docs: correct CAS/CAD parameter name and update example (redis#3156)

Author: PavelPashov

README.md

@@ -230,10 +230,10 @@ client.scanIterator({
 
 ```typescript
 // Conditionally update only if the current value matches
-await client.set("key", "new-value", { condition: "IFEQ", conditionValue: "old-value" });
+await client.set("key", "new-value", { condition: "IFEQ", matchValue: "old-value" });
 
 // Conditionally delete only if the current value matches
-await client.delEx("key", { condition: "IFEQ", conditionValue: "expected-value" });
+await client.delEx("key", { condition: "IFEQ", matchValue: "expected-value" });
 ```
 
 #### Local Digest
@@ -251,7 +251,7 @@ import { digest } from "redis";
 
 const hash = await digest("my-value");
 
-await client.set("key", "new-value", { condition: "IFDEQ", conditionValue: hash });
+await client.set("key", "new-value", { condition: "IFDEQ", matchValue: hash });
 ```
 
 ### Disconnecting

examples/README.md

@@ -12,6 +12,7 @@ This folder contains example scripts showing how to use Node Redis in different
 | `connect-to-cluster.js`                  | Connect to a Redis cluster.                                                                                                                          |
 | `count-min-sketch.js`                    | Estimate the frequency of a given event using the [RedisBloom](https://redisbloom.io) Count-Min Sketch.                                              |
 | `cuckoo-filter.js`                       | Space efficient set membership checks with a [Cuckoo Filter](https://en.wikipedia.org/wiki/Cuckoo_filter) using [RedisBloom](https://redisbloom.io). |
+| `cas-cad-digest.js`                      | Atomic compare-and-set (CAS) and compare-and-delete (CAD) using digests for single-key optimistic concurrency control.                              |
 | `dump-and-restore.js`                    | Demonstrates the use of the [`DUMP`](https://redis.io/commands/dump/) and [`RESTORE`](https://redis.io/commands/restore/) commands                   |
 | `get-server-time.js`                     | Get the time from the Redis server.                                                                                                                  |
 | `hyperloglog.js`                         | Showing use of Hyperloglog commands [PFADD, PFCOUNT and PFMERGE](https://redis.io/commands/?group=hyperloglog).                                      |

examples/cas-cad-digest.js

@@ -0,0 +1,51 @@
+// Atomic compare-and-set (CAS) and compare-and-delete (CAD) using digests
+// for single-key optimistic concurrency control. 
+// Requires Redis 8.4+ and the @node-rs/xxhash package.
+
+import { createClient, digest } from 'redis';
+
+const client = createClient();
+
+await client.connect();
+
+// Basic Digest Usage: get digest from Redis and verify with client-side calculation
+await client.set('mykey', 'myvalue');
+const serverDigest = await client.digest('mykey');
+const clientDigest = await digest('myvalue');
+console.log(`Server digest: ${serverDigest}`);
+console.log(`Client digest: ${clientDigest}`);
+console.log(`Digests match: ${serverDigest === clientDigest}`);
+
+// Optimistic Locking with IFDEQ: update only if digest matches
+await client.set('mycounter', '100');
+const currentDigest = await digest('100');
+
+// Update only if digest matches
+const result1 = await client.set('mycounter', '150', {
+  condition: 'IFDEQ',
+  matchValue: currentDigest
+});
+console.log(`Update with matching digest: ${result1}`); // 'OK'
+
+// IFDNE: update only if digest does NOT match
+await client.set('myversion', 'v1.0.0');
+const unwantedDigest = await digest('v0.9.0');
+
+const result2 = await client.set('myversion', 'v2.0.0', {
+  condition: 'IFDNE',
+  matchValue: unwantedDigest
+});
+console.log(`Update when digest differs: ${result2}`); // 'OK'
+
+// Conditional Delete with DELEX
+await client.set('mysession', 'sessiondata');
+const sessionDigest = await digest('sessiondata');
+
+// Delete only if digest matches
+const deleted = await client.delEx('mysession', {
+  condition: 'IFDEQ',
+  matchValue: sessionDigest
+});
+console.log(`Deleted with correct digest: ${deleted}`); // 1
+
+client.close();