max.pipe.ts

import { Pipe, PipeTransform  } from '@angular/core';
import { isArray } from '../utils/utils';

@Pipe({ 
  name: 'max' 
})
export class MaxPipe implements PipeTransform {
  
  transform (input: any): any {
    
    if (!isArray(input)) {
      return input;
    }
    
    if (input.length === 0) {
      return undefined;
    }
    
    let max = input[0];
    
    input.forEach((value: any) => {
      
      if (max < value) {
        max = value;
      }
    });
    
    return max;
  }
}