ContainerImage.Pinniped/internal/multierror/multierror.go

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// Copyright 2020 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Package multierror provides a type that can translate multiple errors into a Go error interface.
//
// A common use of this package is as follows.
// errs := multierror.New()
// for i := range stuff {
// err := doThing(i)
// errs.Add(err)
// }
// return errs.ErrOrNil()
package multierror
import (
"fmt"
"strings"
)
// formatFunc is a function used to format the string representing of a MultiError. It is used in the
// Error() function.
//
// It is marked out here to indicate how we could potentially extend MultiError in the future to
// support more styles of converting from a list of error's to a string.
//nolint: gochecknoglobals
var formatFunc func(errs MultiError, sb *strings.Builder) = defaultFormat
// MultiError holds a list of error's, that could potentially be empty.
//
// Use New() to create a MultiError.
type MultiError []error
// New returns an empty MultiError.
func New() MultiError {
return make([]error, 0)
}
// Add adds an error to the MultiError. The provided err must not be nil.
func (m *MultiError) Add(err error) {
*m = append(*m, err)
}
// Error implements the error.Error() interface method.
func (m MultiError) Error() string {
sb := strings.Builder{}
formatFunc(m, &sb)
return sb.String()
}
// ErrOrNil returns either nil, if there are no errors in this MultiError, or an error, otherwise.
func (m MultiError) ErrOrNil() error {
if len(m) > 0 {
return m
}
return nil
}
func defaultFormat(errs MultiError, sb *strings.Builder) {
_, _ = fmt.Fprintf(sb, "%d error(s):", len(errs))
for _, err := range errs {
_, _ = fmt.Fprintf(sb, "\n- %s", err.Error())
}
}