Add OSSignposter sugar and make Logger not fail when testing.

Sources/DependenciesAdditionsBasics/Internal/RuntimeWarnings.swift

@@ -22,7 +22,7 @@
 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
-
+import Foundation
 @_transparent
 @usableFromInline
 @inline(__always)

Sources/LoggerDependency/Logger.swift

@@ -21,11 +21,19 @@
   @available(macOS 11.0, iOS 14.0, watchOS 7.0, tvOS 14.0, *)
   extension Logger: DependencyKey {
     public static var liveValue: Logger { Logger() }
-    public static var testValue: Logger {
+    /// - Note: It doesn't make a lot of sense to fail by default because we can't pass an
+    /// inspectable `Logger` value to assert logged messages when testing. Given the prominence of
+    /// logging failing by default is more annoying than useful in real-life scenarios.
+    /// Users who wish to assert that no logging occurs can override the `\.logger` dependency with
+    /// the `.unimplemented` logger.
+    public static var testValue: Logger { Logger() }
+    public static var previewValue: Logger { Logger() }
+
+    /// A `Logger` that fails when accessed while testing.
+    public static var unimplemented: Logger {
       XCTFail(#"Unimplemented: @Dependency(\.logger)"#)
       return Logger()
     }
-    public static var previewValue: Logger { Logger() }
   }
 
   @available(macOS 11.0, iOS 14.0, watchOS 7.0, tvOS 14.0, *)
@@ -54,4 +62,12 @@
       Logger(subsystem: Bundle.main.bundleIdentifier ?? "", category: category)
     }
   }
+
+  @available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)
+  extension Logger {
+    /// Creates a `OSSignposter` to emit signpost to this logger value.
+    public var signpost: OSSignposter {
+      OSSignposter(logger: self)
+    }
+  }
 #endif

Tests/LoggerDependencyTests/LoggerDependencyTests.swift

@@ -9,13 +9,9 @@
   final class LoggerDependencyTests: XCTestCase {
     @Dependency(\.logger) var logger
 
-    #if (os(iOS) || os(macOS) || os(tvOS) || os(watchOS)) && DEBUG
-      func testFailingTestLogger() {
-        XCTExpectFailure {
-          logger.log("TestValue")
-        }
-      }
-    #endif
+    func testNotFailingTestLogger() {
+      logger.log("TestValue")
+    }
 
     func testLoggerCategory() {
       @Dependency(\.logger["Logger.Dependency.Testing"]) var logger