errutil

errutil

Package errutil annotates errors with caller location, joins cleanup failures onto an existing error, and enumerates the errors inside an errors.Join value.

• Trace annotates an error with runtime caller metadata (file, line, function) while preserving the original error with %w wrapping, so errors.Is and errors.As continue to work.
• JoinFnError executes an error-producing function and joins its result into an existing error value using errors.Join, for defer/cleanup logic where secondary failures must not overwrite the primary error.
• Errors enumerates the individual errors aggregated within an errors.Join value, returning a single-element slice for a plain error and nil for nil.
• Trace(nil) returns nil, and JoinFnError supports nil and non-nil combinations through errors.Join semantics.

When To Use

• Errors cross several layers and the origin must survive the trip.
• You want consistent wrapping rather than ad-hoc fmt.Errorf calls.

Example

err := errors.New("example error")
testErr := errutil.Trace(err)

fmt.Println(testErr)

Full source is in example_errutil_test.go. More runnable examples are on pkg.go.dev.

Dependencies

This package reaches no external module: it uses only the Go standard library.

Links

• Reference documentation
• Package page
• All nurago packages