Add new --silence-deprecation-warnings flag

CHANGELOG.md

@@ -25,6 +25,11 @@
   (e.g. `@testable`, `@_exported`, ...).  
   [hiltonc](https://github.com/hiltonc)
 
+* Add new `--quiet-deprecation-warnings` flag that silences deprecation
+  warnings that would otherwise be printed to the console.  
+  [SimplyDanny](https://github.com/SimplyDanny)
+  [#4989](https://github.com/realm/SwiftLint/issues/4989)
+
 * Do not trigger `redundant_self_in_closure` rule when another idenfier `x` in
   scope shadows the field accessed by `self.x` to avoid semantical changes.  
   [SimplyDanny](https://github.com/SimplyDanny)

Source/SwiftLintCore/Models/Issue.swift

@@ -47,6 +47,9 @@ public enum Issue: LocalizedError, Equatable {
     /// An error that occurred when parsing YAML.
     case yamlParsing(String)
 
+    /// Flag to enable warnings for deprecations being printed to the console. Printing is enabled by default.
+    public static var printDeprecationWarnings = true
+
     /// Wraps any `Error` into a `SwiftLintError.genericWarning` if it is not already a `SwiftLintError`.
     ///
     /// - parameter error: Any `Error`.
@@ -75,6 +78,9 @@ public enum Issue: LocalizedError, Equatable {
 
     /// Print the issue to the console.
     public func print() {
+        if case .ruleDeprecated = self, !Self.printDeprecationWarnings {
+            return
+        }
         queuedPrintError(errorDescription)
     }
 

Source/swiftlint/Commands/Lint.swift

@@ -13,6 +13,8 @@ extension SwiftLint {
         var useSTDIN = false
         @Flag(help: quietOptionDescription(for: .lint))
         var quiet = false
+        @Flag(help: "Don't print deprecation warnings.")
+        var silenceDeprecationWarnings = false
         @Option(help: "The directory of the cache used when linting.")
         var cachePath: String?
         @Flag(help: "Ignore cache when linting.")
@@ -23,6 +25,8 @@ extension SwiftLint {
         var paths = [String]()
 
         func run() async throws {
+            Issue.printDeprecationWarnings = !silenceDeprecationWarnings
+
             let allPaths: [String]
             if let path {
                 // TODO: [06/14/2024] Remove deprecation warning after ~2 years.