allow for mixed case header names

Author: sebsto

Sources/EventSource/ALB/ALBTargetGroup+HTTPRequest.swift

@@ -20,12 +20,16 @@ extension ALBTargetGroupRequest {
 
     /// Return an `HTTPRequest` for this `ALBTargetGroupRequest`
     public func httpRequest() throws -> HTTPRequest {
-        HTTPRequest(
+        let headers = self.headers ?? [:]
+        let scheme = headers.first { $0.key.lowercased() == "x-forwarded-proto" }?.value
+        let authority = headers.first { $0.key.lowercased() == "host" }?.value
+        
+        return HTTPRequest(
             method: self.httpMethod,
-            scheme: self.headers?["X-Forwarded-Proto"],
-            authority: self.headers?["Host"],
+            scheme: scheme,
+            authority: authority,
             path: self.path,
-            headerFields: self.headers?.httpFields() ?? [:]
+            headerFields: headers.httpFields()
         )
     }
 }

Tests/OpenAPILambdaTests/ALBConversionTests.swift

@@ -111,8 +111,8 @@ struct ALBConversionTests {
 
         let httpRequest = try albRequest.httpRequest()
 
-        #expect(httpRequest.scheme == nil)
-        #expect(httpRequest.authority == nil)
+        #expect(httpRequest.scheme == "https")
+        #expect(httpRequest.authority == "lambda-alb-123578498.us-east-1.elb.amazonaws.com")
     }
 
     @Test("HTTPResponse to ALB response conversion")