feat: Add expiresIn option

README.md

@@ -21,6 +21,7 @@ unless the `client` options is provided to override them.
   ☣️ Legacy reap behaviors use DynamoDB [`scan`](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/clients/client-dynamodb/classes/scancommand.html)
   functionality that can incur significant costs. Should instead enable [DynamoDB TTL](http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html)
   and select the `expires` field. TODO should we just remove it since we're already making a breaking change?
+- `expiresIn` Optional set the number of seconds for DynamoDB TTL. Defaults to the cookie's maxAge.
 
 ## Usage
 
@@ -42,6 +43,8 @@ var options = {
   ],
   // Optional skip throw missing special keys in session, if set true
   skipThrowMissingSpecialKeys: true,
+  // Optional set the number of seconds for DynamoDB TTL
+  expiresIn: 3600,
 };
 ```
 

index.d.ts

@@ -37,6 +37,13 @@ declare namespace ConnectDynamoDB {
      * Useful if the table already exists or if you want to skip existence checks in a serverless environment such as AWS Lambda.
      */
     initialized?: boolean;
+    /**
+     * Set the number of seconds added to the item expiry time.
+     *
+     * Setting this to 0 will use the `maxAge` value from the session cookie.
+     * @default 0
+     */
+    expiresIn?: number;
   }
 
   interface DynamoDBStoreOptionsSpecialKey {

lib/connect-dynamodb.js

@@ -68,6 +68,7 @@ module.exports = function (connect) {
     if (this.reapInterval > 0) {
       this._reap = setInterval(this.reap.bind(this), this.reapInterval);
     }
+    this.expiresIn = null == options.expiresIn ? 0 : options.expiresIn
   }
 
   /*
@@ -344,11 +345,17 @@ module.exports = function (connect) {
    */
   DynamoDBStore.prototype.getExpiresValue = function (sess) {
     const now = Math.floor(Date.now() / 1000);
-    const expires =
+
+    if (this.expiresIn != 0) {
+      return now + this.expiresIn;
+    }
+    else {
+      const expires =
       typeof sess.cookie.maxAge === "number"
         ? now + (sess.cookie.maxAge / 1000)
         : now + oneDayInSeconds;
     return expires;
+    }
   };
 
   /**

test/test.js

@@ -5,6 +5,7 @@ const {
   DynamoDBClient,
   CreateTableCommand,
   DeleteTableCommand,
+  GetItemCommand,
   ScalarAttributeType,
 } = require("@aws-sdk/client-dynamodb");
 const ConnectDynamoDB = require(__dirname + "/../lib/connect-dynamodb.js");
@@ -231,6 +232,40 @@ describe("DynamoDBStore", () => {
         });
       });
     });
+
+    it("should set correct expiry when expiresIn option is set", async () => {
+      const storeWithExpiry = new DynamoDBStore({
+        client: client,
+        table: tableName,
+        expiresIn: 1000
+      });
+      const beforeTime = Math.floor(Date.now() / 1000);
+
+      await new Promise((resolve, reject) => {
+        storeWithExpiry.set(
+          sessionId,
+          {
+            cookie: { maxAge: 2000 },
+            name: "test"
+          },
+          (err) => {
+            if (err) return reject(err);
+            resolve();
+          }
+        );
+      });
+
+      const result = await client.send(
+        new GetItemCommand({
+          TableName: tableName,
+          Key: { id: { S: "sess:" + sessionId } }
+        })
+      );
+
+      const expiryValue = parseInt(result.Item.expires.N);
+      const expectedExpiry = beforeTime + 1000;
+      expiryValue.should.be.approximately(expectedExpiry, 2);
+    });
   });
 
   describe("Getting", () => {