Refactor: Split RFC-specific initializers into separate files and rename error type

- Extract RFC 5321, 5322, and 6531 initializers to EmailAddress+RFC*.swift files
- Rename EmailAddressError to EmailAddress.Error (nested type)
- Add comprehensive tests for RFC_2822.AddrSpec conversion
- All 30 tests passing

Author: coenttb

Sources/EmailAddress/EmailAddress+RFC5321.swift

@@ -0,0 +1,29 @@
+import Foundation
+import RFC_5321
+import RFC_5322
+import RFC_6531
+
+extension EmailAddress {
+    /// Initialize from RFC5321
+    public init(rfc5321: RFC_5321.EmailAddress) throws {
+        self.rfc5321 = rfc5321
+        self.rfc5322 = try? RFC_5322.EmailAddress(
+            displayName: rfc5321.displayName,
+            localPart: .init(rfc5321.localPart.stringValue),
+            domain: .init(rfc5321.domain.name)
+        )
+        self.rfc6531 = try {
+            guard
+                let email = try? RFC_6531.EmailAddress(
+                    displayName: rfc5321.displayName,
+                    localPart: .init(rfc5321.localPart.stringValue),
+                    domain: .init(rfc5321.domain.name)
+                )
+            else {
+                throw EmailAddress.Error.conversionFailure
+            }
+            return email
+        }()
+        self.displayName = rfc5321.displayName
+    }
+}

Sources/EmailAddress/EmailAddress+RFC5322.swift

@@ -0,0 +1,25 @@
+import Foundation
+import RFC_5321
+import RFC_5322
+import RFC_6531
+
+extension EmailAddress {
+    /// Initialize from RFC5322
+    public init(rfc5322: RFC_5322.EmailAddress) throws {
+        self.rfc5321 = try? rfc5322.toRFC5321()
+        self.rfc5322 = rfc5322
+        self.rfc6531 = try {
+            guard
+                let email = try? RFC_6531.EmailAddress(
+                    displayName: rfc5322.displayName,
+                    localPart: .init(rfc5322.localPart.stringValue),
+                    domain: rfc5322.domain
+                )
+            else {
+                throw EmailAddress.Error.conversionFailure
+            }
+            return email
+        }()
+        self.displayName = rfc5322.displayName
+    }
+}

Sources/EmailAddress/EmailAddress+RFC6531.swift

@@ -0,0 +1,14 @@
+import Foundation
+import RFC_5321
+import RFC_5322
+import RFC_6531
+
+extension EmailAddress {
+    /// Initialize from RFC6531
+    public init(rfc6531: RFC_6531.EmailAddress) {
+        self.rfc5321 = try? rfc6531.toRFC5321()
+        self.rfc5322 = try? rfc6531.toRFC5322()
+        self.rfc6531 = rfc6531
+        self.displayName = rfc6531.displayName
+    }
+}

Sources/EmailAddress/EmailAddress.swift

@@ -71,55 +71,6 @@ public struct EmailAddress: Hashable, Sendable {
         )
     }
 
-    /// Initialize from RFC5321
-    public init(rfc5321: RFC_5321.EmailAddress) throws {
-        self.rfc5321 = rfc5321
-        self.rfc5322 = try? RFC_5322.EmailAddress(
-            displayName: rfc5321.displayName,
-            localPart: .init(rfc5321.localPart.stringValue),
-            domain: .init(rfc5321.domain.name)
-        )
-        self.rfc6531 = try {
-            guard
-                let email = try? RFC_6531.EmailAddress(
-                    displayName: rfc5321.displayName,
-                    localPart: .init(rfc5321.localPart.stringValue),
-                    domain: .init(rfc5321.domain.name)
-                )
-            else {
-                throw EmailAddressError.conversionFailure
-            }
-            return email
-        }()
-        self.displayName = rfc5321.displayName
-    }
-
-    /// Initialize from RFC5322
-    public init(rfc5322: RFC_5322.EmailAddress) throws {
-        self.rfc5321 = try? rfc5322.toRFC5321()
-        self.rfc5322 = rfc5322
-        self.rfc6531 = try {
-            guard
-                let email = try? RFC_6531.EmailAddress(
-                    displayName: rfc5322.displayName,
-                    localPart: .init(rfc5322.localPart.stringValue),
-                    domain: rfc5322.domain
-                )
-            else {
-                throw EmailAddressError.conversionFailure
-            }
-            return email
-        }()
-        self.displayName = rfc5322.displayName
-    }
-
-    /// Initialize from RFC6531
-    public init(rfc6531: RFC_6531.EmailAddress) {
-        self.rfc5321 = try? rfc6531.toRFC5321()
-        self.rfc5322 = try? rfc6531.toRFC5322()
-        self.rfc6531 = rfc6531
-        self.displayName = rfc6531.displayName
-    }
 }
 
 // MARK: - Properties
@@ -200,7 +151,7 @@ extension EmailAddress {
 
 // MARK: - Errors
 extension EmailAddress {
-    public enum EmailAddressError: Error, Equatable, LocalizedError {
+    public enum Error: Swift.Error, Equatable, LocalizedError {
         case conversionFailure
         case invalidFormat(description: String)
 
@@ -251,7 +202,7 @@ extension EmailAddress {
     public static func ascii(_ string: String) throws -> Self {
         let email = try Self(string)
         guard email.isASCII else {
-            throw EmailAddressError.invalidFormat(description: "Must be ASCII-only")
+            throw Error.invalidFormat(description: "Must be ASCII-only")
         }
         return email
     }

Tests/EmailAddress Tests/RFC2822ConversionTests.swift

@@ -0,0 +1,54 @@
+import Testing
+import Foundation
+@testable import EmailAddress
+import RFC_2822
+
+@Suite("RFC 2822 AddrSpec Conversion Tests")
+struct RFC2822ConversionTests {
+
+    @Test("Convert EmailAddress to RFC_2822.AddrSpec")
+    func emailAddressToAddrSpec() throws {
+        let email = try EmailAddress("[email protected]")
+        let addrSpec = try RFC_2822.AddrSpec(email)
+
+        #expect(addrSpec.localPart == "user")
+        #expect(addrSpec.domain == "example.com")
+        #expect(addrSpec.description == "[email protected]")
+    }
+
+    @Test("Convert RFC_2822.AddrSpec to EmailAddress")
+    func addrSpecToEmailAddress() throws {
+        let addrSpec = try RFC_2822.AddrSpec(localPart: "test", domain: "example.org")
+        let email = try EmailAddress(addrSpec)
+
+        #expect(email.rfc5322?.localPart.stringValue == "test")
+        #expect(email.rfc5322?.domain.name == "example.org")
+    }
+
+    @Test("Round-trip conversion EmailAddress -> AddrSpec -> EmailAddress")
+    func roundTripConversion() throws {
+        let original = try EmailAddress("[email protected]")
+        let addrSpec = try RFC_2822.AddrSpec(original)
+        let converted = try EmailAddress(addrSpec)
+
+        #expect(original == converted)
+    }
+
+    @Test("Convert EmailAddress with subdomain to RFC_2822.AddrSpec")
+    func emailWithSubdomainToAddrSpec() throws {
+        let email = try EmailAddress("[email protected]")
+        let addrSpec = try RFC_2822.AddrSpec(email)
+
+        #expect(addrSpec.localPart == "admin")
+        #expect(addrSpec.domain == "mail.example.com")
+    }
+
+    @Test("Convert EmailAddress with special characters to RFC_2822.AddrSpec")
+    func emailWithSpecialCharsToAddrSpec() throws {
+        let email = try EmailAddress("[email protected]")
+        let addrSpec = try RFC_2822.AddrSpec(email)
+
+        #expect(addrSpec.localPart == "user+tag")
+        #expect(addrSpec.domain == "example.com")
+    }
+}