allow prepending middleware (#2647)

vapor · Jul 12, 2021 · f6a422c · f6a422c
1 parent f94f0bf
commit f6a422c
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Showing 2 changed files with 45 additions and 12 deletions.
diff --git a/Sources/Vapor/Middleware/MiddlewareConfiguration.swift b/Sources/Vapor/Middleware/MiddlewareConfiguration.swift
@@ -4,6 +4,12 @@ public struct Middlewares {
     /// The configured middleware.
     private var storage: [Middleware]
 
+
+    public enum Position {
+      case beginning
+      case end
+    }
+
     /// Create a new, empty `MiddlewareConfig`.
     public init() {
         self.storage = []
@@ -18,8 +24,13 @@ public struct Middlewares {
     /// - warning: Ensure the `Middleware` is thread-safe when using this method.
     ///            Otherwise, use the type-based method and register the `Middleware`
     ///            using factory method to `Services`.
-    public mutating func use(_ middleware: Middleware) {
+    public mutating func use(_ middleware: Middleware, at position: Position = .end) {
+      switch position {
+      case .end:
         self.storage.append(middleware)
+      case .beginning:
+        self.storage.insert(middleware, at: 0)
+      }
     }
 
     /// Resolves the configured middleware for a given container

diff --git a/Tests/VaporTests/MiddlewareTests.swift b/Tests/VaporTests/MiddlewareTests.swift
@@ -1,22 +1,23 @@
 import XCTVapor
 
 final class MiddlewareTests: XCTestCase {
-    func testMiddlewareOrder() throws {
-        final class OrderMiddleware: Middleware {
-            static var order: [String] = []
-            let pos: String
-            init(_ pos: String) {
-                self.pos = pos
-            }
-            func respond(to req: Request, chainingTo next: Responder) -> EventLoopFuture<Response> {
-                OrderMiddleware.order.append(pos)
-                return next.respond(to: req)
-            }
+    final class OrderMiddleware: Middleware {
+        static var order: [String] = []
+        let pos: String
+        init(_ pos: String) {
+            self.pos = pos
+        }
+        func respond(to req: Request, chainingTo next: Responder) -> EventLoopFuture<Response> {
+            OrderMiddleware.order.append(pos)
+            return next.respond(to: req)
         }
+    }
 
+    func testMiddlewareOrder() throws {
         let app = Application(.testing)
         defer { app.shutdown() }
 
+        OrderMiddleware.order = []
         app.grouped(
             OrderMiddleware("a"), OrderMiddleware("b"), OrderMiddleware("c")
         ).get("order") { req -> String in
@@ -30,6 +31,27 @@ final class MiddlewareTests: XCTestCase {
         }
     }
 
+    func testPrependingMiddleware() throws {
+        let app = Application(.testing)
+        defer { app.shutdown() }
+
+        OrderMiddleware.order = []
+        app.middleware.use(OrderMiddleware("b"));
+        app.middleware.use(OrderMiddleware("c"));
+        app.middleware.use(OrderMiddleware("a"), at: .beginning);
+        app.middleware.use(OrderMiddleware("d"), at: .end);
+
+        app.get("order") { req -> String in
+            return "done"
+        }
+
+        try app.testable().test(.GET, "/order") { res in
+            XCTAssertEqual(res.status, .ok)
+            XCTAssertEqual(OrderMiddleware.order, ["a", "b", "c", "d"])
+            XCTAssertEqual(res.body.string, "done")
+        }
+    }
+
     func testCORSMiddlewareVariedByRequestOrigin() throws {
         let app = Application(.testing)
         defer { app.shutdown() }