resolve test flake on evaluateJavascript

platforms/swift/Sources/ShopifyCheckoutKit/CheckoutBridge.swift

@@ -32,14 +32,24 @@ enum CheckoutBridge: CheckoutBridgeProtocol {
     }
 
     static func sendMessage(_ webView: WKWebView, messageName: String, messageBody: String?) {
+        sendMessage(
+            evaluateJavaScript: { script in
+                webView.evaluateJavaScript(script)
+            },
+            messageName: messageName,
+            messageBody: messageBody
+        )
+    }
+
+    static func sendMessage(evaluateJavaScript: (String) -> Void, messageName: String, messageBody: String?) {
         let dispatchMessageBody: String
         if let body = messageBody {
             dispatchMessageBody = "'\(messageName)', \(body)"
         } else {
             dispatchMessageBody = "'\(messageName)'"
         }
         let script = dispatchMessageTemplate(body: dispatchMessageBody)
-        webView.evaluateJavaScript(script)
+        evaluateJavaScript(script)
     }
 
     static func sendResponse(_ webView: WKWebView, messageBody: String) {

platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutBridgeTests.swift

@@ -55,29 +55,27 @@ class CheckoutBridgeTests: XCTestCase {
     }
 
     func testSendMessageShouldCallEvaluateJavaScriptPresented() {
-        let webView = MockWebView()
-        webView.expectedScript = expectedPresentedScript()
-        let evaluateJavaScriptExpectation = expectation(
-            description: "evaluateJavaScript was called"
-        )
-        webView.evaluateJavaScriptExpectation = evaluateJavaScriptExpectation
+        var evaluatedScript: String?
 
-        CheckoutBridge.sendMessage(webView, messageName: "presented", messageBody: nil)
+        CheckoutBridge.sendMessage(
+            evaluateJavaScript: { evaluatedScript = $0 },
+            messageName: "presented",
+            messageBody: nil
+        )
 
-        wait(for: [evaluateJavaScriptExpectation], timeout: 2)
+        XCTAssertEqual(evaluatedScript, expectedPresentedScript())
     }
 
     func testSendMessageWithPayloadEvaulatesJavaScript() {
-        let webView = MockWebView()
-        webView.expectedScript = expectedPayloadScript()
-        let evaluateJavaScriptExpectation = expectation(
-            description: "evaluateJavaScript was called"
-        )
-        webView.evaluateJavaScriptExpectation = evaluateJavaScriptExpectation
+        var evaluatedScript: String?
 
-        CheckoutBridge.sendMessage(webView, messageName: "payload", messageBody: "{\"one\": true}")
+        CheckoutBridge.sendMessage(
+            evaluateJavaScript: { evaluatedScript = $0 },
+            messageName: "payload",
+            messageBody: "{\"one\": true}"
+        )
 
-        wait(for: [evaluateJavaScriptExpectation], timeout: 2)
+        XCTAssertEqual(evaluatedScript, expectedPayloadScript())
     }
 
     private func expectedPresentedScript() -> String {