Initial commit.

2026-08-19 23:19:08 +02:00
commit 22e737d9c2
153 changed files with 11680 additions and 0 deletions
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+import Foundation
+import HTTPTypes
+import Hummingbird
+
+/// Appends header names to the `Vary` header of every response passing through.
+///
+/// Placed just above the response-compression middleware, it marks each response as varying on `Accept-Encoding`: the static files and pre-rendered
+/// pages are served with `Cache-Control: public`, so without the signal a shared cache could store a compressed body and hand it to a client that
+/// never advertised support for the encoding.
+///
+/// Names already present on a response's `Vary` header — such as the `Accept-Language` the localized pages carry — are kept, and duplicates are not
+/// added.
+public struct VaryMiddleware<Context: RequestContext>: Sendable {
+
+    // MARK: Properties
+
+    /// The header names appended to every response's `Vary` header.
+    private let names: [String]
+
+    // MARK: Initializers
+
+    /// Creates a vary middleware.
+    /// - Parameter fields: the header names appended to every response's `Vary` header. Defaults to `Accept-Encoding`, the request header
+    ///   the response-compression middleware acts on.
+    public init(
+        fields: [HTTPField.Name] = [.acceptEncoding]
+    ) {
+        self.names = fields.map(\.rawName)
+    }
+
+}
+
+// MARK: - RouterMiddleware
+
+extension VaryMiddleware: RouterMiddleware {
+
+    // MARK: Functions
+
+    /// Passes the request down the chain and appends the configured names to the response's `Vary` header on the way back up.
+    /// - Parameters:
+    ///   - request: the incoming request.
+    ///   - context: the context the request is resolved against.
+    ///   - next: the next responder in the middleware chain.
+    /// - Returns: the downstream response with the `Vary` names applied.
+    /// - Throws: any error thrown downstream.
+    public func handle(
+        _ request: Request,
+        context: Context,
+        next: (Request, Context) async throws -> Response
+    ) async throws -> Response {
+        var response = try await next(
+            request,
+            context
+        )
+
+        var vary = response.headers[.vary]?
+            .split(separator: ",")
+            .map { $0.trimmingCharacters(in: .whitespaces) } ?? []
+
+        for name in names where !vary.contains(where: {
+            $0.caseInsensitiveCompare(name) == .orderedSame
+        }) {
+            vary.append(name)
+        }
+
+        response.headers[.vary] = vary.joined(separator: ", ")
+
+        return response
+    }
+
+}