Custom fontFamily for Text not working in either iOS or Android

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

Environment: OS: macOS High Sierra 10.13.2 Node: 9.4.0 Yarn: 1.3.2 npm: 5.6.0 Watchman: 4.9.0 Xcode: Xcode 9.2 Build version 9C40b Android Studio: 3.0 AI-171.4443003

Packages: (wanted => installed) react: 16.2.0 => 16.2.0 react-native: 0.52.0 => 0.52.0

Steps to Reproduce

1. Place contents of Nunito font fro Google (*ttf files) into project root’s assets/fonts/ directory (here are the contents of that directory)
2. Add the following to my package.json:

"rnpm": {
    "assets": [
	"./assets/fonts/"
    ]
},

1. Run react-native link
2. Verify that both Xcode/Info.plist and Android Studio reflects the new Nunito font:
3. Run ./gradlew clean from android directory, fresh install of node_modules from scratch, fresh install of pods from android directory, restart both Xcode and Android Studio, reset npm cache, uninstall and reinstall app on variety of emulators and devices
4. Try setting Text.defaultProps.style = {fontFamily: 'Nunito'}; in root component (App.js)
5. Try setting {fontFamily: 'Nunito'} style for a single Text component

Expected Behavior

I expected globally setting Text.defaultProps.style = {fontFamily: 'Nunito'}; to result in the font being applied everywhere in my app, or at the very least setting {fontFamily: 'Nunito'} style for a single Text component to work.

Actual Behavior

In all cases, I still only observe my app using the default RN font family.

[lwinkyawmyat]

Can you try to match font filename and fontFamily name.

{ 
  fontFamily: 'Nunito-Reqular' // if filename is Nunito-Reqular.ttf
}

{ 
  fontFamily: 'Nunito-Bold' // if filename is Nunito-Bold.ttf
}

[hamadasamir85]

I found out that font names on ios are different from the file name. the files name might be ‘GE_SS_TWO_MEDIUM.ttf’ but if you check the font info with fontbook app you will find the name is ‘GE SS TWO’. using the file name as fontfamily works on android but does not work on ios ,and vise versa so my solution was to use Platform check on style

fontFamily: Platform.OS === 'ios' ? 'GE SS TWO':'GE_SS_TWO_MEDIUM'

worked for me so far