Added more docs to internal types

Author: dimitribouniol

README.md

@@ -28,7 +28,7 @@ Please check the [releases](https://github.com/mochidev/swift-webpush/releases)
 ```swift
 dependencies: [
     .package(
-        url: "https://github.com/mochidev/swift-webPush.git", 
+        url: "https://github.com/mochidev/swift-webpush.git", 
         .upToNextMinor(from: "0.2.1")
     ),
 ],
@@ -180,11 +180,15 @@ The `WebPushTesting` module can be used to obtain a mocked `WebPushManager` inst
 
 ## Specifications
 
+- [RFC 7515 JSON Web Signature (JWS)](https://datatracker.ietf.org/doc/html/rfc7515)
+- [RFC 7519 JSON Web Token (JWT)](https://datatracker.ietf.org/doc/html/rfc7519)
 - [RFC 8030 Generic Event Delivery Using HTTP Push](https://datatracker.ietf.org/doc/html/rfc8030)
 - [RFC 8188 Encrypted Content-Encoding for HTTP](https://datatracker.ietf.org/doc/html/rfc8188)
 - [RFC 8291 Message Encryption for Web Push](https://datatracker.ietf.org/doc/html/rfc8291)
 - [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push](https://datatracker.ietf.org/doc/html/rfc8292)
 
+- [Push API Working Draft](https://www.w3.org/TR/push-api/)
+
 ## Contributing
 
 Contribution is welcome! Please take a look at the issues already available, or start a new discussion to propose a new feature. Although guarantees can't be made regarding feature requests, PRs that fit within the goals of the project and that have been discussed beforehand are more than welcome!

Sources/WebPush/VAPID/VAPIDKey.swift

@@ -66,7 +66,7 @@ extension VAPID.Key: Identifiable {
     ///
     /// This value can be shared as is with a subscription registration as the `applicationServerKey` key in JavaScript.
     ///
-    /// - SeeAlso: [Push API Working Draft §7.2. PushSubscriptionOptions Interface](https://www.w3.org/TR/push-api/#pushsubscriptionoptions-interface)
+    /// - SeeAlso: [Push API Working Draft §7.2. `PushSubscriptionOptions` Interface](https://www.w3.org/TR/push-api/#pushsubscriptionoptions-interface)
     public struct ID: Hashable, Comparable, Codable, Sendable, CustomStringConvertible {
         private var rawValue: String
 
@@ -93,6 +93,10 @@ extension VAPID.Key: Identifiable {
         }
     }
 
+    /// The public key component in a format suitable for user agents to consume.
+    ///
+    /// - SeeAlso: [Push API Working Draft §7.2. `PushSubscriptionOptions` Interface](https://www.w3.org/TR/push-api/#dom-pushsubscriptionoptions-applicationserverkey)
+    /// - SeeAlso: [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push §3.2. Public Key Parameter ("k")](https://datatracker.ietf.org/doc/html/rfc8292#section-3.2)
     public var id: ID {
         ID(privateKey.publicKey.x963Representation.base64URLEncodedString())
     }

Sources/WebPush/VAPID/VAPIDToken.swift

@@ -13,39 +13,62 @@ extension VAPID {
     /// An internal representation the token and authorization headers used self-identification.
     ///
     /// - SeeAlso: [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push §2. Application Server Self-Identification](https://datatracker.ietf.org/doc/html/rfc8292#section-2)
+    /// - SeeAlso: [RFC 7515 JSON Web Signature (JWS)](https://datatracker.ietf.org/doc/html/rfc7515)
+    ///- SeeAlso: [RFC 7519 JSON Web Token (JWT)](https://datatracker.ietf.org/doc/html/rfc7519)
     struct Token: Hashable, Codable, Sendable {
         enum CodingKeys: String, CodingKey {
             case audience = "aud"
             case subject = "sub"
             case expiration = "exp"
         }
 
+        /// The audience claim, which encodes the origin of the ``Subscriber/endpoint``
+        ///
+        /// - SeeAlso: ``/Foundation/URL/origin``
+        /// - SeeAlso: [RFC 7519 JSON Web Token (JWT) §4.1.3. "aud" (Audience) Claim](https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.3)
+        /// - SeeAlso: [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push §2. Application Server Self-Identification](https://datatracker.ietf.org/doc/html/rfc8292#section-2)
         var audience: String
-        var subject: VAPID.Configuration.ContactInformation
+        
+        /// The subject claim, which encodes contact information for the application server.
+        ///
+        /// - SeeAlso: [RFC 7519 JSON Web Token (JWT) §4.1.2. "sub" (Subject) Claim](https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.2)
+        /// - SeeAlso: [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push §2.1. Application Server Contact Information](https://datatracker.ietf.org/doc/html/rfc8292#section-2.1)
+        var subject: Configuration.ContactInformation
+        
+        /// The expiry claim, which encodes the number of seconds after 1970/01/01 when the token expires.
+        ///
+        /// - SeeAlso: [RFC 7519 JSON Web Token (JWT) §4.1.4. "exp" (Expiration Time) Claim](https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.4)
+        /// - SeeAlso: [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push §2. Application Server Self-Identification](https://datatracker.ietf.org/doc/html/rfc8292#section-2)
         var expiration: Int
 
+        /// The standard header including the type and algorithm.
+        ///
+        /// - SeeAlso: [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push §2. Application Server Self-Identification](https://datatracker.ietf.org/doc/html/rfc8292#section-2)
         static let jwtHeader = Array(#"{"typ":"JWT","alg":"ES256"}"#.utf8).base64URLEncodedString()
 
+        /// Initialize a token with the specified claims.
         init(
             origin: String,
-            contactInformation: VAPID.Configuration.ContactInformation,
+            contactInformation: Configuration.ContactInformation,
             expiration: Date
         ) {
             self.audience = origin
             self.subject = contactInformation
             self.expiration = Int(expiration.timeIntervalSince1970)
         }
 
+        /// Initialize a token with the specified claims.
         init(
             origin: String,
-            contactInformation: VAPID.Configuration.ContactInformation,
-            expiresIn: VAPID.Configuration.Duration
+            contactInformation: Configuration.ContactInformation,
+            expiresIn: Configuration.Duration
         ) {
             audience = origin
             subject = contactInformation
             expiration = Int(Date.now.timeIntervalSince1970) + expiresIn.seconds
         }
 
+        /// Initialize a token from a VAPID `Authorization` header's values.
         init?(token: String, key: String) {
             let components = token.split(separator: ".")
 
@@ -69,6 +92,7 @@ extension VAPID {
             self = token
         }
 
+        /// - SeeAlso: [RFC 7515 JSON Web Signature (JWS) §3. JSON Web Signature (JWS) Overview](https://datatracker.ietf.org/doc/html/rfc7515#section-3)
         func generateJWT(signedBy signingKey: some VAPIDKeyProtocol) throws -> String {
             let header = Self.jwtHeader
 
@@ -81,6 +105,9 @@ extension VAPID {
             return "\(message).\(signature)"
         }
 
+        /// Generate an `Authorization` header.
+        ///
+        /// - SeeAlso: [RFC 8292 Voluntary Application Server Identification (VAPID) for Web Push §3. VAPID Authentication Scheme](https://datatracker.ietf.org/doc/html/rfc8292#section-3)
         func generateAuthorization(signedBy signingKey: some VAPIDKeyProtocol) throws -> String {
             let token = try generateJWT(signedBy: signingKey)
             let key = signingKey.id
@@ -93,5 +120,7 @@ extension VAPID {
 protocol VAPIDKeyProtocol: Identifiable, Sendable {
     associatedtype Signature: ContiguousBytes
 
+    /// Returns a JWS signature for the message.
+    /// - SeeAlso: [RFC 7515 JSON Web Signature (JWS)](https://datatracker.ietf.org/doc/html/rfc7515)
     func signature(for message: some DataProtocol) throws -> Signature
 }