[Collections] refreshCollection should have correct source config (#3314)

Motivation:
`refreshCollection` relies on `CollectionSource` argument to provide the correct source config, but it should:
1. Check that the source exists in the config
2. Read latest source config from storage

Modifications:
Update `refreshCollection` to check that the given source exists in config file before actually doing a refresh. Also make sure that `Collection`'s `source` is current before returning it.

Author: yim-lee

Sources/PackageCollections/Model/Collection.swift

@@ -31,7 +31,7 @@ extension PackageCollectionsModel {
         public let identifier: Identifier
 
         /// Where the collection and its contents are obtained
-        public let source: Source
+        public internal(set) var source: Source
 
         /// The name of the collection
         public let name: String

Sources/PackageCollections/PackageCollections.swift

@@ -158,7 +158,17 @@ public struct PackageCollections: PackageCollectionsProtocol {
             return callback(.failure(PackageCollectionError.unsupportedPlatform))
         }
 
-        self.refreshCollectionFromSource(source: source, trustConfirmationProvider: nil, callback: callback)
+        self.storage.sources.list { result in
+            switch result {
+            case .failure(let error):
+                callback(.failure(error))
+            case .success(let sources):
+                guard let savedSource = sources.first(where: { $0 == source }) else {
+                    return callback(.failure(NotFoundError("\(source)")))
+                }
+                self.refreshCollectionFromSource(source: savedSource, trustConfirmationProvider: nil, callback: callback)
+            }
+        }
     }
 
     public func addCollection(_ source: PackageCollectionsModel.CollectionSource,
@@ -389,7 +399,7 @@ public struct PackageCollections: PackageCollectionsProtocol {
             switch result {
             case .failure(let error):
                 callback(.failure(error))
-            case .success(let collection):
+            case .success(var collection):
                 // If collection is signed and signature is valid, save to storage. `provider.get`
                 // would have failed if signature were invalid.
                 if collection.isSigned {
@@ -426,6 +436,7 @@ public struct PackageCollections: PackageCollectionsProtocol {
                             callback(.failure(error))
                         case .success:
                             if userTrusted {
+                                collection.source = source
                                 self.storage.collections.put(collection: collection, callback: callback)
                             } else {
                                 // Try to remove the untrusted collection (if previously saved) from storage before calling back

Tests/PackageCollectionsTests/PackageCollectionsTests.swift

@@ -977,6 +977,44 @@ final class PackageCollectionsTests: XCTestCase {
         XCTAssertEqual(list.count, mockCollections.count, "list count should match")
     }
 
+    func testRefreshOneTrustedUnsigned() throws {
+        try skipIfUnsupportedPlatform()
+
+        let configuration = PackageCollections.Configuration()
+        let storage = makeMockStorage()
+        defer { XCTAssertNoThrow(try storage.close()) }
+
+        let mockCollections = makeMockCollections(count: 1, signed: false)
+        let collectionProviders = [PackageCollectionsModel.CollectionSourceType.json: MockCollectionsProvider(mockCollections)]
+        let metadataProvider = MockMetadataProvider([:])
+        let packageCollections = PackageCollections(configuration: configuration, storage: storage, collectionProviders: collectionProviders, metadataProvider: metadataProvider)
+
+        // User trusted
+        let collection = try tsc_await { callback in packageCollections.addCollection(mockCollections[0].source, order: nil, trustConfirmationProvider: { _, cb in cb(true) }, callback: callback) }
+        XCTAssertEqual(true, collection.source.isTrusted) // isTrusted is nil-able
+
+        // `isTrusted` should be true so refreshCollection should succeed
+        XCTAssertNoThrow(try tsc_await { callback in packageCollections.refreshCollection(collection.source, callback: callback) })
+    }
+
+    func testRefreshOneNotFound() throws {
+        try skipIfUnsupportedPlatform()
+
+        let configuration = PackageCollections.Configuration()
+        let storage = makeMockStorage()
+        defer { XCTAssertNoThrow(try storage.close()) }
+
+        let mockCollections = makeMockCollections(count: 1, signed: false)
+        let collectionProviders = [PackageCollectionsModel.CollectionSourceType.json: MockCollectionsProvider(mockCollections)]
+        let metadataProvider = MockMetadataProvider([:])
+        let packageCollections = PackageCollections(configuration: configuration, storage: storage, collectionProviders: collectionProviders, metadataProvider: metadataProvider)
+
+        // Don't add collection so it's not found in the config
+        XCTAssertThrowsError(try tsc_await { callback in packageCollections.refreshCollection(mockCollections[0].source, callback: callback) }, "expected error") { error in
+            XCTAssert(error is NotFoundError)
+        }
+    }
+
     func testListTargets() throws {
         try skipIfUnsupportedPlatform()