Organize backend into product executable and shared Go modules

backend/shared/errors/throttle_test.go

@@ -0,0 +1,35 @@
+package merrors
+
+import (
+	"errors"
+	"testing"
+	"time"
+)
+
+func TestWithThrottlePreservesClassificationAndDetails(t *testing.T) {
+	base := Define("verificationLimited")
+	err := Wrap(
+		WithThrottle(base, " destination ", 45*time.Second, "request is temporarily limited"),
+		"verification failed",
+	)
+
+	if !errors.Is(err, base) {
+		t.Fatalf("throttle error did not preserve classification: %v", err)
+	}
+	details, ok := ThrottleDetailsFrom(err)
+	if !ok {
+		t.Fatal("throttle details were not available through wrapping")
+	}
+	if details.ScopeKind != "destination" || details.RetryAfter != 45*time.Second {
+		t.Fatalf("unexpected throttle details: %+v", details)
+	}
+	if got, want := err.Error(), "verificationLimited: request is temporarily limited: verification failed"; got != want {
+		t.Fatalf("unexpected throttle error text: got=%q want=%q", got, want)
+	}
+}
+
+func TestThrottleDetailsFromRejectsUnannotatedError(t *testing.T) {
+	if details, ok := ThrottleDetailsFrom(ServiceUnavailable("dependency unavailable")); ok {
+		t.Fatalf("unexpected throttle details: %+v", details)
+	}
+}