errutil

func FlattenJoined ¶

func FlattenJoined(err error) []error

FlattenJoined recursively unwraps an errors.Join tree and returns all leaf errors (errors that do not themselves implement Unwrap() []error). The order of leaves matches a depth-first left-to-right traversal of the join tree.

Use this helper to assert that every error produced by a multi-step rollback or shutdown is reachable via errors.Is / errors.As without relying on the exact join structure.

Example:

errs := errutil.FlattenJoined(err)
for _, e := range errs {
    var pe *phaseError
    if errors.As(e, &pe) { ... }
}