make keyed Environment objects type aware

fix a bug

Meridian/EnvironmentValues.swift

@@ -0,0 +1,34 @@
+//
+//  EnvironmentStorage.swift
+//  Meridian
+//
+//  Created by Soroush Khanlou on 8/29/20.
+//
+
+import Foundation
+
+public protocol EnvironmentKey {
+
+    associatedtype Value
+
+    static var defaultValue: Value { get }
+
+}
+
+public final class EnvironmentValues {
+
+    static let shared = EnvironmentValues()
+
+    var objects: [AnyObject] = []
+
+    var keyedObjects: [Any] = []
+
+    public subscript<Key: EnvironmentKey>(key: Key.Type) -> Key.Value {
+        get {
+            keyedObjects.lazy.compactMap({ $0 as? Key.Value }).first ?? Key.defaultValue
+        }
+        set {
+            keyedObjects.append(newValue)
+        }
+    }
+}

Meridian/OptionsRoute.swift

@@ -7,16 +7,27 @@
 
 import Foundation
 
-extension EnvironmentKey {
-    static let routes = EnvironmentKey()
+struct RouterEnvironmentKey: EnvironmentKey {
+    static var defaultValue = Router(routesByPrefix: [:], defaultErrorRenderer: BasicErrorRenderer.self)
+}
+
+extension EnvironmentValues {
+    var router: Router {
+        get {
+            self[RouterEnvironmentKey.self]
+        }
+        set {
+            self[RouterEnvironmentKey.self] = newValue
+        }
+    }
 }
 
 struct OptionsRoute: Route {
     static var route = RouteMatcher(matches: { header in
         header.method == .OPTIONS ? MatchedRoute() : nil
     })
 
-    @Environment(.routes) var router: Router
+    @Environment(\.router) var router
 
     @Path var path: String
 

Meridian/Property Wrappers/Environment.swift

@@ -11,21 +11,17 @@ public typealias EnvironmentObject<Type> = Custom<EnvironmentObjectExtractor<Typ
 
 public struct EnvironmentObjectExtractor<Type>: NonParameterizedExtractor {
     public static func extract(from context: RequestContext) throws -> Type {
-        guard let value = EnvironmentStorage.shared.objects.lazy.compactMap({ $0 as? Type }).first else {
+        guard let value = EnvironmentValues.shared.objects.lazy.compactMap({ $0 as? Type }).first else {
             throw MissingEnvironmentObject(type: Type.self)
         }
         return value
     }
 }
 
-public typealias Environment<Type> = CustomWithParameters<EnvironmentKeyExtractor<Type>>
+public typealias Environment<Value> = CustomWithParameters<EnvironmentKeyExtractor<Value>>
 
-public struct EnvironmentKeyExtractor<Type>: ParameterizedExtractor {
-    public static func extract(from context: RequestContext, parameters: EnvironmentKey) throws -> Type {
-        if let value = EnvironmentStorage.shared.keyedObjects[parameters] as? Type {
-            return value
-        } else {
-            throw MissingEnvironmentObject(type: Type.self)
-        }
+public struct EnvironmentKeyExtractor<Value>: ParameterizedExtractor {
+    public static func extract(from context: RequestContext, parameters: KeyPath<EnvironmentValues, Value>) throws -> Value {
+        EnvironmentValues.shared[keyPath: parameters]
     }
 }

Meridian/Server.swift

@@ -66,7 +66,7 @@ public final class Server {
 
     public func listen() {
 
-        EnvironmentStorage.shared.keyedObjects[.routes] = self.router
+        EnvironmentValues.shared[RouterEnvironmentKey.self] = self.router
 
         let reuseAddrOpt = ChannelOptions.socket(SocketOptionLevel(SOL_SOCKET), SO_REUSEADDR)
 
@@ -99,12 +99,12 @@ public final class Server {
 
 extension Server {
     public func environmentObject(_ object: AnyObject) -> Self {
-        EnvironmentStorage.shared.objects.append(object)
+        EnvironmentValues.shared.objects.append(object)
         return self
     }
 
-    public func environment(_ key: EnvironmentKey, _ value: AnyObject) -> Self {
-        EnvironmentStorage.shared.keyedObjects[key] = value
+    public func environment<Key: EnvironmentKey>(_ key: Key, _ value: Key.Value) -> Self {
+//        EnvironmentValues.shared.keyedObjects[key] = value
         return self
     }
 }

MeridianTests/EnvironmentTests.swift

@@ -10,14 +10,26 @@ import NIO
 import NIOHTTP1
 @testable import Meridian
 
-extension EnvironmentKey {
-    static let formatter = EnvironmentKey()
+struct NumberFormatterEnvironmentKey: EnvironmentKey {
+    static var defaultValue = NumberFormatter()
 }
 
+extension EnvironmentValues {
+    var formatter: NumberFormatter {
+        get {
+            self[NumberFormatterEnvironmentKey.self]
+        }
+        set {
+            self[NumberFormatterEnvironmentKey.self] = newValue
+        }
+    }
+}
+
+
 struct EnvironmentKeyTestRoute: Route {
     static let route: RouteMatcher = "/environmentKey"
 
-    @Environment(.formatter) var formatter: NumberFormatter
+    @Environment(\.formatter) var formatter
 
     func execute() throws -> Response {
         formatter.string(from: 343) ?? "formatter couldn't format"
@@ -65,9 +77,9 @@ final class EnvironmentTests: XCTestCase {
         let formatter = NumberFormatter()
         formatter.locale = Locale(identifier: "en_US")
         formatter.numberStyle = .spellOut
-        EnvironmentStorage.shared.keyedObjects[.formatter] = formatter
+        EnvironmentValues.shared[NumberFormatterEnvironmentKey.self] = formatter
 
-        EnvironmentStorage.shared.objects.append(Database())
+        EnvironmentValues.shared.objects.append(Database())
 
         return channel
     }