https://www.reddit.com/r/reactnative/comments/bbp3xd/help_me_solve_this_code/

gistfile1.txt

// solution 1
lampExists(lamp){
  if(lamp.toLowerCase().includes(this.state.query.toLowerCase()))  {
    return true
  } else {
    return AsyncStorage.getItem(lamp).then(value=> {
      if(value !== null && value
        .toLowerCase()
        .includes(this.state.query.toLowerCase())) {
        return true;
      }
      return false;
    }).catch(err=>alert(err));
  }
}

// solution 2
async lampExists(lamp){
  let myBool;
  if(lamp.toLowerCase().includes(this.state.query.toLowerCase()))  {
    return true
  } else {
    const value = await AsyncStorage.getItem(lamp);

    if(value !== null && value
      .toLowerCase()
      .includes(this.state.query.toLowerCase())) {
      return true;
    }
    return false;
  }
}


// Update
class YourComponent extends React.Component {
  constructor(props) {
    this.state = {
      lamps: [],
      loading: false,
    }
    this.fetchLamps = this.fetchLamps.bind(this);
  }

  componentDidMount() {
    this.getLamps()
  }

  asycn getLamps() {
    // set loading state to true
    this.setState({ loading: true });
    
    // Do async work here
    const lamps = await // fetch your lamps
    // probably some error handling logic here
    
    // set lamps to state and set loading state to false
    this.setState({
      lamps: lamps,
      loading: false,
    });
  }
  
  render() {
    if (this.state.loading) {
      return <Text>Loading</Tex>;
    }
    return (
      <View>
        {
          this.state.lamps.map(lamp => (
            <LampsList 
              key={lamp} 
              lamp={lamp} 
              navigation={this.props.navigation} 
            /> 
          )
        }
      </View>
    );
  }
}

Both solutions returns a promise instead of boolean.
Cannot extract boolean by using .then function in render function of React as it doesn't allow me.
Posting my render function code as well, so you can get a better idea.
{this.state.lamps.map(lamp => { if (this.state.query === "") { return <LampsList key={lamp} lamp={lamp} navigation={this.props.navigation} /> } else { return (this.lampExists(lamp)?<LampsList key={lamp} lamp={lamp} navigation={this.props.navigation} />:null) } })}

{this.state.lamps.map(lamp => { if (this.state.query === "") { return <LampsList key={lamp} lamp={lamp} navigation={this.props.navigation} /> } else { this.lampExists(lamp) .then(result=>{ if(result===true){ return <LampsList key={lamp} lamp={lamp} navigation={this.props.navigation} /> }else{ return null } }) .catch(err=>alert(err)); } })}
If I change my render function to this, it still doesn't work, because the component is again not getting returned and only a promise is getting returned which won't display my component.