Use errors.Is for nested error checking

looplab · Jan 28, 2021 · 59477d5 · 59477d5
1 parent dc0f6b1
commit 59477d5
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Showing 3 changed files with 4 additions and 3 deletions.
diff --git a/aggregatestore/model/aggregatestore.go b/aggregatestore/model/aggregatestore.go
@@ -53,7 +53,7 @@ func NewAggregateStore(repo eh.ReadWriteRepo, eventHandler eh.EventHandler) (*Ag
 // Load implements the Load method of the eventhorizon.AggregateStore interface.
 func (r *AggregateStore) Load(ctx context.Context, aggregateType eh.AggregateType, id uuid.UUID) (eh.Aggregate, error) {
 	item, err := r.repo.Find(ctx, id)
-	if rrErr, ok := err.(eh.RepoError); ok && rrErr.Err == eh.ErrEntityNotFound {
+	if errors.Is(err, eh.ErrEntityNotFound) {
 		// Create the aggregate.
 		if item, err = eh.CreateAggregate(aggregateType, id); err != nil {
 			return nil, err

diff --git a/examples/guestlist/domains/guestlist/projectors.go b/examples/guestlist/domains/guestlist/projectors.go
@@ -147,7 +147,7 @@ func (p *GuestListProjector) HandleEvent(ctx context.Context, event eh.Event) er
 	// Load or create the guest list.
 	var g *GuestList
 	m, err := p.repo.Find(ctx, p.eventID)
-	if rrErr, ok := err.(eh.RepoError); ok && rrErr.Err == eh.ErrEntityNotFound {
+	if errors.Is(err, eh.ErrEntityNotFound) {
 		g = &GuestList{
 			ID: p.eventID,
 		}

diff --git a/httputils/query.go b/httputils/query.go
@@ -16,6 +16,7 @@ package httputils
 
 import (
 	"encoding/json"
+	"errors"
 	"net/http"
 	"path"
 
@@ -53,7 +54,7 @@ func QueryHandler(repo eh.ReadRepo) http.Handler {
 			}
 
 			if data, err = repo.Find(r.Context(), id); err != nil {
-				if rrErr, ok := err.(eh.RepoError); ok && rrErr.Err == eh.ErrEntityNotFound {
+				if errors.Is(err, eh.ErrEntityNotFound) {
 					http.Error(w, "could not find item", http.StatusNotFound)
 					return
 				}