Extract the SourceLanguage type to a new "Common" target

Author: d-ronnqvist

Package.swift

@@ -2,7 +2,7 @@
 /*
  This source file is part of the Swift.org open source project
 
- Copyright (c) 2021-2024 Apple Inc. and the Swift project authors
+ Copyright (c) 2021-2025 Apple Inc. and the Swift project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -43,6 +43,7 @@ let package = Package(
         .target(
             name: "SwiftDocC",
             dependencies: [
+                .target(name: "Common"),
                 .product(name: "Markdown", package: "swift-markdown"),
                 .product(name: "SymbolKit", package: "swift-docc-symbolkit"),
                 .product(name: "CLMDB", package: "swift-lmdb"),
@@ -54,6 +55,7 @@ let package = Package(
             name: "SwiftDocCTests",
             dependencies: [
                 .target(name: "SwiftDocC"),
+                .target(name: "Common"),
                 .target(name: "SwiftDocCTestUtilities"),
             ],
             resources: [
@@ -69,6 +71,7 @@ let package = Package(
             name: "SwiftDocCUtilities",
             dependencies: [
                 .target(name: "SwiftDocC"),
+                .target(name: "Common"),
                 .product(name: "NIOHTTP1", package: "swift-nio", condition: .when(platforms: [.macOS, .iOS, .linux, .android])),
                 .product(name: "ArgumentParser", package: "swift-argument-parser")
             ],
@@ -79,6 +82,7 @@ let package = Package(
             dependencies: [
                 .target(name: "SwiftDocCUtilities"),
                 .target(name: "SwiftDocC"),
+                .target(name: "Common"),
                 .target(name: "SwiftDocCTestUtilities"),
             ],
             resources: [
@@ -93,6 +97,7 @@ let package = Package(
             name: "SwiftDocCTestUtilities",
             dependencies: [
                 .target(name: "SwiftDocC"),
+                .target(name: "Common"),
                 .product(name: "SymbolKit", package: "swift-docc-symbolkit"),
             ],
             swiftSettings: swiftSettings
@@ -106,6 +111,25 @@ let package = Package(
             ],
             swiftSettings: swiftSettings
         ),
+        
+        // A few common types and core functionality that's useable by all other targets.
+        .target(
+            name: "Common",
+            dependencies: [
+                // This target shouldn't have any local dependencies so that all other targets can depend on it.
+                // We can add dependencies on SymbolKit and Markdown here but they're not needed yet.
+            ],
+            swiftSettings: swiftSettings // FIXME: Use `[.swiftLanguageMode(.v6)]` here
+        ),
+        
+        .testTarget(
+            name: "CommonTests",
+            dependencies: [
+                .target(name: "Common"),
+                .target(name: "SwiftDocCTestUtilities"),
+            ],
+            swiftSettings: swiftSettings // FIXME: Use `[.swiftLanguageMode(.v6)]` here
+        ),
 
         // Test app for SwiftDocCUtilities
         .executableTarget(

Sources/SwiftDocC/Model/SourceLanguage.swift renamed to Sources/Common/SourceLanguage.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift.org open source project
 
- Copyright (c) 2021-2023 Apple Inc. and the Swift project authors
+ Copyright (c) 2021-2025 Apple Inc. and the Swift project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -157,7 +157,9 @@ public struct SourceLanguage: Hashable, Codable, Comparable {
 
         try container.encode(self.name, forKey: SourceLanguage.CodingKeys.name)
         try container.encode(self.id, forKey: SourceLanguage.CodingKeys.id)
-        try container.encodeIfNotEmpty(self.idAliases, forKey: SourceLanguage.CodingKeys.idAliases)
+        if !self.idAliases.isEmpty {
+            try container.encode(self.idAliases, forKey: SourceLanguage.CodingKeys.idAliases)
+        }
         try container.encode(self.linkDisambiguationID, forKey: SourceLanguage.CodingKeys.linkDisambiguationID)
     }
 

Sources/SwiftDocC/Catalog Processing/GeneratedCurationWriter.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift.org open source project
 
- Copyright (c) 2024 Apple Inc. and the Swift project authors
+ Copyright (c) 2024-2025 Apple Inc. and the Swift project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -10,6 +10,7 @@
 
 public import Foundation
 import SymbolKit
+import Common
 
 /// A type that writes the auto-generated curation into documentation extension files.
 public struct GeneratedCurationWriter {

Sources/SwiftDocC/Indexing/Navigator/RenderNode+NavigatorIndex.swift

@@ -9,6 +9,7 @@
 */
 
 import Foundation
+import Common
 
 /// A language specific representation of a render node value for building a navigator index.
 protocol NavigatorIndexableRenderNodeRepresentation<Metadata> {

Sources/SwiftDocC/Infrastructure/CoverageDataEntry.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift.org open source project
 
- Copyright (c) 2021-2024 Apple Inc. and the Swift project authors
+ Copyright (c) 2021-2025 Apple Inc. and the Swift project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -10,6 +10,7 @@
 
 import Foundation
 import SymbolKit
+import Common
 
 /// `CoverageDataEntry` represents coverage data for one symbol/USR.
 public struct CoverageDataEntry: CustomStringConvertible, Codable {

Sources/SwiftDocC/Infrastructure/DocumentationContext.swift

@@ -11,6 +11,7 @@
 public import Foundation
 import Markdown
 import SymbolKit
+public import Common
 
 /// The documentation context manages the in-memory model for the built documentation.
 ///

Sources/SwiftDocC/Infrastructure/External Data/OutOfProcessReferenceResolver+DeprecatedCommunication.swift

@@ -10,6 +10,7 @@
 
 public import Foundation
 public import SymbolKit
+public import Common
 
 extension OutOfProcessReferenceResolver {
 

Sources/SwiftDocC/Infrastructure/External Data/OutOfProcessReferenceResolver.swift

@@ -10,6 +10,7 @@
 
 public import Foundation
 private import Markdown
+import Common
 
 /// A reference resolver that launches and interactively communicates with another process or service to resolve links.
 ///

Sources/SwiftDocC/Infrastructure/Link Resolution/LinkResolver+NavigatorIndex.swift

@@ -10,6 +10,7 @@
 
 import Foundation
 import SymbolKit
+import Common
 
 /// A rendering-friendly representation of a external node.
 package struct ExternalRenderNode {

Sources/SwiftDocC/Infrastructure/Link Resolution/LinkResolver.swift

@@ -9,6 +9,7 @@
 */
 
 import Foundation
+import Common
 
 /// A class that resolves documentation links by orchestrating calls to other link resolver implementations.
 public class LinkResolver {