How to Handle Errcheck Warnings When Deferring Functions with Return Variables in Go?

Errcheck Warning on Deferring Functions with Return Variables

When deferring a function that returns a variable in Go, linters like gometalinter and errcheck may issue warnings. This is because deferred functions have no accessible return values, leading to potential unhandled errors.

To address this issue, the recommended approach is to wrap the deferred function in another anonymous or named function that captures the error variable.

Here's an example using an anonymous function:

<code class="go">defer func() {
  if err := r.Body.Close(); err != nil {
    // Handle the error
  }
}()</code>

This approach allows the error handling code to be executed immediately after the deferred function, ensuring that any potential error is not discarded.

Alternatively, a helper function can be created to perform the error checking and be deferred instead:

<code class="go">func Check(f func() error) {
  if err := f(); err != nil {
    // Handle the error
  }
}

defer Check(r.Body.Close)</code>

This helper function can be reused for multiple deferred functions, simplifying the error handling process.

For example, a modified helper function can accept multiple functions and execute them in reverse order:

<code class="go">func Checks(fs ...func() error) {
  for i := len(fs) - 1; i >= 0; i-- {
    if err := fs[i](); err != nil {
      // Handle the error
    }
  }
}

defer Checks(r.Body.Close, SomeOtherFunc)</code>

This ensures that the last deferred function is executed first, mimicking the execution order of deferred functions in Go.

The above is the detailed content of How to Handle Errcheck Warnings When Deferring Functions with Return Variables in Go?. For more information, please follow other related articles on the PHP Chinese website!