breaking(services): the queue property now if set to an empty string …

…means that the service/endpoint/group will not be in a queue. Clients that specifically assign queue names should experience no changes. And clients that didn't specify a value for the property (so the property was undefined) should also not experience a change and should see their service/endpoint/group use the `q` group. If explicetly set to an empty string ``, the service will NOT be part of a queue. (#114)

breaking(services): the metadata configuration specified when creating the service is now stored read-only, any type of edit on the internal copy will result in a `TypeError` as the metdata object is frozen.

Signed-off-by: Alberto Ricart <[email protected]>

services/src/service.ts

@@ -162,7 +162,7 @@ export class ServiceGroupImpl implements ServiceGroup {
     } else if (parent instanceof ServiceGroupImpl) {
       const sg = parent as ServiceGroupImpl;
       this.srv = sg.srv;
-      if (queue === "" && sg.queue !== "") {
+      if (queue === undefined) {
         queue = sg.queue;
       }
       root = sg.subject;
@@ -198,7 +198,10 @@ export class ServiceGroupImpl implements ServiceGroup {
     return this.srv._addEndpoint(ne);
   }
 
-  addGroup(name = "", queue = ""): ServiceGroup {
+  addGroup(name = "", queue?: string): ServiceGroup {
+    if (queue === undefined) {
+      queue = this.queue;
+    }
     return new ServiceGroupImpl(this, name, queue);
   }
 }
@@ -286,13 +289,18 @@ export class ServiceImpl implements Service {
   ) {
     this.nc = nc;
     this.config = Object.assign({}, config);
-    if (!this.config.queue) {
+    if (this.config.queue === undefined) {
       this.config.queue = "q";
     }
 
+    // don't allow changing metadata
+    config.metadata = Object.freeze(config.metadata || {});
+
     // this will throw if no name
     validateName("name", this.config.name);
-    validateName("queue", this.config.queue);
+    if (this.config.queue) {
+      validateName("queue", this.config.queue);
+    }
 
     // this will throw if not semver
     parseSemVer(this.config.version);

services/src/types.ts

@@ -51,7 +51,8 @@ export type Endpoint = {
   metadata?: Record<string, string>;
   /**
    * Optional queue group to run this particular endpoint in. The service's configuration
-   * queue configuration will be used. See {@link ServiceConfig}.
+   * queue configuration will be used. See {@link ServiceConfig}. Note that if the queue
+   * is set to an empty string, it will not be run in a queue.
    */
   queue?: string;
 };
@@ -81,6 +82,8 @@ export interface ServiceGroup {
    * without requiring editing of the service.
    * Note that an optional queue can be specified, all endpoints added to
    * the group, will use the specified queue unless the endpoint overrides it.
+   * When not set, it uses the parent group configuration. An empty string
+   * means no queue.
    * see {@link EndpointOptions} and {@link ServiceConfig}.
    * @param subject
    * @param queue
@@ -208,9 +211,11 @@ export type ServiceConfig = {
    */
   metadata?: Record<string, string>;
   /**
-   * Optional queue group to run the service in. By default,
-   * then queue name is "q". Note that this configuration will
-   * be the default for all endpoints and groups.
+   * Optional queue group to run the service in. If not set, default,
+   * is set to "q". Note that this configuration will
+   * be the default for all endpoints and groups. If set to an empty
+   * string, the service subscription will NOT have queue, and will
+   * not be run in a queue.
    */
   queue?: string;
 };

services/tests/service_test.ts

@@ -1047,3 +1047,61 @@ Deno.test("service - endpoint default queue group", async () => {
 
   await cleanup(ns, nc);
 });
+
+Deno.test("service - endpoint no queue group", async () => {
+  const { ns, nc } = await setup();
+
+  const svc = new Svc(nc);
+  const srv = await svc.add({
+    name: "example",
+    version: "0.0.1",
+    metadata: { service: "1" },
+    // no queue
+    queue: "",
+  }) as ServiceImpl;
+
+  // svc config doesn't specify a queue group so we expect q
+  srv.addEndpoint("a");
+  checkQueueGroup(srv, "a", "");
+
+  // we add another group, no queue
+  const dg = srv.addGroup("G");
+  dg.addEndpoint("a");
+  checkQueueGroup(srv, "G.a", "");
+
+  // the above have no queue, no override, and set a queue
+  const g = srv.addGroup("g", "qq");
+  g.addEndpoint("a");
+  checkQueueGroup(srv, "g.a", "qq");
+  // override
+  g.addEndpoint("b", { queue: "bb" });
+  checkQueueGroup(srv, "g.b", "bb");
+  // add a subgroup without, should inherit
+  const g2 = g.addGroup("g");
+  g2.addEndpoint("a");
+  checkQueueGroup(srv, "g.g.a", "qq");
+
+  await cleanup(ns, nc);
+});
+
+Deno.test("service - metadata is not editable", async () => {
+  const { ns, nc } = await setup();
+
+  const svc = new Svc(nc);
+  const srv = await svc.add({
+    name: "example",
+    version: "0.0.1",
+    metadata: { service: "1", hello: "world" },
+    queue: "",
+  }) as ServiceImpl;
+
+  assertThrows(
+    () => {
+      srv.config.metadata!.hello = "hello";
+    },
+    TypeError,
+    "Cannot assign to read only property",
+  );
+
+  await cleanup(ns, nc);
+});