How to solve Mexican wave algorithm in JavaScript

The Mexican Wave
The wave (known as the Mexican wave in the English-speaking world outside North America) is an example of metachronal rhythm achieved in a packed stadium when successive groups of spectators briefly stand, yell, and raise their arms. Immediately upon stretching to full height, the spectator returns to the usual seated position.

The result is a wave of standing spectators that travels through the crowd, even though individual spectators never move away from their seats. In many large arenas the crowd is seated in a contiguous circuit all the way around the sport field, and so the wave is able to travel continuously around the arena; in discontinuous seating arrangements, the wave can instead reflect back and forth through the crowd. When the gap in seating is narrow, the wave can sometimes pass through it. Usually only one wave crest will be present at any given time in an arena, although simultaneous, counter-rotating waves have been produced. (Source Wikipedia)

Task
Your task is to create a function that turns a string into a Mexican Wave. You will be passed a string and you must return that string in an array where an uppercase letter is a person standing up.

Solution
Before diving into coding make sure to understand the problem and visualize the solution in form of pseudo code, break it down into steps.

Steps

1. Create an array to store the results
2. return empty array if the string is empty
3. Loop through the letters in the string
4. Make a copy of the string to an array
5. if there is a space in the string skip that space,
6. Covert each letter of the copied string array to uppercase then join them together as one string
7. then push them to our result array and finally return the result array.

const wave=(str)=>{
   let result = [];
   if([...str].length === 0) return [];
   for(let i = 0; i < str.length; i++){
       let copy = str.split('');
       if(copy[i] === ' ') continue;
       copy[i] = copy[i].toUpperCase('');
       result.push(copy.join(''))
   }
   return result
}
console.log(wave('two words'))
/* ["Two words", "tWo words", "twO words", "two Words", "two wOrds", "two woRds", "two worDs", "two wordS"]; */