31773ecfbf
Before this change the Errors type in the union backend produced errors which could not be Unwrapped to test their type. This adds the (go1.20) Unwrap method to the Errors type which allows errors.Is to work on these errors. It also adds unit tests for the Errors type and fixes a couple of minor bugs thrown up in the process. See: https://forum.rclone.org/t/failed-to-set-modification-time-1-error-pcloud-cant-set-modified-time/38596
76 lines
1.4 KiB
Go
76 lines
1.4 KiB
Go
package union
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import (
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"bytes"
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"fmt"
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)
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// The Errors type wraps a slice of errors
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type Errors []error
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// Map returns a copy of the error slice with all its errors modified
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// according to the mapping function. If mapping returns nil,
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// the error is dropped from the error slice with no replacement.
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func (e Errors) Map(mapping func(error) error) Errors {
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s := make([]error, len(e))
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i := 0
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for _, err := range e {
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nerr := mapping(err)
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if nerr == nil {
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continue
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}
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s[i] = nerr
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i++
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}
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return Errors(s[:i])
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}
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// FilterNil returns the Errors without nil
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func (e Errors) FilterNil() Errors {
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ne := e.Map(func(err error) error {
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return err
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})
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return ne
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}
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// Err returns an error interface that filtered nil,
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// or nil if no non-nil Error is presented.
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func (e Errors) Err() error {
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ne := e.FilterNil()
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if len(ne) == 0 {
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return nil
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}
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return ne
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}
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// Error returns a concatenated string of the contained errors
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func (e Errors) Error() string {
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var buf bytes.Buffer
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if len(e) == 0 {
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buf.WriteString("no error")
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} else if len(e) == 1 {
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buf.WriteString("1 error: ")
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} else {
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fmt.Fprintf(&buf, "%d errors: ", len(e))
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}
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for i, err := range e {
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if i != 0 {
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buf.WriteString("; ")
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}
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if err != nil {
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buf.WriteString(err.Error())
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} else {
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buf.WriteString("nil error")
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}
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}
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return buf.String()
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}
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// Unwrap returns the wrapped errors
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func (e Errors) Unwrap() []error {
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return e
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}
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