Localizable macro

Sources/LocalizableMacros/LocalizableDiagnostic.swift

@@ -0,0 +1,23 @@
+import SwiftSyntax
+import SwiftDiagnostics
+
+enum LocalizableDiagnostic {
+    case enumRequired
+}
+
+extension LocalizableDiagnostic: DiagnosticMessage {
+    var message: String {
+        switch self {
+        case .enumRequired:
+            "The @Localizable macro requires a nested enum with localization keys."
+        }
+    }
+    
+    var diagnosticID: MessageID {
+        .init(domain: "LocalizableMacro", id: "\(self)")
+    }
+    
+    var severity: DiagnosticSeverity {
+        .error
+    }
+}