Low Quality Code

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Low Quality Code: A Critical Analysis

In today's fast-paced software development landscape, code quality is more crucial than ever. Unfortunately, many developers fall into the trap of writing low-quality code, which can lead to a plethora of problems, including inefficiency, maintainability issues, and even security vulnerabilities. In this article, we will delve into the world of low-quality code and explore some common pitfalls that developers should avoid.

Blocking Asynchronous Execution (Awaiting Without Cancellation)

One of the most significant issues with low-quality code is the lack of proper asynchronous execution. In the given code snippet, the onGetLastMeetsEvent method awaits the repository call directly, which can lead to race conditions or redundant API calls if the user triggers multiple events rapidly.

Fix: Use CancelableOperation (from async package) or check isClosed before emitting.

if (isClosed) return; // Prevent emitting to a closed Bloc

Inefficient State Updates (Unnecessary Cloning)

Another common issue with low-quality code is inefficient state updates. In the given code snippet, the code always copies the entire list of past meets (state.lastMeets) when appending new results, which can lead to unnecessary memory allocations.

Fix: Instead of lastMeets: [...(state.lastMeets ?? []), ...r], use List.of() to ensure only new elements are added.

lastMeets: List.of(state.lastMeets ?? [])..addAll(r),

Poor Error Handling & Lack of Logging

Low-quality code often lacks proper error handling and logging mechanisms. In the given code snippet, the error handling uses .fold(), but it only updates state with the error message without logging or debugging support.

Fix: Add logging using print() (for development) or a logging package (logger).

result.fold(
  (failure) {
    print('Error fetching meets: ${failure.message}');
    emit(state.copyWith(status: LastMeetsStatus.error, errorMessage: failure.message));
  },
  (data) => emit(state.copyWith(...)),
);

No Cancellation for In-Progress Requests

Low-quality code often fails to implement cancellation for in-progress requests, which can lead to wasted network requests. In the given code snippet, if a new event is triggered before the previous one completes, the previous API call will continue running in the background, even if it's no longer relevant.

Fix: Implement a debounce mechanism using transformEvents.

EventTransformer<T> debounce<T>(Duration duration) {
  return (events, mapper) => events.debounceTime(duration).flatMap(mapper);
}

LastMeetsBloc() : super(LastMeetsState.initial()) {
  on<GetLastMeetsEvent>(onGetLastMeetsEvent, transformer: debounce(Duration(milliseconds: 300)));
}

No Proper Event Queuing

Low-quality code often lacks proper event queuing, which can lead to state inconsistencies if multiple API calls finish in an unexpected order. In the given code snippet, the event handler runs without considering multiple concurrent executions.

Fix: Use SequentialEventTransformer() to queue events instead of running them simultaneously.

on<GetLastMeetsEvent>(onGetLastMeetsEvent, transformer: sequential());

BlocProvider Placement

Low-quality code often fails to place the BlocProvider correctly, which can lead to unnecessary instance creation. In the given code snippet, the LastMeetsBloc is created inside ProfilePage, which means every time this page is rebuilt, a new instance is created.

Fix: Place the BlocProvider higher in the widget tree (e.g., in main.dart or a parent widget) so the bloc is retained across navigations.

return MultiBlocProvider(
  providers: [
    BlocProvider(create: (context) => getIt<LastMeetsBloc>()..add(GetLastMeetsEvent(refresh: true))),
    BlocProvider(create: (context) => getIt<UserBloc>()),
  ],
  child: ProfilePage(),
);

Hardcoded Strings

Low-quality code often contains hardcoded strings, which can make it difficult to support multiple languages. In the given code snippet, the UI texts like 'Profile', 'Edit profile', 'Sign out', and 'Last meets' are hardcoded.

Fix: Use an internationalization/localization solution (intl package) to support multiple languages.

AppLocalizations.of(context).profileTitle

Unused Test Code

Low-quality code often contains unused test code, which can make it difficult to maintain. In the given code snippet, there is a test-only navigation to CreateMeetPage.

Fix: Use kDebugMode from flutter/foundation.dart to enable debugging.

if (kDebugMode) {
  context.push(CreateMeetPage.route);
}

Avoid Using SizedBox for Spacing

Low-quality code often uses SizedBox for spacing, which can make the code look cluttered. In the given code snippet, multiple SizedBox(height: 10,) are used.

Fix: Use Padding or SizedBox.expand() where necessary.

Column(
  children: [
    CircleUserAvatar(...),
    Padding(
      padding: EdgeInsets.symmetric(vertical: 10),
      child: Text(state.userEntity?.bio ?? ''),
    ),
    LastMeetsSection()
  ],
)

Unnecessary Future Return Type in Event Handlers

Low-quality code often contains unnecessary future return types in event handlers, which can make the code look cluttered. In the given code snippet, the event handlers (e.g., onGetMeetEvent) all return Future.

Fix: Remove the unnecessary future return type.

void onGetMeetEvent(GetMeetEvent event, Emitter<MeetState> emit) async {

Repetitive Code Everywhere

Low-quality code often contains repetitive code everywhere, which can make the code look cluttered. In the given code snippet, every method follows the same structure.

Fix: Extract common handling logic into a helper method.

Future<void> _execute<T>(
    Future<T> Function() operation,
    Emitter<MeetState> emit,
    MeetStatus successStatus,
    {MeetStatus? errorStatus}
  ) async {
  emit(state.copyWith(status: MeetStatus.loading));
  
  var result = await operation();
  
  result.fold(
    (l) => emit(state.copyWith(
      status: errorStatus ?? MeetStatus.error, 
      errorMessage: l.message
    )),
    (r) => emit(state.copyWith(status: successStatus, meetEntity: r is MeetEntity ? r : state.meetEntity)),
  );
}

Avoiding Unnecessary state.meetEntity Null Checks

Low-quality code often contains unnecessary null checks, which can make the code look cluttered. In the given code snippet, the null check is done using if (state.meetEntity == null).

Fix: Throw an exception instead.

void onJoinMeetEvent(JoinMeetEvent event, Emitter<MeetState> emit) {
  if (state.meetEntity == null) {
    throw StateError("onJoinMeetEvent called without an active meet");
  }
  _execute(() => meetRepository.joinMeet(state.meetEntity!.id), emit, MeetStatus.success);
}

state.copyWith is Too Verbose

Low-quality code often contains verbose code, which can make the code look cluttered. In the given code snippet, the state.copyWith is used to update the status.

Fix: Use a simple helper method.

void _setStatus(MeetStatus status, Emitter<MeetState> emit) {
  emit(state.copyWith(status: status));
}

Event Handlers Shouldn’t Add More Events

Low-quality code often contains event handlers that add more events, which can cause event storms. In the given code snippet, the event handler onGetMeetEvent adds a new event.

Fix: Make the event handler optional.

void onGetMeetEvent(GetMeetEvent event, Emitter<MeetState> emit) {
  _execute(() => meetRepository.getMeet(event.meetId), emit, MeetStatus.success);
}

MeetStatus.success is Meaningless

Low-quality code often contains meaningless status values, which can make the code look cluttered. In the given code snippet, the MeetStatus.success is used for everything.

Fix: Use more specific status values.

enum MeetStatus { loading, success, joined, kicked, transferred, canceled, left, error }

In conclusion, low-quality code can lead to a plethora of problems, including inefficiency, maintainability issues, and even security vulnerabilities. By following the best practices outlined in this article, developers can write high-quality code that is efficient, maintainable, and secure. Remember, code quality is not just a matter of personal preference, but a critical aspect of software development that can have a significant impact on the success of a project.
Low Quality Code: A Q&A Article

In our previous article, we discussed the importance of writing high-quality code and explored some common pitfalls that developers should avoid. In this article, we will answer some frequently asked questions about low-quality code and provide additional insights on how to improve your coding skills.

Q: What is low-quality code?

A: Low-quality code is code that is inefficient, difficult to maintain, and prone to errors. It may contain repetitive code, unnecessary null checks, and meaningless status values, among other issues.

Q: Why is low-quality code a problem?

A: Low-quality code can lead to a plethora of problems, including inefficiency, maintainability issues, and even security vulnerabilities. It can also make it difficult for other developers to understand and maintain your code, which can lead to frustration and delays.

Q: How can I identify low-quality code?

A: You can identify low-quality code by looking for the following signs:

  • Repetitive code
  • Unnecessary null checks
  • Meaningless status values
  • Inefficient state updates
  • Poor error handling
  • Lack of logging and debugging support

Q: How can I improve my coding skills?

A: To improve your coding skills, you should:

  • Practice writing clean and efficient code
  • Learn from others and seek feedback
  • Stay up-to-date with the latest programming trends and best practices
  • Participate in coding challenges and exercises
  • Join online communities and forums to connect with other developers

Q: What are some common mistakes that developers make when writing code?

A: Some common mistakes that developers make when writing code include:

  • Writing repetitive code
  • Failing to handle errors properly
  • Using meaningless status values
  • Failing to log and debug their code
  • Using unnecessary null checks
  • Failing to follow best practices and coding standards

Q: How can I avoid writing low-quality code?

A: To avoid writing low-quality code, you should:

  • Follow best practices and coding standards
  • Write clean and efficient code
  • Use meaningful status values
  • Log and debug your code properly
  • Avoid repetitive code and unnecessary null checks
  • Seek feedback and learn from others

Q: What are some tools and resources that can help me improve my coding skills?

A: Some tools and resources that can help you improve your coding skills include:

  • Online coding platforms and communities (e.g. GitHub, Stack Overflow)
  • Coding books and tutorials (e.g. "Clean Code" by Robert C. Martin)
  • Online courses and training programs (e.g. Udemy, Coursera)
  • Code review tools and services (e.g. CodeClimate, Codacy)
  • Pair programming and code review with other developers

Q: How can I get feedback on my code?

A: You can get feedback on your code by:

  • Sharing your code with other developers and asking for feedback
  • Joining online communities and forums to connect with other developers
  • Participating in code review sessions and workshops
  • Using code review tools and services
  • Seeking feedback from experienced developers and mentors

In conclusion, low-quality code can lead to a plethora of problems, including inefficiency, maintainability issues, and even security vulnerabilities. By following the best practices outlined in this article and seeking feedback from others, you can improve your coding skills and write high-quality code that is efficient, maintainable, and secure. Remember, code quality is not just a matter of personal preference, but a critical aspect of software development that can have a significant impact on the success of a project.