fix(ios): Resolve getNewScreenTimeToDisplay Promise with number not array

`getTimeToDisplay:` typed its block as `RCTResponseSenderBlock` (the
callback convention that wraps results in an `NSArray`), but it is only
invoked via the Promise-based `getNewScreenTimeToDisplay` bridge method,
whose `RCTPromiseResolveBlock` expects a raw value. The Promise therefore
resolved with a single-element array instead of a timestamp number. The
array survived the duration arithmetic via coercion but was assigned
directly as the TTID span's `timestamp`, producing a spurious
`deadline_exceeded` status and an inflated duration.

Retype the block to `RCTPromiseResolveBlock` and resolve with the raw
timestamp (and `nil` on non-iOS instead of an empty array). Adds a native
regression test asserting the resolve value is a scalar `NSNumber`.

Fixes #6433

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: antonis

CHANGELOG.md

@@ -12,6 +12,10 @@
 
 - Add `Sentry.reportFullyDisplayed()` imperative API for signaling Time to Full Display ([#6419](https://github.com/getsentry/sentry-react-native/pull/6419))
 
+### Fixes
+
+- Fix iOS time-to-initial-display fallback spans reporting a spurious `deadline_exceeded` status and inflated duration ([#6433](https://github.com/getsentry/sentry-react-native/issues/6433))
+
 ## 8.18.0
 
 ### Features

packages/core/RNSentryCocoaTester/RNSentryCocoaTesterTests/RNSentryTimeToDisplayTests.swift

@@ -30,6 +30,29 @@ final class RNSentryTimeToDisplayTests: XCTestCase {
         XCTAssertNotNil(newestEntry)
     }
 
+    func testGetTimeToDisplayResolvesWithNumberNotArray() {
+        let sut = RNSentryTimeToDisplay()
+        let expectation = self.expectation(description: "resolve block is called")
+        var resolvedValue: Any?
+
+        // `getTimeToDisplay:` is invoked with an `RCTPromiseResolveBlock` from the
+        // Promise-based `getNewScreenTimeToDisplay` bridge method, so it must resolve
+        // with a raw timestamp value and never wrap it in an array.
+        sut.getTimeToDisplay { value in
+            resolvedValue = value
+            expectation.fulfill()
+        }
+
+        waitForExpectations(timeout: 5)
+
+        XCTAssertFalse(resolvedValue is [Any],
+                       "getTimeToDisplay must resolve with a scalar timestamp, not an array")
+        let number = try? XCTUnwrap(resolvedValue as? NSNumber,
+                                    "getTimeToDisplay must resolve with an NSNumber timestamp")
+        XCTAssertNotNil(number)
+        XCTAssertGreaterThan(number?.doubleValue ?? 0, 0)
+    }
+
     func testHandlesEarlyPoppedValues() {
         let maxSize = TIME_TO_DISPLAY_ENTRIES_MAX_SIZE + 1
         for i in 1...maxSize {

packages/core/ios/RNSentryTimeToDisplay.h

@@ -9,6 +9,6 @@ static const int TIME_TO_DISPLAY_ENTRIES_MAX_SIZE = 50;
 + (void)setActiveSpanId:(NSString *)spanId;
 + (void)putTimeToInitialDisplayForActiveSpan:(NSNumber *)timestampSeconds;
 
-- (void)getTimeToDisplay:(RCTResponseSenderBlock)callback;
+- (void)getTimeToDisplay:(RCTPromiseResolveBlock)callback;
 
 @end

packages/core/ios/RNSentryTimeToDisplay.m

@@ -6,7 +6,7 @@
 // React Native bridge / JS thread (setActiveSpanId, pop). Synchronize every access.
 @implementation RNSentryTimeToDisplay {
     CADisplayLink *displayLink;
-    RCTResponseSenderBlock resolveBlock;
+    RCTPromiseResolveBlock resolveBlock;
 }
 
 static NSMutableDictionary<NSString *, NSNumber *> *screenIdToRenderDuration;
@@ -92,7 +92,7 @@ + (void)putTimeToDisplayFor:(NSString *)screenId value:(NSNumber *)value
 }
 
 // Rename requestAnimationFrame to getTimeToDisplay
-- (void)getTimeToDisplay:(RCTResponseSenderBlock)callback
+- (void)getTimeToDisplay:(RCTPromiseResolveBlock)callback
 {
     // Store the resolve block to use in the callback.
     resolveBlock = callback;
@@ -102,7 +102,7 @@ - (void)getTimeToDisplay:(RCTResponseSenderBlock)callback
     displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(handleDisplayLink:)];
     [displayLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
 #else
-    resolveBlock(@[]); // Return nothing if not iOS.
+    resolveBlock(nil); // Return nothing if not iOS.
 #endif
 }
 
@@ -114,7 +114,7 @@ - (void)handleDisplayLink:(CADisplayLink *)link
 
     // Ensure the callback is valid and pass the current time back
     if (resolveBlock) {
-        resolveBlock(@[ @(currentTime) ]); // Call the callback with the current time
+        resolveBlock(@(currentTime)); // Resolve the promise with the current time
         resolveBlock = nil; // Clear the block after it's called
     }