Using generator in givePort() (#2040)

tests/helpers.ts

@@ -1,21 +1,15 @@
-import { map } from "ramda";
+import { map, when, equals, nAry } from "ramda";
 import { z } from "zod";
 import { ezFileBrand } from "../src/file-schema";
 import { SchemaHandler, walkSchema } from "../src/schema-walker";
 
-let lastGivenPort = 8010;
-const reservedPorts = {
-  example: 8090,
-};
-export const givePort = (test?: keyof typeof reservedPorts) => {
-  if (test && reservedPorts[test]) {
-    return reservedPorts[test];
-  }
-  do {
-    lastGivenPort++;
-  } while (Object.values(reservedPorts).includes(lastGivenPort));
-  return lastGivenPort;
-};
+const disposer = (function* () {
+  let port = 8010;
+  while (true) yield port++;
+})();
+
+export const givePort = (test?: "example", rsvd = 8090): number =>
+  test ? rsvd : when(equals(rsvd), nAry(0, givePort))(disposer.next().value);
 
 export const serializeSchemaForTest = (
   subject: z.ZodTypeAny,