tests: Mechanically convert to swift-testing (#45)

Motivation
----------

swift-testing offers a more convenient way to write test cases.   For
instance, it makes table-driven tests much easier to write than XCTest.

Modifications
-------------

This commit rewrites the existing XCTest test cases to use
swift-testing. It is a mechanical translation using the rules in:

   https://developer.apple.com/documentation/testing/migratingfromxctest

It does not try to adapt the style of the tests to `swift-testing`.

Result
------

The tests run using `swift-testing` with minimal changes. A future
change will adapt them to make better use of the new framework's
facilities.

One immediate improvement is that the `swift-testing` tests can be run
with the OSS Swift toolchain on macOS. `XCTests` cannot, because the
framework is not included in the OSS toolchain.

Test Plan
---------

All tests continue to pass.

Author: euanh

Tests/ContainerRegistryTests/AuthTests.swift

@@ -12,79 +12,87 @@
 //
 //===----------------------------------------------------------------------===//
 
-import Foundation
 import Basics
-import XCTest
+import Foundation
+import Testing
 
-class AuthTests: XCTestCase, @unchecked Sendable {
+struct AuthTests {
     // SwiftPM's NetrcAuthorizationProvider does not throw an error if the .netrc file
     // does not exist.   For simplicity the local vendored version does the same.
-    func testNonexistentNetrc() async throws {
+    @Test func testNonexistentNetrc() async throws {
         // Construct a URL to a nonexistent file in the bundle directory
         let netrcURL = Bundle.module.resourceURL!.appendingPathComponent("netrc.nonexistent")
-        XCTAssertFalse(FileManager.default.fileExists(atPath: netrcURL.path))
+        #expect(!FileManager.default.fileExists(atPath: netrcURL.path))
 
         let authProvider = try NetrcAuthorizationProvider(netrcURL)
-        XCTAssertNil(authProvider.authentication(for: URL(string: "https://hub.example.com")!))
+        #expect(authProvider.authentication(for: URL(string: "https://hub.example.com")!) == nil)
     }
 
-    func testEmptyNetrc() async throws {
+    @Test func testEmptyNetrc() async throws {
         let netrcURL = Bundle.module.url(forResource: "netrc", withExtension: "empty")!
         let authProvider = try NetrcAuthorizationProvider(netrcURL)
-        XCTAssertNil(authProvider.authentication(for: URL(string: "https://hub.example.com")!))
+        #expect(authProvider.authentication(for: URL(string: "https://hub.example.com")!) == nil)
     }
 
-    func testBasicNetrc() async throws {
+    @Test func testBasicNetrc() async throws {
         let netrcURL = Bundle.module.url(forResource: "netrc", withExtension: "basic")!
         let authProvider = try NetrcAuthorizationProvider(netrcURL)
-        XCTAssertNil(authProvider.authentication(for: URL(string: "https://nothing.example.com")!))
+        #expect(authProvider.authentication(for: URL(string: "https://nothing.example.com")!) == nil)
 
         guard let (user, password) = authProvider.authentication(for: URL(string: "https://hub.example.com")!) else {
-            return XCTFail("Expected to find a username and password")
+            Issue.record("Expected to find a username and password")
+            return
         }
-        XCTAssertEqual(user, "swift")
-        XCTAssertEqual(password, "password")
+        #expect(user == "swift")
+        #expect(password == "password")
     }
 
     // The default entry is used if no specific entry matches
-    func testComplexNetrcWithDefault() async throws {
+    @Test func testComplexNetrcWithDefault() async throws {
         let netrcURL = Bundle.module.url(forResource: "netrc", withExtension: "default")!
         let authProvider = try NetrcAuthorizationProvider(netrcURL)
 
         guard let (user, password) = authProvider.authentication(for: URL(string: "https://nothing.example.com")!)
-        else { return XCTFail("Expected to find a username and password") }
-        XCTAssertEqual(user, "defaultlogin")
-        XCTAssertEqual(password, "defaultpassword")
+        else {
+            Issue.record("Expected to find a username and password")
+            return
+        }
+        #expect(user == "defaultlogin")
+        #expect(password == "defaultpassword")
     }
 
     // The default entry must be last in the file
-    func testComplexNetrcWithInvalidDefault() async throws {
+    @Test func testComplexNetrcWithInvalidDefault() async throws {
         let netrcURL = Bundle.module.url(forResource: "netrc", withExtension: "invaliddefault")!
-        XCTAssertThrowsError(try NetrcAuthorizationProvider(netrcURL)) { error in
-            XCTAssertEqual(error as! NetrcError, NetrcError.invalidDefaultMachinePosition)
+        #expect { try NetrcAuthorizationProvider(netrcURL) } throws: { error in
+            error as! NetrcError == NetrcError.invalidDefaultMachinePosition
         }
     }
 
     // If there are multiple entries for the same host, the last one wins
-    func testComplexNetrcOverriddenEntry() async throws {
+    @Test func testComplexNetrcOverriddenEntry() async throws {
         let netrcURL = Bundle.module.url(forResource: "netrc", withExtension: "default")!
         let authProvider = try NetrcAuthorizationProvider(netrcURL)
 
         guard let (user, password) = authProvider.authentication(for: URL(string: "https://hub.example.com")!) else {
-            return XCTFail("Expected to find a username and password")
+            Issue.record("Expected to find a username and password")
+            return
         }
-        XCTAssertEqual(user, "swift2")
-        XCTAssertEqual(password, "password2")
+        #expect(user == "swift2")
+        #expect(password == "password2")
     }
 
     // A singleton entry in a netrc file with defaults and overriden entries continues to work as in the simple case
-    func testComplexNetrcSingletonEntry() async throws {
+    @Test func testComplexNetrcSingletonEntry() async throws {
         let netrcURL = Bundle.module.url(forResource: "netrc", withExtension: "default")!
         let authProvider = try NetrcAuthorizationProvider(netrcURL)
 
         guard let (user, password) = authProvider.authentication(for: URL(string: "https://another.example.com")!)
-        else { return XCTFail("Expected to find a username and password") }
-        XCTAssertEqual(user, "anotherlogin")
-        XCTAssertEqual(password, "anotherpassword")
+        else {
+            Issue.record("Expected to find a username and password")
+            return
+        }
+        #expect(user == "anotherlogin")
+        #expect(password == "anotherpassword")
     }
 }

Tests/ContainerRegistryTests/ImageReferenceTests.swift

@@ -13,7 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 @testable import ContainerRegistry
-import XCTest
+import Testing
 
 struct ReferenceTest {
     var reference: String
@@ -26,7 +26,7 @@ struct ReferenceTestCase {
     var expected: ImageReference?
 }
 
-class ReferenceTests: XCTestCase {
+struct ReferenceTests {
     let tests = [
         // A reference which does not contain a '/' is always interpreted as a repository name
         // in the default registry.
@@ -106,60 +106,59 @@ class ReferenceTests: XCTestCase {
         ),
     ]
 
-    func testReferences() throws {
+    @Test func testReferences() throws {
         for test in tests {
             let parsed = try! ImageReference(fromString: test.reference, defaultRegistry: "default")
-            XCTAssertEqual(
-                parsed,
-                test.expected,
+            #expect(
+                parsed == test.expected,
                 "\(String(reflecting: parsed)) is not equal to \(String(reflecting: test.expected))"
             )
         }
     }
 
-    func testLibraryReferences() throws {
+    @Test func testLibraryReferences() throws {
         // docker.io is a special case, as references such as "swift:slim" with no registry component are translated to "docker.io/library/swift:slim"
         // Verified against the behaviour of the docker CLI client
 
         // Fully-qualified name splits as usual
-        XCTAssertEqual(
-            try! ImageReference(fromString: "docker.io/library/swift:slim", defaultRegistry: "docker.io"),
-            ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
+        #expect(
+            try! ImageReference(fromString: "docker.io/library/swift:slim", defaultRegistry: "docker.io")
+                == ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
         )
 
         // A repository with no '/' part is assumed to be `library`
-        XCTAssertEqual(
-            try! ImageReference(fromString: "docker.io/swift:slim", defaultRegistry: "docker.io"),
-            ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
+        #expect(
+            try! ImageReference(fromString: "docker.io/swift:slim", defaultRegistry: "docker.io")
+                == ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
         )
 
         // Parsing with 'docker.io' as default registry is the same as the fully qualified case
-        XCTAssertEqual(
-            try! ImageReference(fromString: "library/swift:slim", defaultRegistry: "docker.io"),
-            ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
+        #expect(
+            try! ImageReference(fromString: "library/swift:slim", defaultRegistry: "docker.io")
+                == ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
         )
 
         // Bare image name with no registry or repository is interpreted as being in docker.io/library when default is docker.io
-        XCTAssertEqual(
-            try! ImageReference(fromString: "swift:slim", defaultRegistry: "docker.io"),
-            ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
+        #expect(
+            try! ImageReference(fromString: "swift:slim", defaultRegistry: "docker.io")
+                == ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "slim")
         )
 
         // The minimum reference to a library image.   No tag implies `latest`
-        XCTAssertEqual(
-            try! ImageReference(fromString: "swift", defaultRegistry: "docker.io"),
-            ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "latest")
+        #expect(
+            try! ImageReference(fromString: "swift", defaultRegistry: "docker.io")
+                == ImageReference(registry: "index.docker.io", repository: "library/swift", reference: "latest")
         )
 
         // If the registry is not docker.io, the special case logic for `library` does not apply
-        XCTAssertEqual(
-            try! ImageReference(fromString: "localhost:5000/swift", defaultRegistry: "docker.io"),
-            ImageReference(registry: "localhost:5000", repository: "swift", reference: "latest")
+        #expect(
+            try! ImageReference(fromString: "localhost:5000/swift", defaultRegistry: "docker.io")
+                == ImageReference(registry: "localhost:5000", repository: "swift", reference: "latest")
         )
 
-        XCTAssertEqual(
-            try! ImageReference(fromString: "swift", defaultRegistry: "localhost:5000"),
-            ImageReference(registry: "localhost:5000", repository: "swift", reference: "latest")
+        #expect(
+            try! ImageReference(fromString: "swift", defaultRegistry: "localhost:5000")
+                == ImageReference(registry: "localhost:5000", repository: "swift", reference: "latest")
         )
     }
 }

Tests/ContainerRegistryTests/SmokeTests.swift

@@ -14,24 +14,23 @@
 
 import Foundation
 import ContainerRegistry
-import XCTest
+import Testing
 
-class SmokeTests: XCTestCase, @unchecked Sendable {
+struct SmokeTests {
     // These are basic tests to exercise the main registry operations.
     // The tests assume that a fresh, empty registry instance is available at
     // http://$REGISTRY_HOST:$REGISTRY_PORT
 
-    var client: RegistryClient!
+    var client: RegistryClient
     let registryHost = ProcessInfo.processInfo.environment["REGISTRY_HOST"] ?? "localhost"
     let registryPort = ProcessInfo.processInfo.environment["REGISTRY_PORT"] ?? "5000"
 
     /// Registry client fixture created for each test
-    override func setUp() async throws {
-        try await super.setUp()
+    init() async throws {
         client = try await RegistryClient(registry: "\(registryHost):\(registryPort)", insecure: true)
     }
 
-    func testGetTags() async throws {
+    @Test func testGetTags() async throws {
         let repository = "testgettags"
 
         // registry:2 does not validate the contents of the config or image blobs
@@ -45,7 +44,7 @@ class SmokeTests: XCTestCase, @unchecked Sendable {
         // Initially there will be no tags
         do {
             _ = try await client.getTags(repository: repository)
-            XCTFail("Getting tags for an untagged blob should have thrown an error")
+            Issue.record("Getting tags for an untagged blob should have thrown an error")
         } catch {
             // Expect to receive an error
         }
@@ -61,7 +60,7 @@ class SmokeTests: XCTestCase, @unchecked Sendable {
         // After setting a tag, we should be able to retrieve it
         let _ = try await client.putManifest(repository: repository, reference: "latest", manifest: test_manifest)
         let firstTag = try await client.getTags(repository: repository).tags.sorted()
-        XCTAssertEqual(firstTag, ["latest"])
+        #expect(firstTag == ["latest"])
 
         // After setting another tag, the original tag should still exist
         let _ = try await client.putManifest(
@@ -70,47 +69,47 @@ class SmokeTests: XCTestCase, @unchecked Sendable {
             manifest: test_manifest
         )
         let secondTag = try await client.getTags(repository: repository)
-        XCTAssertEqual(secondTag.tags.sorted(), ["additional_tag", "latest"].sorted())
+        #expect(secondTag.tags.sorted() == ["additional_tag", "latest"].sorted())
     }
 
-    func testGetNonexistentBlob() async throws {
+    @Test func testGetNonexistentBlob() async throws {
         let repository = "testgetnonexistentblob"
 
         do {
             let _ = try await client.getBlob(
                 repository: repository,
                 digest: "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
             )
-            XCTFail("should have thrown")
+            Issue.record("should have thrown")
         } catch {}
     }
 
-    func testCheckNonexistentBlob() async throws {
+    @Test func testCheckNonexistentBlob() async throws {
         let repository = "testchecknonexistentblob"
 
         let exists = try await client.blobExists(
             repository: repository,
             digest: "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
         )
-        XCTAssertFalse(exists)
+        #expect(!exists)
     }
 
-    func testPutAndGetBlob() async throws {
+    @Test func testPutAndGetBlob() async throws {
         let repository = "testputandgetblob"  // repository name must be lowercase
 
         let blob_data = "test".data(using: .utf8)!
 
         let descriptor = try await client.putBlob(repository: repository, data: blob_data)
-        XCTAssertEqual(descriptor.digest, "sha256:9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08")
+        #expect(descriptor.digest == "sha256:9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08")
 
         let exists = try await client.blobExists(repository: repository, digest: descriptor.digest)
-        XCTAssertTrue(exists)
+        #expect(exists)
 
         let blob = try await client.getBlob(repository: repository, digest: descriptor.digest)
-        XCTAssertEqual(blob, blob_data)
+        #expect(blob == blob_data)
     }
 
-    func testPutAndGetTaggedManifest() async throws {
+    @Test func testPutAndGetTaggedManifest() async throws {
         let repository = "testputandgettaggedmanifest"  // repository name must be lowercase
 
         // registry:2 does not validate the contents of the config or image blobs
@@ -139,13 +138,13 @@ class SmokeTests: XCTestCase, @unchecked Sendable {
         let _ = try await client.putManifest(repository: repository, reference: "latest", manifest: test_manifest)
 
         let manifest = try await client.getManifest(repository: repository, reference: "latest")
-        XCTAssertEqual(manifest.schemaVersion, 2)
-        XCTAssertEqual(manifest.config.mediaType, "application/vnd.docker.container.image.v1+json")
-        XCTAssertEqual(manifest.layers.count, 1)
-        XCTAssertEqual(manifest.layers[0].mediaType, "application/vnd.docker.image.rootfs.diff.tar.gzip")
+        #expect(manifest.schemaVersion == 2)
+        #expect(manifest.config.mediaType == "application/vnd.docker.container.image.v1+json")
+        #expect(manifest.layers.count == 1)
+        #expect(manifest.layers[0].mediaType == "application/vnd.docker.image.rootfs.diff.tar.gzip")
     }
 
-    func testPutAndGetAnonymousManifest() async throws {
+    @Test func testPutAndGetAnonymousManifest() async throws {
         let repository = "testputandgetanonymousmanifest"  // repository name must be lowercase
 
         // registry:2 does not validate the contents of the config or image blobs
@@ -178,13 +177,13 @@ class SmokeTests: XCTestCase, @unchecked Sendable {
         )
 
         let manifest = try await client.getManifest(repository: repository, reference: test_manifest.digest)
-        XCTAssertEqual(manifest.schemaVersion, 2)
-        XCTAssertEqual(manifest.config.mediaType, "application/vnd.docker.container.image.v1+json")
-        XCTAssertEqual(manifest.layers.count, 1)
-        XCTAssertEqual(manifest.layers[0].mediaType, "application/vnd.docker.image.rootfs.diff.tar.gzip")
+        #expect(manifest.schemaVersion == 2)
+        #expect(manifest.config.mediaType == "application/vnd.docker.container.image.v1+json")
+        #expect(manifest.layers.count == 1)
+        #expect(manifest.layers[0].mediaType == "application/vnd.docker.image.rootfs.diff.tar.gzip")
     }
 
-    func testPutAndGetImageConfiguration() async throws {
+    @Test func testPutAndGetImageConfiguration() async throws {
         let repository = "testputandgetimageconfiguration"  // repository name must be lowercase
 
         let configuration = ImageConfiguration(
@@ -205,6 +204,6 @@ class SmokeTests: XCTestCase, @unchecked Sendable {
             digest: config_descriptor.digest
         )
 
-        XCTAssertEqual(configuration, downloaded)
+        #expect(configuration == downloaded)
     }
 }