Add support for pedantic mode in consumer creation (#264)

Introduced a `pedantic` option in `ConsumerApiOptions` to ensure stricter validation of consumer configuration during creation. Updated the `add` method in `jsmconsumer_api.ts` to handle this option, and added a test case to validate pedantic behavior. This enhances flexibility while enforcing stricter checks when needed.

Note the original API allowed for an optional action (a string), now it also allows a ConsumerApiOptions object that allows setting the action and whether it should be pedantic.

Signed-off-by: Alberto Ricart <alberto@synadia.com>

Author: aricart

jetstream/src/jsapi_types.ts

@@ -718,6 +718,14 @@ export type PurgeResponse = Success & {
   purged: number;
 };
 
+/**
+ * Additional options that express the intention of the API
+ */
+export type ConsumerApiOptions = ConsumerApiAction | {
+  action?: ConsumerApiAction;
+  pedantic?: boolean;
+};
+
 export const ConsumerApiAction = {
   CreateOrUpdate: "",
   Update: "update",
@@ -730,6 +738,7 @@ export type CreateConsumerRequest = {
   "stream_name": string;
   config: Partial<ConsumerConfig>;
   action?: ConsumerApiAction;
+  pedantic?: boolean;
 };
 
 export type StreamMsgResponse = ApiResponse & {

jetstream/src/jsmconsumer_api.ts

@@ -30,6 +30,7 @@ import {
   InvalidArgumentError,
 } from "@nats-io/nats-core/internal";
 import type {
+  ConsumerApiOptions,
   ConsumerConfig,
   ConsumerInfo,
   ConsumerListResponse,
@@ -55,10 +56,14 @@ export class ConsumerAPIImpl extends BaseApiClientImpl implements ConsumerAPI {
   async add(
     stream: string,
     cfg: ConsumerConfig,
-    action: ConsumerApiAction = ConsumerApiAction.Create,
+    opts: ConsumerApiOptions = ConsumerApiAction.Create,
   ): Promise<ConsumerInfo> {
     validateStreamName(stream);
 
+    if (typeof opts === "string") {
+      opts = { action: opts as ConsumerApiAction };
+    }
+
     if (cfg.deliver_group && cfg.flow_control) {
       throw InvalidArgumentError.format(
         ["flow_control", "deliver_group"],
@@ -89,7 +94,8 @@ export class ConsumerAPIImpl extends BaseApiClientImpl implements ConsumerAPI {
     const cr = {} as CreateConsumerRequest;
     cr.config = cfg;
     cr.stream_name = stream;
-    cr.action = action;
+    cr.action = opts.action;
+    cr.pedantic = opts.pedantic;
 
     if (cr.config.durable_name) {
       validateDurableName(cr.config.durable_name);

jetstream/src/types.ts

@@ -23,6 +23,7 @@ import type {
 } from "@nats-io/nats-core/internal";
 
 import type {
+  ConsumerApiOptions,
   DeliverPolicy,
   DirectLastFor,
   PullOptions,
@@ -271,7 +272,11 @@ export type ConsumerAPI = {
    * @param stream
    * @param cfg
    */
-  add(stream: string, cfg: Partial<ConsumerConfig>): Promise<ConsumerInfo>;
+  add(
+    stream: string,
+    cfg: Partial<ConsumerConfig>,
+    opts?: ConsumerApiOptions,
+  ): Promise<ConsumerInfo>;
 
   /**
    * Updates the consumer configuration for the specified consumer on the specified

jetstream/tests/jsm_test.ts

@@ -2599,6 +2599,40 @@ Deno.test("jsm - pause/unpause", async () => {
   await cleanup(ns, nc);
 });
 
+Deno.test("jsm - consumer pedantic", async () => {
+  const { ns, nc } = await setup(jetstreamServerConf());
+  const jsm = await jetstreamManager(nc);
+  await jsm.streams.add({
+    name: "A",
+    subjects: ["a"],
+    storage: StorageType.Memory,
+    consumer_limits: {
+      max_ack_pending: 10,
+    },
+  });
+
+  // this should work
+  await jsm.consumers.add("A", {
+    name: "a",
+    ack_policy: AckPolicy.Explicit,
+  });
+
+  // but this should reject
+  await assertRejects(
+    () => {
+      return jsm.consumers.add("A", {
+        name: "b",
+        ack_policy: AckPolicy.Explicit,
+        max_ack_pending: 0,
+      }, { pedantic: true });
+    },
+    Error,
+    "pedantic mode: max_ack_pending must be set if it's configured in stream limits",
+  );
+
+  await cleanup(ns, nc);
+});
+
 Deno.test("jsm - storage", async () => {
   const { ns, nc } = await setup(jetstreamServerConf());