Validate max_retries on both target forms (closes #221)

internal/handlers/export_test.go

@@ -27,6 +27,17 @@ const MaxRenderedResponseBytesForTest = maxRenderedResponseBytes
 // per-delivery attempt ceiling to the handlers_test package.
 const MaxRenderedAttemptsForTest = maxRenderedAttempts
 
+// MaxTargetRetriesForTest exposes the target max_retries ceiling to
+// the handlers_test package, so the tests assert against the constant
+// the handlers enforce rather than a number copied beside it.
+const MaxTargetRetriesForTest = maxTargetRetries
+
+// PageOrFirstForTest exposes pageOrFirst for use in the handlers_test
+// package.
+func PageOrFirstForTest(s string) int {
+	return pageOrFirst(s)
+}
+
 // DummyVerificationsForTest reports how many equivalent-cost
 // verifications were charged for usernames that do not exist. It
 // lets a test prove the anti-enumeration path ran without timing