[CI] Migrate to GitHub Actions (apple#57)

.github/workflows/main.yml

@@ -0,0 +1,18 @@
+name: Main
+
+on:
+  push:
+    branches: [main]
+  schedule:
+    - cron: "0 8,20 * * *"
+
+jobs:
+  unit-tests:
+    name: Unit tests
+    uses: apple/swift-nio/.github/workflows/unit_tests.yml@main
+    with:
+      linux_5_9_arguments_override: "--explicit-target-dependency-import-check error"
+      linux_5_10_arguments_override: "--explicit-target-dependency-import-check error"
+      linux_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable -Xswiftc -warnings-as-errors"
+      linux_nightly_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_nightly_main_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"

.github/workflows/pull_request.yml

@@ -0,0 +1,26 @@
+name: PR
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize]
+
+jobs:
+  soundness:
+    name: Soundness
+    uses: swiftlang/github-workflows/.github/workflows/soundness.yml@main
+    with:
+      license_header_check_project_name: "SwiftServiceDiscovery"
+
+  unit-tests:
+    name: Unit tests
+    uses: apple/swift-nio/.github/workflows/unit_tests.yml@main
+    with:
+      linux_5_9_arguments_override: "--explicit-target-dependency-import-check error"
+      linux_5_10_arguments_override: "--explicit-target-dependency-import-check error"
+      linux_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable -Xswiftc -warnings-as-errors"
+      linux_nightly_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+      linux_nightly_main_enabled: false
+
+  cxx-interop:
+    name: Cxx interop
+    uses: apple/swift-nio/.github/workflows/cxx_interop.yml@main

.github/workflows/pull_request_label.yml

@@ -0,0 +1,18 @@
+name: PR label
+
+on:
+  pull_request:
+    types: [labeled, unlabeled, opened, reopened, synchronize]
+
+jobs:
+  semver-label-check:
+    name: Semantic Version label check
+    runs-on: ubuntu-latest
+    timeout-minutes: 1
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Check for Semantic Version label
+        uses: apple/swift-nio/.github/actions/pull_request_semver_label_checker@main

.licenseignore

@@ -0,0 +1,9 @@
+.gitignore
+.licenseignore
+.swiftformatignore
+.spi.yml
+.swift-format
+.github/
+**.md
+**.txt
+**Package.swift

.swift-format

@@ -0,0 +1,61 @@
+{
+  "fileScopedDeclarationPrivacy" : {
+    "accessLevel" : "private"
+  },
+  "indentation" : {
+    "spaces" : 4
+  },
+  "indentConditionalCompilationBlocks" : false,
+  "indentSwitchCaseLabels" : false,
+  "lineBreakAroundMultilineExpressionChainComponents" : true,
+  "lineBreakBeforeControlFlowKeywords" : false,
+  "lineBreakBeforeEachArgument" : true,
+  "lineBreakBeforeEachGenericRequirement" : true,
+  "lineLength" : 120,
+  "maximumBlankLines" : 1,
+  "prioritizeKeepingFunctionOutputTogether" : false,
+  "respectsExistingLineBreaks" : false,
+  "rules" : {
+    "AllPublicDeclarationsHaveDocumentation" : true,
+    "AlwaysUseLowerCamelCase" : false,
+    "AlwaysUseLiteralForEmptyCollectionInit" : true,
+    "AmbiguousTrailingClosureOverload" : true,
+    "BeginDocumentationCommentWithOneLineSummary" : false,
+    "DoNotUseSemicolons" : true,
+    "DontRepeatTypeInStaticProperties" : false,
+    "FileScopedDeclarationPrivacy" : true,
+    "FullyIndirectEnum" : true,
+    "GroupNumericLiterals" : true,
+    "IdentifiersMustBeASCII" : true,
+    "NeverForceUnwrap" : false,
+    "NeverUseForceTry" : false,
+    "NeverUseImplicitlyUnwrappedOptionals" : false,
+    "NoAccessLevelOnExtensionDeclaration" : false,
+    "NoAssignmentInExpressions" : true,
+    "NoBlockComments" : true,
+    "NoCasesWithOnlyFallthrough" : true,
+    "NoEmptyTrailingClosureParentheses" : true,
+    "NoLabelsInCasePatterns" : false,
+    "NoLeadingUnderscores" : false,
+    "NoParensAroundConditions" : true,
+    "NoVoidReturnOnFunctionSignature" : true,
+    "OmitExplicitReturns" : true,
+    "OneCasePerLine" : true,
+    "OneVariableDeclarationPerLine" : true,
+    "OnlyOneTrailingClosureArgument" : true,
+    "OrderedImports" : false,
+    "ReplaceForEachWithForLoop" : true,
+    "ReturnVoidInsteadOfEmptyTuple" : true,
+    "UseEarlyExits" : false,
+    "UseLetInEveryBoundCaseVariable" : false,
+    "UseShorthandTypeNames" : true,
+    "UseSingleLinePropertyGetter" : false,
+    "UseSynthesizedInitializer" : true,
+    "UseTripleSlashForDocumentationComments" : true,
+    "UseWhereClausesInForLoops" : false,
+    "ValidateDocumentationComments" : true
+  },
+  "spacesAroundRangeFormationOperators" : false,
+  "tabWidth" : 8,
+  "version" : 1
+}

CONTRIBUTING.md

@@ -57,17 +57,45 @@ A good SwiftServiceDiscovery patch is:
 3. Documented, adding API documentation as needed to cover new functions and properties.
 4. Accompanied by a great commit message, using our commit message template.
 
-### Commit Message Template
+### Run CI checks locally
 
-We require that your commit messages match our template. The easiest way to do that is to get git to help you by explicitly using the template. To do that, `cd` to the root of our repository and run:
+You can run the Github Actions workflows locally using
+[act](https://github.com/nektos/act). To run all the jobs that run on a pull
+request, use the following command:
 
-    git config commit.template dev/git.commit.template
+```
+% act pull_request
+```
+
+To run just a single job, use `workflow_call -j <job>`, and specify the inputs
+the job expects. For example, to run just shellcheck:
+
+```
+% act workflow_call -j soundness --input shell_check_enabled=true
+```
+
+To bind-mount the working directory to the container, rather than a copy, use
+`--bind`. For example, to run just the formatting, and have the results
+reflected in your working directory:
+
+```
+% act --bind workflow_call -j soundness --input format_check_enabled=true
+```
+
+If you'd like `act` to always run with certain flags, these can be be placed in
+an `.actrc` file either in the current working directory or your home
+directory, for example:
+
+```
+--container-architecture=linux/amd64
+--remote-name upstream
+--action-offline-mode
+```
 
 ### Make sure Tests work on Linux
 
 SwiftServiceDiscovery uses XCTest to run tests on both macOS and Linux.
 
-
 ## How to contribute your work
 
 Please open a pull request at https://github.com/apple/swift-service-discovery. Make sure the CI passes, and then wait for code review.

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.6
+// swift-tools-version:5.9
 
 //===----------------------------------------------------------------------===//
 //
@@ -18,19 +18,18 @@ import PackageDescription
 
 let package = Package(
     name: "swift-service-discovery",
-    products: [
-        .library(name: "ServiceDiscovery", targets: ["ServiceDiscovery"]),
-    ],
+    products: [.library(name: "ServiceDiscovery", targets: ["ServiceDiscovery"])],
     dependencies: [
         .package(url: "https://github.com/apple/swift-atomics", from: "1.0.2"),
         .package(url: "https://github.com/apple/swift-log", from: "1.2.0"),
-        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
     ],
     targets: [
-        .target(name: "ServiceDiscovery", dependencies: [
-            .product(name: "Atomics", package: "swift-atomics"),
-            .product(name: "Logging", package: "swift-log"),
-        ]),
+        .target(
+            name: "ServiceDiscovery",
+            dependencies: [
+                .product(name: "Atomics", package: "swift-atomics"), .product(name: "Logging", package: "swift-log"),
+            ]
+        ),
 
         .testTarget(name: "ServiceDiscoveryTests", dependencies: ["ServiceDiscovery"]),
     ]

README.md

@@ -113,7 +113,7 @@ let serviceDiscovery = InMemoryServiceDiscovery(configuration: configuration)
 To add a dependency on the API package, you need to declare it in your `Package.swift`:
 
 ```swift
-.package(url: "https://github.com/apple/swift-service-discovery.git", from: "0.1.0"),
+.package(url: "https://github.com/apple/swift-service-discovery.git", from: "1.3.0"),
 ```
 
 and to your library target, add "ServiceDiscovery" to your dependencies:

Sources/ServiceDiscovery/FilterInstanceServiceDiscovery.swift

@@ -14,6 +14,7 @@
 
 import Dispatch
 
+/// A service discovery implementation that filters instances using a predicate.
 public final class FilterInstanceServiceDiscovery<BaseDiscovery: ServiceDiscovery> {
     typealias Predicate = (BaseDiscovery.Instance) throws -> Bool
 
@@ -28,32 +29,60 @@ public final class FilterInstanceServiceDiscovery<BaseDiscovery: ServiceDiscover
 
 extension FilterInstanceServiceDiscovery: ServiceDiscovery {
     /// Default timeout for lookup.
-    public var defaultLookupTimeout: DispatchTimeInterval {
-        self.originalSD.defaultLookupTimeout
-    }
+    public var defaultLookupTimeout: DispatchTimeInterval { self.originalSD.defaultLookupTimeout }
 
-    public func lookup(_ service: BaseDiscovery.Service, deadline: DispatchTime?, callback: @escaping (Result<[BaseDiscovery.Instance], Error>) -> Void) {
-        self.originalSD.lookup(service, deadline: deadline) { result in callback(self.transform(result)) }
-    }
+    /// Performs a lookup for the given service's instances. The result will be sent to `callback`.
+    ///
+    /// ``defaultLookupTimeout`` will be used to compute `deadline` in case one is not specified.
+    ///
+    /// ### Threading
+    ///
+    /// `callback` may be invoked on arbitrary threads, as determined by implementation.
+    ///
+    /// - Parameters:
+    ///   - service: The service to lookup
+    ///   - deadline: Lookup is considered to have timed out if it does not complete by this time
+    ///   - callback: The closure to receive lookup result
+    public func lookup(
+        _ service: BaseDiscovery.Service,
+        deadline: DispatchTime?,
+        callback: @escaping (Result<[BaseDiscovery.Instance], Error>) -> Void
+    ) { self.originalSD.lookup(service, deadline: deadline) { result in callback(self.transform(result)) } }
 
-    public func subscribe(to service: BaseDiscovery.Service, onNext nextResultHandler: @escaping (Result<[BaseDiscovery.Instance], Error>) -> Void, onComplete completionHandler: @escaping (CompletionReason) -> Void) -> CancellationToken {
+    /// Subscribes to receive a service's instances whenever they change.
+    ///
+    /// The service's current list of instances will be sent to `nextResultHandler` when this method is first called. Subsequently,
+    /// `nextResultHandler` will only be invoked when the `service`'s instances change.
+    ///
+    /// ### Threading
+    ///
+    /// `nextResultHandler` and `completionHandler` may be invoked on arbitrary threads, as determined by implementation.
+    ///
+    /// - Parameters:
+    ///   - service: The service to subscribe to
+    ///   - nextResultHandler: The closure to receive update result
+    ///   - completionHandler: The closure to invoke when the subscription completes (e.g., when the `ServiceDiscovery` instance exits, etc.),
+    ///                 including cancellation requested through `CancellationToken`.
+    ///
+    /// -  Returns: A ``CancellationToken`` instance that can be used to cancel the subscription in the future.
+    public func subscribe(
+        to service: BaseDiscovery.Service,
+        onNext nextResultHandler: @escaping (Result<[BaseDiscovery.Instance], Error>) -> Void,
+        onComplete completionHandler: @escaping (CompletionReason) -> Void
+    ) -> CancellationToken {
         self.originalSD.subscribe(
             to: service,
             onNext: { result in nextResultHandler(self.transform(result)) },
             onComplete: completionHandler
         )
     }
 
-    private func transform(_ result: Result<[BaseDiscovery.Instance], Error>) -> Result<[BaseDiscovery.Instance], Error> {
+    private func transform(_ result: Result<[BaseDiscovery.Instance], Error>) -> Result<[BaseDiscovery.Instance], Error>
+    {
         switch result {
         case .success(let instances):
-            do {
-                return try .success(instances.filter(self.predicate))
-            } catch {
-                return .failure(error)
-            }
-        case .failure(let error):
-            return .failure(error)
+            do { return try .success(instances.filter(self.predicate)) } catch { return .failure(error) }
+        case .failure(let error): return .failure(error)
         }
     }
 }

Sources/ServiceDiscovery/HostPort.swift

@@ -22,7 +22,5 @@ public struct HostPort: Hashable, CustomStringConvertible {
         self.port = port
     }
 
-    public var description: String {
-        "\(self.host):\(self.port)"
-    }
+    public var description: String { "\(self.host):\(self.port)" }
 }