From dfed9b0bc7f3565ece68b416c3455c4ba259b306 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=99=B3=E5=BB=B7=E5=AE=89?=
 <73953029+nrps9909@users.noreply.github.com>
Date: Fri, 28 Aug 2026 20:19:33 +0800
Subject: [PATCH 1/2] fix: handle missing style container

---
 src/Dom/dynamicCSS.ts     | 24 ++++++++++++++++++++++--
 tests/dynamicCSS.test.tsx | 24 ++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/src/Dom/dynamicCSS.ts b/src/Dom/dynamicCSS.ts
index 1abf1b7f..5a566d3d 100644
--- a/src/Dom/dynamicCSS.ts
+++ b/src/Dom/dynamicCSS.ts
@@ -51,7 +51,11 @@ function getOrder(prepend?: Prepend): AppendType {
 /**
  * Find style which inject by rc-util
  */
-function findStyles(container: ContainerType) {
+function findStyles(container: ContainerType | null) {
+  if (!container) {
+    return [];
+  }
+
   return Array.from(
     (containerCache.get(container) || container).children,
   ).filter(node => node.tagName === 'STYLE') as HTMLStyleElement[];
@@ -79,6 +83,10 @@ export function injectCSS(css: string, option: Options = {}) {
   styleNode.innerHTML = css;
 
   const container = getContainer(option);
+  if (!container) {
+    return null;
+  }
+
   const { firstChild } = container;
 
   if (prepend) {
@@ -132,7 +140,7 @@ export function removeCSS(key: string, option: Options = {}) {
   const existNode = findExistNode(key, option);
   if (existNode) {
     const container = getContainer(option);
-    container.removeChild(existNode);
+    container?.removeChild(existNode);
   }
 }
 
@@ -145,6 +153,10 @@ function syncRealContainer(container: ContainerType, option: Options) {
   // Find real container when not cached or cached container removed
   if (!cachedRealContainer || !contains(document, cachedRealContainer)) {
     const placeholderStyle = injectCSS('', option);
+    if (!placeholderStyle) {
+      return;
+    }
+
     const { parentNode } = placeholderStyle;
     containerCache.set(container, parentNode);
     container.removeChild(placeholderStyle);
@@ -164,6 +176,10 @@ export function updateCSS(
   originOption: Options = {},
 ) {
   const container = getContainer(originOption);
+  if (!container) {
+    return null;
+  }
+
   const styles = findStyles(container);
   const option = { ...originOption, styles };
 
@@ -185,6 +201,10 @@ export function updateCSS(
   }
 
   const newNode = injectCSS(css, option);
+  if (!newNode) {
+    return null;
+  }
+
   newNode.setAttribute(getMark(option), key);
   return newNode;
 }
diff --git a/tests/dynamicCSS.test.tsx b/tests/dynamicCSS.test.tsx
index 0b3b5db2..9d616731 100644
--- a/tests/dynamicCSS.test.tsx
+++ b/tests/dynamicCSS.test.tsx
@@ -34,6 +34,18 @@ describe('dynamicCSS', () => {
       expect(document.querySelector('style').nonce).toEqual('light');
     });
 
+    it('does not throw when the document has no style container', () => {
+      const { head, body } = document;
+      head.remove();
+      body.remove();
+
+      try {
+        expect(injectCSS(TEST_STYLE)).toBeNull();
+      } finally {
+        document.documentElement.append(head, body);
+      }
+    });
+
     describe('prepend', () => {
       function testPrepend() {
         const head = document.querySelector('head');
@@ -138,6 +150,18 @@ describe('dynamicCSS', () => {
       expect(document.querySelector('style').innerHTML).toEqual(REPLACE_STYLE);
     });
 
+    it('does not throw when the document has no style container', () => {
+      const { head, body } = document;
+      head.remove();
+      body.remove();
+
+      try {
+        expect(updateCSS(TEST_STYLE, 'missing-container')).toBeNull();
+      } finally {
+        document.documentElement.append(head, body);
+      }
+    });
+
     it('replace with CSP', () => {
       const REPLACE_STYLE = '.bamboo { context: "little" }';
       updateCSS(REPLACE_STYLE, 'unique', { csp: { nonce: 'only' } });

From 0a7b162f207c9f67ba3f90172af861497437f28e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=99=B3=E5=BB=B7=E5=AE=89?=
 <73953029+nrps9909@users.noreply.github.com>
Date: Sun, 20 Sep 2026 14:52:41 +0800
Subject: [PATCH 2/2] test: cover transient style container removal

---
 tests/dynamicCSS.test.tsx | 41 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/tests/dynamicCSS.test.tsx b/tests/dynamicCSS.test.tsx
index 9d616731..1cc97d1d 100644
--- a/tests/dynamicCSS.test.tsx
+++ b/tests/dynamicCSS.test.tsx
@@ -130,6 +130,47 @@ describe('dynamicCSS', () => {
     expect(document.querySelector('style')).toBeFalsy();
   });
 
+  it('can remove styles while the default container is unavailable', () => {
+    const { head, body } = document;
+    const style = updateCSS(TEST_STYLE, 'detached');
+    head.remove();
+    body.remove();
+    try {
+      expect(() => removeCSS('detached')).not.toThrow();
+      expect(() => removeCSS('detached', { styles: [style] })).not.toThrow();
+      expect(style.parentNode).toBe(head);
+    } finally {
+      document.documentElement.append(head, body);
+      removeCSS('detached');
+      clearContainerCache();
+    }
+  });
+
+  it('returns null when the document containers disappear during style creation', () => {
+    clearContainerCache();
+    const { head, body } = document;
+    const createElement = document.createElement.bind(document);
+    const spy = jest
+      .spyOn(document, 'createElement')
+      .mockImplementationOnce(tagName => {
+        head.remove();
+        body.remove();
+        return createElement(tagName);
+      });
+    try {
+      expect(updateCSS(TEST_STYLE, 'transient')).toBeNull();
+      expect(head.querySelector('style')).toBeNull();
+    } finally {
+      spy.mockRestore();
+      document.documentElement.append(head, body);
+      clearContainerCache();
+    }
+    const restored = updateCSS(TEST_STYLE, 'transient');
+    expect(restored.parentNode).toBe(head);
+    removeCSS('transient');
+    clearContainerCache();
+  });
+
   describe('updateCSS', () => {
     beforeEach(() => {
       updateCSS(TEST_STYLE, 'unique');