Decode query params for WebSocket APIs (#107)

APIGatewayWebSocketRequest was not decoding url query parameters from
event payloads.

### Motivation:

API Gateway WebSocket endpoints do support capturing and forwarding
query parameters. Probably just omitted because it isn't particularly
common.

### Modifications:

Added the field. Added a test. Verified against a real system that uses
the feature.

### Result:

Query parameters for APIGatewayWebSocketRequest will be available to
clients.

Author: mattmassicotte

Sources/AWSLambdaEvents/APIGateway+WebSockets.swift

@@ -39,13 +39,15 @@ public struct APIGatewayWebSocketRequest: Codable {
     }
 
     public let headers: HTTPHeaders?
+    public let queryStringParameters: [String: String]?
     public let multiValueHeaders: HTTPMultiValueHeaders?
     public let context: Context
     public let body: String?
     public let isBase64Encoded: Bool?
 
     enum CodingKeys: String, CodingKey {
         case headers
+        case queryStringParameters
         case multiValueHeaders
         case context = "requestContext"
         case body

Tests/AWSLambdaEventsTests/APIGateway+WebsocketsTests.swift

@@ -65,6 +65,54 @@ class APIGatewayWebSocketsTests {
         }
         """
 
+    static let exampleConnectEventBodyWithQueryParams = """
+        {
+          "headers": {
+            "Host": "lqrlmblaa2.execute-api.us-east-1.amazonaws.com",
+            "Origin": "wss://lqrlmblaa2.execute-api.us-east-1.amazonaws.com",
+            "Sec-WebSocket-Extensions": "",
+            "Sec-WebSocket-Key": "am5ubWVpbHd3bmNyYXF0ag==",
+            "Sec-WebSocket-Version": "13",
+            "X-Amzn-Trace-Id": "Root=1-64b83950-42de8e247b4c2b43091ef67c",
+            "X-Forwarded-For": "24.148.42.16",
+            "X-Forwarded-Port": "443",
+            "X-Forwarded-Proto": "https"
+          },
+          "queryStringParameters":{
+            "foo":"bar"
+          },
+          "multiValueHeaders": {
+            "Host": [ "lqrlmblaa2.execute-api.us-east-1.amazonaws.com" ],
+            "Origin": [ "wss://lqrlmblaa2.execute-api.us-east-1.amazonaws.com" ],
+            "Sec-WebSocket-Extensions": [
+              "permessage-deflate; client_max_window_bits; server_max_window_bits=15"
+            ],
+            "Sec-WebSocket-Key": [ "am5ubWVpbHd3bmNyYXF0ag==" ],
+            "Sec-WebSocket-Version": [ "13" ],
+            "X-Amzn-Trace-Id": [ "Root=1-64b83950-42de8e247b4c2b43091ef67c" ],
+            "X-Forwarded-For": [ "24.148.42.16" ],
+            "X-Forwarded-Port": [ "443" ],
+            "X-Forwarded-Proto": [ "https" ]
+          },
+          "requestContext": {
+            "routeKey": "$connect",
+            "eventType": "CONNECT",
+            "extendedRequestId": "IU3kkGyEoAMFwZQ=",
+            "requestTime": "19/Jul/2023:19:28:16 +0000",
+            "messageDirection": "IN",
+            "stage": "dev",
+            "connectedAt": 1689794896145,
+            "requestTimeEpoch": 1689794896162,
+            "identity": { "sourceIp": "24.148.42.16" },
+            "requestId": "IU3kkGyEoAMFwZQ=",
+            "domainName": "lqrlmblaa2.execute-api.us-east-1.amazonaws.com",
+            "connectionId": "IU3kkeN4IAMCJwA=",
+            "apiId": "lqrlmblaa2"
+          },
+          "isBase64Encoded": false
+        }
+        """
+
     // MARK: - Request -
 
     // MARK: Decoding
@@ -76,4 +124,11 @@ class APIGatewayWebSocketsTests {
         #expect(req.context.connectionId == "IU3kkeN4IAMCJwA=")
         #expect(req.body == nil)
     }
+
+    @Test func testRequestDecodingExampleWithQueryParams() async throws {
+        let data = APIGatewayWebSocketsTests.exampleConnectEventBodyWithQueryParams.data(using: .utf8)!
+        let req = try JSONDecoder().decode(APIGatewayWebSocketRequest.self, from: data)
+
+        #expect(req.queryStringParameters?["foo"] == "bar")
+    }
 }