logerrcapture

Overview ¶

Package logerrcapture implements robust error handling in defer statements using provided logger.

The Close a `io.Closer` interface or execute any function that returns error safely while logging error. It's often forgotten but it's a caller responsibility to close all implementations of `Closer`, such as *os.File or io.ReaderCloser. Commonly we would use:

defer closer.Close()

This is wrong. Close() usually return important error (e.g for os.File the actual file flush might happen and fail on `Close` method). It's very important to *always* check error. `logerrcapture` provides utility functions to capture error and log it via provided logger, while still allowing to put them in a convenient `defer` statement:

	func <...>(...) (err error) {
 	...
 	defer logerrcapture.Do(logger, closer.Close, "log format message")

		...
	}

If Close returns error, `logerrcapture.Do` will capture it, add to input error if not nil and return by argument.

Example:

func DoAndClose(f *os.File, logger logerrcapture.Logger) error {
	defer logerrcapture.Do(logger, f.Close, "close file at the end")

	// Do something...
	if err := do(); err != nil {
		return err
	}

	return nil
}

The logerrcapture.ExhaustClose function provide the same functionality but takes an io.ReadCloser and exhausts the whole reader before closing. This is useful when trying to use http keep-alive connections because for the same connection to be re-used the whole response body needs to be exhausted.

Recommended: Check https://pkgo.dev/github.com/efficientgo/tools/pkg/errcapture if you want to return error instead of just logging (causing hard error).