Code Smell 166 - Low-Level Errors on User Interface

Fatal error: Uncaught Error: Class 'logs_queries_web' not found in /var/www/html/query-line.php:78 Stack trace: #0 {main} thrown in /var/www/html/query-line.php on line 718

TL;DR: Catch your errors. Even the ones you don't expect.

Problems

• Security

• Error Handling

• Error Logging

• Bad UX Experience

Solutions

1. Use a top-level handler

2. Avoid languages favoring return codes

3. Expect database and low-level errors

Context

Even in 2022, we can see "serious" websites showing casual users a stack or debugging message.

Sample Code

Wrong

<?



Fatal error: Uncaught Error: Class 'MyClass' 

  not found in /nstest/src/Container.php:9

Right

<?



// A user-defined exception handler function

function myException($exception) {

    logError($exception->description())

    // We don't show Exception to final users      

}



// Set user-defined exception handler function

set_exception_handler("myException");

Detection

[X] Automatic

We can use mutation testing to simulate problems and see if they are handled correctly.

Tags

• Security

Conclusion

We need to keep maturing.

Our solutions shouldn't be sloppy.

We need to improve our reputation as serious software engineers.

Relations

Code Smell 72 - Return Codes

Maxi Contieri ・ May 28 '21

#webdev #programming #codenewbie #tutorial

More Info

Fail Fast

Maxi Contieri ・ Dec 6 '20

#codenewbie #programming #webdev #oop

Disclaimer

Code Smells are just my opinion.

Credits

Photo by jesse orrico on Unsplash

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80 percent of my problems are simple logic errors. 80 percent of the remaining problems are pointer errors. The remaining problems are hard.

Mark Donner

Software Engineering Great Quotes

Maxi Contieri ・ Dec 28 '20

#codenewbie #programming #quotes #software

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This article is part of the CodeSmell Series.

How to Find the Stinky parts of your Code

Maxi Contieri ・ May 21 '21

#codenewbie #tutorial #codequality #beginners