integrate registry dependencies into dependency resolution

motivation: support registries

changes:
* create RegistryPackageContainer to handle dependencies from registry, integrated with the previously introduces registry client
* update workspace to create RegistryPackageContainer when dealing with registry dependencies
* update registry client (RegitryManager) to perform download request (buffered) when downloading the package archive
* update registry client manifest listing and handling so it supportes multi-manifest setups. simplified the client to return the manifest content instead of attempting to load it which is done in RegistryPackageContainer which has additional context
* update registry client to use Codable
* add testing infrastructure to MockWorkspace to mock registry dependencies
* add basic tests for regsitry scenarios

Author: tomerd

Sources/Basics/HTTPClient.swift

@@ -387,7 +387,11 @@ public struct HTTPClientResponse {
 
 extension HTTPClientResponse {
     public static func okay(body: String? = nil) -> HTTPClientResponse {
-        return HTTPClientResponse(statusCode: 200, body: body?.data(using: .utf8))
+        return .okay(body: body?.data(using: .utf8))
+    }
+
+    public static func okay(body: Data?) -> HTTPClientResponse {
+        return HTTPClientResponse(statusCode: 200, body: body)
     }
 
     public static func notFound(reason: String? = nil) -> HTTPClientResponse {

Sources/PackageGraph/PackageGraph+Loading.swift

@@ -247,9 +247,9 @@ private func createResolvedPackages(
                 case .remote(let url):
                     dependencyLocation = url.absoluteString
                 }
-            case .registry:
-                // FIXME
-                fatalError("registry based dependencies not implemented yet")
+            case .registry(let settings):
+                // TODO: this is
+                dependencyLocation = settings.identity.description
             }
 
             // Otherwise, look it up by its identity.

Sources/PackageLoading/ToolsVersionLoader.swift

@@ -353,9 +353,13 @@ public struct ToolsVersionLoader: ToolsVersionLoaderProtocol {
         guard let manifestContentsDecodedWithUTF8 = manifestContents.validDescription else {
             throw Error.nonUTF8EncodedManifest(path: file)
         }
-        
+
+        return try self.load(utf8String: manifestContentsDecodedWithUTF8)
+    }
+
+    public func load(utf8String: String) throws -> ToolsVersion {
         /// The manifest represented in its constituent parts.
-        let manifestComponents = ToolsVersionLoader.split(manifestContentsDecodedWithUTF8)
+        let manifestComponents = ToolsVersionLoader.split(utf8String)
         /// The Swift tools version specification represented in its constituent parts.
         let toolsVersionSpecificationComponents = manifestComponents.toolsVersionSpecificationComponents
 

Sources/PackageModel/PackageIdentity.swift

@@ -65,14 +65,14 @@ public struct PackageIdentity: CustomStringConvertible {
     }
 
     // TODO: formalize package registry identifier
-    public var scopeAndName: (Scope, Name)? {
+    public var scopeAndName: (scope: Scope, name: Name)? {
         let components = description.split(separator: ".", maxSplits: 1, omittingEmptySubsequences: true)
         guard components.count == 2,
               let scope = Scope(components.first),
               let name = Name(components.last)
-        else { return nil }
+        else { return .none }
 
-        return (scope, name)
+        return (scope: scope, name: name)
     }
 }
 

Sources/PackageRegistry/CMakeLists.txt

@@ -9,7 +9,7 @@
 add_library(PackageRegistry
   Registry.swift
   RegistryConfiguration.swift
-  RegistryManager.swift
+  RegistryClient.swift
   SourceArchiver.swift)
 target_link_libraries(PackageRegistry PUBLIC
   Basics