invert SwiftLint’s default trailing comma rule for compability with S…

…wiftFormat

Upon realising this clash, I hoped we could get away with just using
SwiftLint, which does have some style rules. But it doesn’t enforce some
basic things like indentation. I hope that there aren’t further clashes
between the two tools, but we won’t find out until we write more code.

.swiftlint.yml

@@ -95,3 +95,7 @@ identifier_name:
 type_name: *no_length_checks
 
 generic_type_name: *no_length_checks
+
+# For compatibility with SwiftFormat
+trailing_comma:
+  mandatory_comma: true

Package.swift

@@ -8,26 +8,29 @@ let package = Package(
     platforms: [
         .macOS(.v10_13),
         .iOS(.v12),
-        .tvOS(.v12)
+        .tvOS(.v12),
     ],
     products: [
         // Products define the executables and libraries a package produces, making them visible to other packages.
         .library(
             name: "AblyChat",
-            targets: ["AblyChat"])
+            targets: ["AblyChat"]
+        ),
     ],
     dependencies: [
         .package(url: "https://github.com/ably/ably-cocoa", from: "1.2.0"),
         .package(url: "https://github.com/SimplyDanny/SwiftLintPlugins", from: "0.55.1"),
-        .package(url: "https://github.com/nicklockwood/SwiftFormat", from: "0.54.0")
+        .package(url: "https://github.com/nicklockwood/SwiftFormat", from: "0.54.0"),
     ],
     targets: [
         // Targets are the basic building blocks of a package, defining a module or a test suite.
         // Targets can depend on other targets in this package and products from dependencies.
         .target(
-            name: "AblyChat", dependencies: [.product(name: "Ably", package: "ably-cocoa")], swiftSettings: [.enableExperimentalFeature("StrictConcurrency")]),
+            name: "AblyChat", dependencies: [.product(name: "Ably", package: "ably-cocoa")], swiftSettings: [.enableExperimentalFeature("StrictConcurrency")]
+        ),
         .testTarget(
             name: "AblyChatTests",
-            dependencies: ["AblyChat"])
+            dependencies: ["AblyChat"]
+        ),
     ]
 )

Sources/AblyChat/AblyChat.swift

@@ -1,4 +1 @@
-// The Swift Programming Language
-// https://docs.swift.org/swift-book
-
 import Ably

Tests/AblyChatTests/AblyChatTests.swift

@@ -2,6 +2,7 @@
 import XCTest
 
 final class AblyChatTests: XCTestCase {
+    // swiftlint:disable:next empty_xctest_method
     func testExample() throws {
         // XCTest Documentation
         // https://developer.apple.com/documentation/xctest