client: Define separate errors instead of IsErrXXX functions

Signed-off-by: Evgenii Baidakov <evgenii@nspcc.io>

client/errors_test.go

@@ -4,65 +4,68 @@ import (
 	"fmt"
 	"testing"
 
-	"github.com/nspcc-dev/neofs-sdk-go/client"
 	apistatus "github.com/nspcc-dev/neofs-sdk-go/client/status"
 	"github.com/stretchr/testify/require"
 )
 
 func TestErrors(t *testing.T) {
 	for _, tc := range []struct {
-		check func(error) bool
+		errs        []error
-		errs  []error
+		errVariable error
 	}{
 		{
-			check: client.IsErrContainerNotFound,
 			errs: []error{
 				apistatus.ContainerNotFound{},
 				new(apistatus.ContainerNotFound),
 			},
+			errVariable: apistatus.ErrContainerNotFound,
 		},
 		{
-			check: client.IsErrEACLNotFound,
 			errs: []error{
 				apistatus.EACLNotFound{},
 				new(apistatus.EACLNotFound),
 			},
+			errVariable: apistatus.ErrEACLNotFound,
 		},
 		{
-			check: client.IsErrObjectNotFound,
 			errs: []error{
 				apistatus.ObjectNotFound{},
 				new(apistatus.ObjectNotFound),
 			},
+			errVariable: apistatus.ErrObjectNotFound,
 		},
 		{
-			check: client.IsErrObjectAlreadyRemoved,
 			errs: []error{
 				apistatus.ObjectAlreadyRemoved{},
 				new(apistatus.ObjectAlreadyRemoved),
 			},
+			errVariable: apistatus.ErrObjectAlreadyRemoved,
 		},
 		{
-			check: client.IsErrSessionExpired,
 			errs: []error{
 				apistatus.SessionTokenExpired{},
 				new(apistatus.SessionTokenExpired),
 			},
+			errVariable: apistatus.ErrSessionTokenExpired,
 		}, {
-			check: client.IsErrSessionNotFound,
 			errs: []error{
 				apistatus.SessionTokenNotFound{},
 				new(apistatus.SessionTokenNotFound),
 			},
+			errVariable: apistatus.ErrSessionTokenNotFound,
 		},
 	} {
 		require.NotEmpty(t, tc.errs)
+		require.NotNil(t, tc.errVariable)
 
 		for i := range tc.errs {
-			require.True(t, tc.check(tc.errs[i]), tc.errs[i])
+			require.ErrorIs(t, tc.errs[i], tc.errVariable)
-			require.True(t, tc.check(fmt.Errorf("top-level context: :%w",
+
-				fmt.Errorf("inner context: %w", tc.errs[i])),
+			wrapped := fmt.Errorf("some message %w", tc.errs[i])
-			), tc.errs[i])
+			require.ErrorIs(t, wrapped, tc.errVariable)
+
+			wrappedTwice := fmt.Errorf("another message %w", wrapped)
+			require.ErrorIs(t, wrappedTwice, tc.errVariable)
 		}
 	}
 }

client/status/container.go

@@ -5,8 +5,17 @@ import (
 	"github.com/nspcc-dev/neofs-api-go/v2/status"
 )
 
+var (
+	// ErrEACLNotFound is an instance of EACLNotFound error status. It's expected to be used for [errors.Is]
+	// and MUST NOT be changed.
+	ErrEACLNotFound EACLNotFound
+	// ErrContainerNotFound is an instance of ContainerNotFound error status. It's expected to be used for [errors.Is]
+	// and MUST NOT be changed.
+	ErrContainerNotFound ContainerNotFound
+)
+
 // ContainerNotFound describes status of the failure because of the missing container.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type ContainerNotFound struct {
 	v2 status.Status
 }
@@ -25,6 +34,16 @@ func (x ContainerNotFound) Error() string {
 	)
 }
 
+// Is implements interface for correct checking current error type with [errors.Is].
+func (x ContainerNotFound) Is(target error) bool {
+	switch target.(type) {
+	default:
+		return false
+	case ContainerNotFound, *ContainerNotFound:
+		return true
+	}
+}
+
 // implements local interface defined in FromStatusV2 func.
 func (x *ContainerNotFound) fromStatusV2(st *status.Status) {
 	x.v2 = *st
@@ -44,7 +63,7 @@ func (x ContainerNotFound) ToStatusV2() *status.Status {
 
 // EACLNotFound describes status of the failure because of the missing eACL
 // table.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type EACLNotFound struct {
 	v2 status.Status
 }
@@ -63,6 +82,16 @@ func (x EACLNotFound) Error() string {
 	)
 }
 
+// Is implements interface for correct checking current error type with [errors.Is].
+func (x EACLNotFound) Is(target error) bool {
+	switch target.(type) {
+	default:
+		return false
+	case EACLNotFound, *EACLNotFound:
+		return true
+	}
+}
+
 // implements local interface defined in FromStatusV2 func.
 func (x *EACLNotFound) fromStatusV2(st *status.Status) {
 	x.v2 = *st

client/status/object.go

@@ -5,8 +5,17 @@ import (
 	"github.com/nspcc-dev/neofs-api-go/v2/status"
 )
 
+var (
+	// ErrObjectAlreadyRemoved is an instance of ObjectAlreadyRemoved error status. It's expected to be used for [errors.Is]
+	// and MUST NOT be changed.
+	ErrObjectAlreadyRemoved ObjectAlreadyRemoved
+	// ErrObjectNotFound is an instance of ObjectNotFound error status. It's expected to be used for [errors.Is]
+	// and MUST NOT be changed.
+	ErrObjectNotFound ObjectNotFound
+)
+
 // ObjectLocked describes status of the failure because of the locked object.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type ObjectLocked struct {
 	v2 status.Status
 }
@@ -43,7 +52,7 @@ func (x ObjectLocked) ToStatusV2() *status.Status {
 }
 
 // LockNonRegularObject describes status returned on locking the non-regular object.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type LockNonRegularObject struct {
 	v2 status.Status
 }
@@ -80,7 +89,7 @@ func (x LockNonRegularObject) ToStatusV2() *status.Status {
 }
 
 // ObjectAccessDenied describes status of the failure because of the access control violation.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type ObjectAccessDenied struct {
 	v2 status.Status
 }
@@ -128,7 +137,7 @@ func (x ObjectAccessDenied) Reason() string {
 }
 
 // ObjectNotFound describes status of the failure because of the missing object.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type ObjectNotFound struct {
 	v2 status.Status
 }
@@ -147,6 +156,16 @@ func (x ObjectNotFound) Error() string {
 	)
 }
 
+// Is implements interface for correct checking current error type with [errors.Is].
+func (x ObjectNotFound) Is(target error) bool {
+	switch target.(type) {
+	default:
+		return false
+	case ObjectNotFound, *ObjectNotFound:
+		return true
+	}
+}
+
 // implements local interface defined in FromStatusV2 func.
 func (x *ObjectNotFound) fromStatusV2(st *status.Status) {
 	x.v2 = *st
@@ -184,6 +203,16 @@ func (x ObjectAlreadyRemoved) Error() string {
 	)
 }
 
+// Is implements interface for correct checking current error type with [errors.Is].
+func (x ObjectAlreadyRemoved) Is(target error) bool {
+	switch target.(type) {
+	default:
+		return false
+	case ObjectAlreadyRemoved, *ObjectAlreadyRemoved:
+		return true
+	}
+}
+
 // implements local interface defined in FromStatusV2 func.
 func (x *ObjectAlreadyRemoved) fromStatusV2(st *status.Status) {
 	x.v2 = *st
@@ -203,7 +232,7 @@ func (x ObjectAlreadyRemoved) ToStatusV2() *status.Status {
 
 // ObjectOutOfRange describes status of the failure because of the incorrect
 // provided object ranges.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type ObjectOutOfRange struct {
 	v2 status.Status
 }

client/status/session.go

@@ -5,8 +5,17 @@ import (
 	"github.com/nspcc-dev/neofs-api-go/v2/status"
 )
 
+var (
+	// ErrSessionTokenNotFound is an instance of SessionTokenNotFound error status. It's expected to be used for [errors.Is]
+	// and MUST NOT be changed.
+	ErrSessionTokenNotFound SessionTokenNotFound
+	// ErrSessionTokenExpired is an instance of SessionTokenExpired error status. It's expected to be used for [errors.Is]
+	// and MUST NOT be changed.
+	ErrSessionTokenExpired SessionTokenExpired
+)
+
 // SessionTokenNotFound describes status of the failure because of the missing session token.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type SessionTokenNotFound struct {
 	v2 status.Status
 }
@@ -25,6 +34,16 @@ func (x SessionTokenNotFound) Error() string {
 	)
 }
 
+// Is implements interface for correct checking current error type with [errors.Is].
+func (x SessionTokenNotFound) Is(target error) bool {
+	switch target.(type) {
+	default:
+		return false
+	case SessionTokenNotFound, *SessionTokenNotFound:
+		return true
+	}
+}
+
 // implements local interface defined in FromStatusV2 func.
 func (x *SessionTokenNotFound) fromStatusV2(st *status.Status) {
 	x.v2 = *st
@@ -43,7 +62,7 @@ func (x SessionTokenNotFound) ToStatusV2() *status.Status {
 }
 
 // SessionTokenExpired describes status of the failure because of the expired session token.
-// Instances provide Status and StatusV2 interfaces.
+// Instances provide [Status], [StatusV2] and error interfaces.
 type SessionTokenExpired struct {
 	v2 status.Status
 }
@@ -62,6 +81,16 @@ func (x SessionTokenExpired) Error() string {
 	)
 }
 
+// Is implements interface for correct checking current error type with [errors.Is].
+func (x SessionTokenExpired) Is(target error) bool {
+	switch target.(type) {
+	default:
+		return false
+	case SessionTokenExpired, *SessionTokenExpired:
+		return true
+	}
+}
+
 // implements local interface defined in FromStatusV2 func.
 func (x *SessionTokenExpired) fromStatusV2(st *status.Status) {
 	x.v2 = *st