[FEAT] [KV] delete and purge now take an optional sequence. If the cu…

…rrent key is not at the specified revision, the delete/purge fails.

jetstream/kv.ts

@@ -35,6 +35,7 @@ import {
   KV,
   KvCodec,
   KvCodecs,
+  KvDeleteOptions,
   KvEntry,
   KvOptions,
   kvPrefix,
@@ -545,12 +546,12 @@ export class Bucket implements KV, KvRemove {
     }
   }
 
-  purge(k: string): Promise<void> {
-    return this._deleteOrPurge(k, "PURGE");
+  purge(k: string, opts?: Partial<KvDeleteOptions>): Promise<void> {
+    return this._deleteOrPurge(k, "PURGE", opts);
   }
 
-  delete(k: string): Promise<void> {
-    return this._deleteOrPurge(k, "DEL");
+  delete(k: string, opts?: Partial<KvDeleteOptions>): Promise<void> {
+    return this._deleteOrPurge(k, "DEL", opts);
   }
 
   async purgeDeletes(
@@ -590,9 +591,13 @@ export class Bucket implements KV, KvRemove {
     });
   }
 
-  async _deleteOrPurge(k: string, op: "DEL" | "PURGE"): Promise<void> {
+  async _deleteOrPurge(
+    k: string,
+    op: "DEL" | "PURGE",
+    opts?: Partial<KvDeleteOptions>,
+  ): Promise<void> {
     if (!this.hasWildcards(k)) {
-      return this._doDeleteOrPurge(k, op);
+      return this._doDeleteOrPurge(k, op, opts);
     }
     const iter = await this.keys(k);
     const buf: Promise<void>[] = [];
@@ -608,14 +613,21 @@ export class Bucket implements KV, KvRemove {
     }
   }
 
-  async _doDeleteOrPurge(k: string, op: "DEL" | "PURGE"): Promise<void> {
+  async _doDeleteOrPurge(
+    k: string,
+    op: "DEL" | "PURGE",
+    opts?: Partial<KvDeleteOptions>,
+  ): Promise<void> {
     const ek = this.encodeKey(k);
     this.validateKey(ek);
     const h = headers();
     h.set(kvOperationHdr, op);
     if (op === "PURGE") {
       h.set(JsHeaders.RollupHdr, JsHeaders.RollupValueSubject);
     }
+    if (opts?.previousSeq) {
+      h.set(PubHeaders.ExpectedLastSubjectSequenceHdr, `${opts.previousSeq}`);
+    }
     await this.js.publish(this.subjectForKey(ek, true), Empty, { headers: h });
   }
 

jetstream/tests/kv_test.ts

@@ -1966,3 +1966,51 @@ Deno.test("kv - watch start at", async () => {
 
   await cleanup(ns, nc);
 });
+
+Deno.test("kv - delete key if revision", async () => {
+  const { ns, nc } = await setup(
+    jetstreamServerConf({}, true),
+  );
+  if (await notCompatible(ns, nc, "2.6.3")) {
+    return;
+  }
+  const js = nc.jetstream();
+  const b = await js.views.kv(nuid.next());
+  const seq = await b.create("a", Empty);
+  await assertRejects(
+    async () => {
+      await b.delete("a", { previousSeq: 100 });
+    },
+    Error,
+    "wrong last sequence: 1",
+    undefined,
+  );
+
+  await b.delete("a", { previousSeq: seq });
+
+  await cleanup(ns, nc);
+});
+
+Deno.test("kv - purge key if revision", async () => {
+  const { ns, nc } = await setup(
+    jetstreamServerConf({}, true),
+  );
+  if (await notCompatible(ns, nc, "2.6.3")) {
+    return;
+  }
+  const js = nc.jetstream();
+  const b = await js.views.kv(nuid.next());
+  const seq = await b.create("a", Empty);
+
+  await assertRejects(
+    async () => {
+      await b.purge("a", { previousSeq: 2 });
+    },
+    Error,
+    "wrong last sequence: 1",
+    undefined,
+  );
+
+  await b.purge("a", { previousSeq: seq });
+  await cleanup(ns, nc);
+});

jetstream/types.ts

@@ -1238,15 +1238,17 @@ export interface KV extends RoKV {
    * a key or the soft delete marker to be removed without
    * additional notification on a watch.
    * @param k
+   * @param opts
    */
-  delete(k: string): Promise<void>;
+  delete(k: string, opts?: Partial<KvDeleteOptions>): Promise<void>;
 
   /**
    * Deletes and purges the specified key and any value
    * history.
    * @param k
+   * @param opts
    */
-  purge(k: string): Promise<void>;
+  purge(k: string, opts?: Partial<KvDeleteOptions>): Promise<void>;
 
   /**
    * Destroys the underlying stream used by the KV. This
@@ -1263,6 +1265,14 @@ export interface KvPutOptions {
   previousSeq: number;
 }
 
+export interface KvDeleteOptions {
+  /**
+   * If set the KV must be at the current sequence or the
+   * put will fail.
+   */
+  previousSeq: number;
+}
+
 export type ObjectStoreLink = {
   /**
    * name of object store storing the data