Use strings for outcome instead of numeric constants

Ref: cloudflare/workerd#961

Author: mrbbot

packages/miniflare/src/plugins/queues/gateway.ts

@@ -14,18 +14,17 @@ const DEFAULT_BATCH_TIMEOUT = 1; // second
 const DEFAULT_RETRIES = 2;
 
 // https://github.com/cloudflare/workerd/blob/01b87642f4eac932aa9074d7e5eec4fd3c90968a/src/workerd/io/outcome.capnp
-const Outcome = {
-  UNKNOWN: 0,
-  OK: 1,
-  EXCEPTION: 2,
-  EXCEEDED_CPU: 3,
-  KILL_SWITCH: 4,
-  DAEMON_DOWN: 5,
-  SCRIPT_NOT_FOUND: 6,
-  CANCELED: 7,
-  EXCEEDED_MEMORY: 8,
-} as const;
-const OutcomeSchema = z.nativeEnum(Outcome);
+const OutcomeSchema = z.enum([
+  "unknown",
+  "ok",
+  "exception",
+  "exceededCpu",
+  "killSwitch",
+  "daemonDown",
+  "scriptNotFound",
+  "cancelled",
+  "exceededMemory",
+]);
 
 const QueueResponseSchema = z.object({
   outcome: OutcomeSchema,
@@ -37,7 +36,7 @@ const QueueResponseSchema = z.object({
 });
 type QueueResponse = z.infer<typeof QueueResponseSchema>;
 const exceptionQueueResponse: QueueResponse = {
-  outcome: Outcome.EXCEPTION,
+  outcome: "exception",
   retryAll: false,
   ackAll: false,
   explicitRetries: [],
@@ -153,7 +152,7 @@ export class QueuesGateway {
 
     // Get messages to retry. If dispatching the batch failed for any reason,
     // retry all messages.
-    const retryAll = response.retryAll || response.outcome !== Outcome.OK;
+    const retryAll = response.retryAll || response.outcome !== "ok";
     const explicitRetries = new Set(response.explicitRetries);
 
     let failedMessages = 0;