Added layoutMode to BlueprintViewRenderMetrics to expose which la…

…yout mode was used to render a Blueprint view. (square#452)

BlueprintUI/Sources/BlueprintView/BlueprintView.swift

@@ -424,6 +424,7 @@ public final class BlueprintView: UIView {
         metricsDelegate?.blueprintView(
             self,
             completedRenderWith: .init(
+                layoutMode: layoutMode,
                 totalDuration: viewUpdateEndTime - startTime,
                 layoutDuration: layoutEndTime - startTime,
                 viewUpdateDuration: viewUpdateEndTime - layoutEndTime
@@ -530,10 +531,15 @@ public protocol BlueprintViewMetricsDelegate: AnyObject {
 
 public struct BlueprintViewRenderMetrics {
 
+    /// The layout mode used to render the view.
+    public var layoutMode: LayoutMode
+
     /// The total time it took to apply a new element.
     public var totalDuration: TimeInterval
+
     /// The time it took to lay out and measure the new element.
     public var layoutDuration: TimeInterval
+
     /// The time it took to update the on-screen views for the element.
     public var viewUpdateDuration: TimeInterval
 }

BlueprintUI/Sources/Layout/LayoutMode.swift

@@ -31,6 +31,16 @@ public enum LayoutMode: Equatable {
     /// A newer layout system with some optimizations made possible by ensuring elements adhere
     /// to a certain contract for behavior.
     public static let caffeinated = Self.caffeinated()
+
+    /// The name of the layout mode.
+    public var name: String {
+        switch self {
+        case .legacy:
+            return "Legacy"
+        case .caffeinated:
+            return "Caffeinated"
+        }
+    }
 }
 
 extension LayoutMode: CustomStringConvertible {

BlueprintUI/Tests/LayoutModeTests.swift

@@ -0,0 +1,12 @@
+import XCTest
+@testable import BlueprintUI
+
+class LayoutModeTests: XCTestCase {
+
+    func testName() {
+        // These names may end up being propagated as analytics properties,
+        // so be aware that renaming them can impact existing queries/reports.
+        XCTAssertEqual(LayoutMode.caffeinated.name, "Caffeinated")
+        XCTAssertEqual(LayoutMode.legacy.name, "Legacy")
+    }
+}

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `layoutMode` to `BlueprintViewRenderMetrics` to expose which layout mode was used to render a Blueprint view.
+
 ### Removed
 
 ### Changed