api: match permanent sentinel errors after backoff unwrapping (#32197)

api/error_test.go

@@ -0,0 +1,27 @@
+package api
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/cenkalti/backoff/v4"
+	"github.com/stretchr/testify/assert"
+)
+
+// Backoff returns permanent errors unwrapped. These must still match the sentinel.
+func TestPermanentSentinels(t *testing.T) {
+	for _, tc := range []struct{ err, other error }{
+		{ErrNotAvailable, ErrUnsupportedPlatform},
+		{ErrUnsupportedPlatform, ErrNotAvailable},
+		{ErrMissingCredentials, ErrMissingToken},
+		{ErrMissingToken, ErrMissingCredentials},
+	} {
+		_, unwrapped := backoff.RetryWithData(func() (int, error) {
+			return 0, tc.err
+		}, &backoff.StopBackOff{})
+
+		assert.ErrorIs(t, unwrapped, tc.err)
+		assert.ErrorIs(t, fmt.Errorf("wrapped: %w", unwrapped), tc.err)
+		assert.NotErrorIs(t, unwrapped, tc.other)
+	}
+}