Ilia Denisov
43 lines
1.3 KiB
Go
43 lines
1.3 KiB
Go
package membership
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import (
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"errors"
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"fmt"
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)
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// ErrNotFound reports that a membership record was requested but does not
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// exist in the store.
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var ErrNotFound = errors.New("membership not found")
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// ErrConflict reports that a membership mutation could not be applied
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// because the record changed concurrently or failed a compare-and-swap
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// guard.
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var ErrConflict = errors.New("membership conflict")
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// ErrInvalidTransition is the sentinel returned when Transition rejects a
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// `(from, to)` pair.
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var ErrInvalidTransition = errors.New("invalid membership status transition")
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// InvalidTransitionError stores the rejected `(from, to)` pair and wraps
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// ErrInvalidTransition so callers can match it with errors.Is.
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type InvalidTransitionError struct {
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// From stores the source status that was attempted to leave.
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From Status
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// To stores the destination status that was attempted to enter.
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To Status
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}
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// Error reports a human-readable summary of the rejected pair.
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func (err *InvalidTransitionError) Error() string {
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return fmt.Sprintf(
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"invalid membership status transition from %q to %q",
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err.From, err.To,
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)
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}
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// Unwrap returns ErrInvalidTransition so errors.Is recognizes the sentinel.
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func (err *InvalidTransitionError) Unwrap() error {
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return ErrInvalidTransition
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}
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