          .split(',')
+          .filter(Boolean)
+          .some(val => fontFamilies.has(val))
       ))
       .forEach((value) => {
         const rule = value as CSSFontFaceRule