Merge pull request #2974 from digitalfabrik/2924-security-error

2924: Catch SecurityError when accessing localStorage

release-notes/unreleased/2924-security-error.yml

@@ -0,0 +1,5 @@
+issue_key: 2924
+show_in_stores: false
+platforms:
+  - web
+en: Fix crashes if local storage is not available

web/src/hooks/__tests__/useLocalStorage.spec.tsx

@@ -0,0 +1,75 @@
+import { fireEvent, render } from '@testing-library/react'
+import React from 'react'
+
+import Button from '../../components/base/Button'
+import useLocalStorage from '../useLocalStorage'
+
+describe('useLocalStorage', () => {
+  const key = 'my_storage_key'
+  const MockComponent = () => {
+    const { value, updateLocalStorageItem } = useLocalStorage({ key, initialValue: 0 })
+    return (
+      <div>
+        {value}
+        <Button label='increment' onClick={() => updateLocalStorageItem(value + 1)}>
+          Increment
+        </Button>
+      </div>
+    )
+  }
+
+  beforeEach(() => {
+    jest.clearAllMocks()
+    localStorage.clear()
+  })
+
+  it('should correctly set initial value and update value', () => {
+    const { getByText } = render(<MockComponent />)
+
+    expect(getByText(0)).toBeTruthy()
+    expect(localStorage.getItem(key)).toBe('0')
+
+    fireEvent.click(getByText('Increment'))
+
+    expect(getByText(1)).toBeTruthy()
+    expect(localStorage.getItem(key)).toBe('1')
+
+    fireEvent.click(getByText('Increment'))
+    fireEvent.click(getByText('Increment'))
+    fireEvent.click(getByText('Increment'))
+
+    expect(getByText(4)).toBeTruthy()
+    expect(localStorage.getItem(key)).toBe('4')
+  })
+
+  it('should not use initial value if already set', () => {
+    localStorage.setItem(key, '10')
+    const { getByText } = render(<MockComponent />)
+
+    expect(getByText(10)).toBeTruthy()
+    expect(localStorage.getItem(key)).toBe('10')
+
+    fireEvent.click(getByText('Increment'))
+
+    expect(getByText(11)).toBeTruthy()
+    expect(localStorage.getItem(key)).toBe('11')
+  })
+
+  it('should continue to work even if local storage is not usable', () => {
+    localStorage.getItem = () => {
+      throw new Error('SecurityError')
+    }
+    localStorage.setItem = () => {
+      throw new Error('SecurityError')
+    }
+    const { getByText } = render(<MockComponent />)
+
+    expect(getByText(0)).toBeTruthy()
+    expect(localStorage.getItem(key)).toBe('0')
+
+    fireEvent.click(getByText('Increment'))
+
+    expect(getByText(1)).toBeTruthy()
+    expect(localStorage.getItem(key)).toBe('1')
+  })
+})

web/src/hooks/useLocalStorage.ts

@@ -1,5 +1,7 @@
 import { useState, useCallback } from 'react'
 
+import { reportError } from '../utils/sentry'
+
 type UseLocalStorageProps<T> = {
   key: string
   initialValue: T
@@ -12,17 +14,35 @@ type UseLocalStorageReturn<T> = {
 
 const useLocalStorage = <T>({ key, initialValue }: UseLocalStorageProps<T>): UseLocalStorageReturn<T> => {
   const [value, setValue] = useState<T>(() => {
-    const localStorageItem = localStorage.getItem(key)
-    if (localStorageItem) {
-      return JSON.parse(localStorageItem)
+    try {
+      const localStorageItem = localStorage.getItem(key)
+      if (localStorageItem) {
+        return JSON.parse(localStorageItem)
+      }
+      localStorage.setItem(key, JSON.stringify(initialValue))
+    } catch (e) {
+      // Prevent the following error crashing the app if the browser blocks access to local storage (see #2924)
+      // SecurityError: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
+      const accessDenied = e instanceof Error && e.message.includes('Access is denied for this document')
+      if (!accessDenied) {
+        reportError(e)
+      }
     }
-    localStorage.setItem(key, JSON.stringify(initialValue))
     return initialValue
   })
 
   const updateLocalStorageItem = useCallback(
     (newValue: T) => {
-      localStorage.setItem(key, JSON.stringify(newValue))
+      try {
+        localStorage.setItem(key, JSON.stringify(newValue))
+      } catch (e) {
+        // Prevent the following error crashing the app if the browser blocks access to local storage (see #2924)
+        // SecurityError: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
+        const accessDenied = e instanceof Error && e.message.includes('Access is denied for this document')
+        if (!accessDenied) {
+          reportError(e)
+        }
+      }
       setValue(newValue)
     },
     [key],