TypeError: Cannot Read Properties of Undefined (Reading 'javascript') in ItemPage Component

[bronglil]

Issue: TypeError in ItemPage Component

Description:

In the Leetcode page the ItemPage component, a TypeError occurs when attempting to access a JavaScript property on itemData, which causes the application to crash. This error seems to be due to itemData being undefined at the time of property access.

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Steps to Reproduce

1. Navigate to the ItemPage component.
2. Ensure itemData is populated in the Leetcode table.
3. Observe the console error when attempting to render the component.

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Expected Outcome

The component should render without errors, displaying information contained within the itemData.javascript property.

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Actual Outcome

The application crashes with a TypeError indicating that itemData is undefined when attempting to access its properties

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Code Context

Below is a code snippet from the ItemPage component where the error occurs:

// Code that may cause the issue
const languageData = itemData.javascript; // `javascript` property may be undefined in `itemData`

Data Structure Requirements

The itemData object passed to the ItemPage component should contain a javascript property to avoid this error. Expected structure:

{
  "id": "123",
  "name": "Example Problem",
  "javascript": "solution code here",
  ...
}

Environment Details

• Language: JavaScript
• React Version: 18.0.0
• Browser: Chrome
• Node.js Version: 20.0.9
• Operating System: Windows 10, macOS
• Development Environment: Local
• App Version: 1.1.1

Attached Error and Logs

Recent Changes

no Changes

Error Messages - Console Output

isit https://reactjs.org/link/error-boundaries to learn more about error boundaries.
logCapturedError @ react-dom.development.js:18704
update.callback @ react-dom.development.js:18737
callCallback @ react-dom.development.js:15036
commitUpdateQueue @ react-dom.development.js:15057
commitLayoutEffectOnFiber @ react-dom.development.js:23430
commitLayoutMountEffects_complete @ react-dom.development.js:24727
commitLayoutEffects_begin @ react-dom.development.js:24713
commitLayoutEffects @ react-dom.development.js:24651
commitRootImpl @ react-dom.development.js:26862
commitRoot @ react-dom.development.js:26721
finishConcurrentRender @ react-dom.development.js:25931
performConcurrentWorkOnRoot @ react-dom.development.js:25848
workLoop @ scheduler.development.js:266
flushWork @ scheduler.development.js:239
performWorkUntilDeadline @ scheduler.development.js:533
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ItemPage.jsx:26 Uncaught TypeError: Cannot read properties of undefined (reading 'javascript')
    at ItemPage (ItemPage.jsx:26:1)
    at renderWithHooks (react-dom.development.js:15486:1)
    at mountIndeterminateComponent (react-dom.development.js:20103:1)
    at beginWork (react-dom.development.js:21626:1)
    at beginWork$1 (react-dom.development.js:27465:1)
    at performUnitOfWork (react-dom.development.js:26596:1)
    at workLoopSync (react-dom.development.js:26505:1)
    at renderRootSync (react-dom.development.js:26473:1)
    at recoverFromConcurrentError (react-dom.development.js:25889:1)
    at performConcurrentWorkOnRoot (react-dom.development.js:25789:1) 

Suggested Investigation and Potential Fixes

Root Cause Analysis
Confirm whether all instances of itemData are expected to include the javascript property. Check the data source for consistency and investigate why some itemData objects might lack this property.

Data Validation
Ensure that the itemData object consistently includes the javascript property when passed to the ItemPage component. This may involve validation or restructuring at the data source to standardize the data.

Fallback Value
Implement a fallback or default value for javascript in the ItemPage component to handle cases where itemData lacks this property. Example:

const languageData = itemData?.javascript ?? "No solution available";

Conditional Checks
Add a conditional check to confirm the presence of the javascript property before accessing it:

const languageData = itemData && itemData.javascript ? itemData.javascript : "No solution available";

Automated Data Consistency Test

To avoid similar issues in the future, implement a test case to check the consistency of itemData properties, ensuring that all required fields are present.