getSet() function documented

README.md

@@ -23,6 +23,7 @@ The ideas for the implementation come from
 - Write and Read Values
   - [`set()`](#write-value)
   - [`get()`](#read-value)
+  - [`getSet()`](#read-and-write-value-in-one-step)
   - [`getValues()`](#read-multiple-values)
   - [`getRandomValue()`](#read-random-value)
   - `getValuesSet()` --> Set with values
@@ -222,6 +223,48 @@ store.data["myKey"] // --> "my-value"
 ```
 
 
+## Read and Write Value (in one step)
+
+```typescript
+getSet(key: string, value: any, ttlMs?: number)
+```
+
+Atomically sets key to value and returns the old value stored at key.
+Inspired by: https://docs.keydb.dev/docs/commands/#getset
+
+### key
+
+The key must be a string.
+
+### value
+
+The value can be any object that can be serialized with
+[v8](https://github.com/nodejs/node/blob/main/doc/api/v8.md#serialization-api).
+This means that not only simple data types (string, number) are possible,
+but also more complex types such as sets or maps.
+You can find a list of the
+[supported data types](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm#supported_types) here. 
+
+### ttlMs (optional)
+
+"Time to live" in milliseconds. After this time, 
+the item becomes invalid and is deleted from the database 
+the next time it is accessed or when the application is started.
+Set the value to 0 if you want to explicitly deactivate the process.
+
+### Example
+
+```typescript
+import { BunSqliteKeyValue } from "bun-sqlite-key-value"
+
+const store = new BunSqliteKeyValue()
+
+store.set("key-1", "string-value-1")
+store.getSet("key-1", "string-value-2")) // --> "string-value-1"
+store.get("key-1") // --> "string-value-2"
+```
+
+
 ## Read Multiple Values
 
 ```typescript

package.json

@@ -1,6 +1,6 @@
 {
   "name": "bun-sqlite-key-value",
-  "version": "1.10.5",
+  "version": "1.10.6",
   "author": {
     "name": "Gerold Penz",
     "email": "[email protected]",

tests/memory.test.ts

@@ -514,7 +514,7 @@ test("Append", async () => {
 test("getSet()", async () => {
     const store = new BunSqliteKeyValue()
 
-    store.append(KEY_1, STRING_VALUE_1)
+    store.set(KEY_1, STRING_VALUE_1)
     expect(store.getSet(KEY_1, STRING_VALUE_2)).toEqual(STRING_VALUE_1)
     expect(store.get<string>(KEY_1)).toEqual(STRING_VALUE_2)
 })
@@ -652,5 +652,4 @@ test("hmSet(), hmGet()", async () => {
     const result = store.hmGet(KEY_1, ["field-1", "field-100"])
     expect(result?.["field-1"]).toEqual("value-1")
     expect(result?.["field-100"]).toBeUndefined()
-
 })