Compare rule IDs and configurations with reference (#5510)

This new test ensures that rule IDs and their option names do not get
changed inadvertently.

The file can easily be updated by running:

```bash
swift run swiftlint rules --config-only --default-config > Tests/IntegrationTests/default_rule_configurations.yml
```

Package.swift

@@ -131,6 +131,9 @@ let package = Package(
                 "SwiftLintFramework",
                 "SwiftLintTestHelpers"
             ],
+            exclude: [
+                "default_rule_configurations.yml"
+            ],
             swiftSettings: swiftFeatures
         ),
         .testTarget(

Tests/BUILD

@@ -141,7 +141,10 @@ swift_library(
 
 swift_test(
     name = "IntegrationTests",
-    data = ["//:LintInputs"],
+    data = [
+        "//:LintInputs",
+        "IntegrationTests/default_rule_configurations.yml"
+    ],
     visibility = ["//visibility:public"],
     deps = [":IntegrationTests.library"],
 )

Tests/IntegrationTests/IntegrationTests.swift

@@ -53,6 +53,23 @@ class IntegrationTests: SwiftLintTestCase {
         }
     }
 
+    func testDefaultConfigurations() {
+        let defaultConfig = Configuration(rulesMode: .allEnabled).rules
+            .map { type(of: $0) }
+            .filter { $0.identifier != "custom_rules" }
+            .map {
+                """
+                \($0.identifier):
+                \($0.init().configurationDescription.yaml().indent(by: 2))
+                """
+            }
+            .joined(separator: "\n")
+        let referenceFile = URL(fileURLWithPath: #file)
+            .deletingLastPathComponent()
+            .appendingPathComponent("default_rule_configurations.yml")
+        XCTAssertEqual(defaultConfig + "\n", try String(contentsOf: referenceFile))
+    }
+
     func testSimulateHomebrewTest() {
         // Since this test uses the `swiftlint` binary built while building `SwiftLintPackageTests`,
         // we run it only on macOS using SwiftPM.