Annotate enums as frozen/nonexhaustive

Co-authored-by: Alex Hoppen <[email protected]>

Author: owenv

CONTRIBUTING.md

@@ -28,3 +28,9 @@ See the [dedicated section][section] on the Swift project website.
 After you opened your PR, a maintainer will review it and test your changes in CI (*Continuous Integration*) by adding a `@swift-ci Please test` comment on the pull request. Once your PR is approved and CI has passed, the maintainer will merge your pull request.
 
 Only contributors with [commit access](https://www.swift.org/contributing/#commit-access) are able to approve pull requests and trigger CI.
+
+## API Design
+
+### Public `enum`s
+
+Enums should generally be marked as `@frozen` or `@nonexhaustive` to allow consistent behavior when switching over them in library-evolution and non-library-evolution builds. The default should be `@frozen` unless we expect to extend the enum without adopting a new LSP or BSP version, eg. because the type is part of an LSP extension. We do not need to anticipate the LSP/BSP specification changing since we plan to release a new major version of swift-tools-protocols when it gets updated to a new LSP or BSP specification version. Custom `CodingKey` enums should always be marked as `@nonexhaustive` because we want to be able to add new members to structs.

Sources/BuildServerProtocol/Messages/BuildTargetSourcesRequest.swift

@@ -94,7 +94,7 @@ public struct SourceItem: Codable, Hashable, Sendable {
   }
 }
 
-public enum SourceItemKind: Int, Codable, Hashable, Sendable {
+@frozen public enum SourceItemKind: Int, Codable, Hashable, Sendable {
   /// The source item references a normal file.
   case file = 1
 
@@ -120,7 +120,7 @@ public struct SourceItemDataKind: RawRepresentable, Codable, Hashable, Sendable
 
 /// **(BSP Extension)**
 
-public enum SourceKitSourceItemKind: String, Codable {
+/*@nonexhaustive*/ public enum SourceKitSourceItemKind: String, Codable {
   /// A source file that belongs to the target
   case source = "source"
 

Sources/BuildServerProtocol/Messages/OnBuildLogMessageNotification.swift

@@ -50,7 +50,7 @@ public struct OnBuildLogMessageNotification: BSPNotification {
   }
 }
 
-public enum StructuredLogKind: Codable, Hashable, Sendable {
+@frozen public enum StructuredLogKind: Codable, Hashable, Sendable {
   case begin(StructuredLogBegin)
   case report(StructuredLogReport)
   case end(StructuredLogEnd)

Sources/BuildServerProtocol/Messages/OnBuildTargetDidChangeNotification.swift

@@ -53,7 +53,7 @@ public struct BuildTargetEvent: Codable, Hashable, Sendable {
   }
 }
 
-public enum BuildTargetEventKind: Int, Codable, Hashable, Sendable {
+@frozen public enum BuildTargetEventKind: Int, Codable, Hashable, Sendable {
   /// The build target is new.
   case created = 1
 

Sources/BuildServerProtocol/Messages/RegisterForChangeNotifications.swift

@@ -36,7 +36,7 @@ public struct RegisterForChanges: BSPRequest {
   }
 }
 
-public enum RegisterAction: String, Hashable, Codable, Sendable {
+@frozen public enum RegisterAction: String, Hashable, Codable, Sendable {
   case register = "register"
   case unregister = "unregister"
 }

Sources/BuildServerProtocol/Messages/TaskFinishNotification.swift

@@ -165,7 +165,7 @@ public struct TestFinishData: Codable, Hashable, Sendable {
 
 }
 
-public enum TestStatus: Int, Codable, Hashable, Sendable {
+@frozen public enum TestStatus: Int, Codable, Hashable, Sendable {
   /// The test passed successfully.
   case passed = 1
 

Sources/BuildServerProtocol/SupportTypes/MessageType.swift

@@ -12,7 +12,7 @@
 
 import LanguageServerProtocol
 
-public enum MessageType: Int, Sendable, Codable {
+@frozen public enum MessageType: Int, Sendable, Codable {
   /// An error message.
   case error = 1
 

Sources/BuildServerProtocol/SupportTypes/StatusCode.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-public enum StatusCode: Int, Codable, Hashable, Sendable {
+@frozen public enum StatusCode: Int, Codable, Hashable, Sendable {
   /// Execution was successful.
   case ok = 1
 

Sources/LanguageServerProtocol/Notifications/LogMessageNotification.swift

@@ -44,7 +44,7 @@ public struct LogMessageNotification: LSPNotification, Hashable {
   }
 }
 
-public enum StructuredLogKind: Codable, Hashable, Sendable {
+@frozen public enum StructuredLogKind: Codable, Hashable, Sendable {
   case begin(StructuredLogBegin)
   case report(StructuredLogReport)
   case end(StructuredLogEnd)

Sources/LanguageServerProtocol/Notifications/WorkDoneProgress.swift

@@ -25,7 +25,7 @@ public struct WorkDoneProgress: LSPNotification, Hashable {
   }
 }
 
-public enum WorkDoneProgressKind: Codable, Hashable, Sendable {
+@frozen public enum WorkDoneProgressKind: Codable, Hashable, Sendable {
   case begin(WorkDoneProgressBegin)
   case report(WorkDoneProgressReport)
   case end(WorkDoneProgressEnd)