Intl.NumberFormat with compact notation doesn't display formatting

[believer]

Description

Intl.NumberFormat has a notation option that handles truncating a number and displaying formatting as text. This doesn't work with notation: 'compact' and the associated compactDisplay option.

Might be related to facebook/hermes#1317

Steps to reproduce

// Tested with other locales without any difference.
const locale = 'en-US'

const numberFormatter = new Intl.NumberFormat(locale, { notation: 'compact' })
const percentFormatter = new Intl.NumberFormat(locale, { style: 'percent', notation: 'compact' })
const numberLongFormatter = new Intl.NumberFormat(locale, { notation: 'compact', compactDisplay: 'long' })
const percentLongFormatter = new Intl.NumberFormat(locale, { style: 'percent', notation: 'compact', compactDisplay: 'long' })

numberFormatter.format(123456789) // Displays "123,456,789", but should display "123M"
percentFormatter.format(1234) // Displays "123,400 %", but should display "123K%"
numberLongFormatter.format(123456789) // Displays "123,456,789", but should display "123 million"
percentLongFormatter.format(1234) // Displays "123,400 %", but should display "123 thousand%"

React Native Version

0.73.4

Affected Platforms

Runtime - iOS

Output of npx react-native info

System:
  OS: macOS 14.3
  CPU: (10) arm64 Apple M2 Pro
  Memory: 118.86 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 18.18.2
    path: ~/Library/Caches/fnm_multishells/41192_1708331264383/bin/node
  Yarn:
    version: 1.22.19
    path: ~/code/seb/Spark-blackbird/apps/blackbird/node_modules/.bin/yarn
  npm:
    version: 9.8.1
    path: ~/Library/Caches/fnm_multishells/41192_1708331264383/bin/npm
  Watchman:
    version: 2024.01.22.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.15.2
    path: /Users/rickard/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 23.2
      - iOS 17.2
      - macOS 14.2
      - tvOS 17.2
      - visionOS 1.0
      - watchOS 10.2
  Android SDK:
    API Levels:
      - "33"
      - "34"
    Build Tools:
      - 30.0.3
      - 33.0.0
      - 33.0.1
      - 34.0.0
    System Images:
      - android-33 | Google APIs ARM 64 v8a
      - android-33 | Google Play ARM 64 v8a
      - android-34 | Google APIs ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: 2023.1 AI-231.9392.1.2311.11255304
  Xcode:
    version: 15.2/15C500b
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.10
    path: /usr/bin/javac
  Ruby:
    version: 3.2.2
    path: /Users/rickard/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 13.5.1
    wanted: "*"
  react:
    installed: 18.2.0
    wanted: "*"
  react-native:
    installed: 0.73.4
    wanted: "*"
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: false

Stacktrace or Logs

No stacktrace or logs

Reproducer

https://snack.expo.dev/dgxZ741GIb4EfFyAnyQYp

Screenshots and Videos

Web	iOS

[neildhar]

Thanks for reporting this, this has previously been discussed in #1035, so closing it as a duplicate. Our current approach to Intl on iOS makes this difficult to implement, but we intend to redesign our Intl implementation in the long term to add support for a broader set of functionality.