walk-text.js

const walk = (acc = [], outer) => {
  if (typeof outer === null) {
    return acc
  }
  if (typeof outer === 'string') {
    if (outer === ' ') {
      return acc
    }
    if (outer === '\n') {
      return [...acc,"<br></br>"];
    }
    return [...acc, outer];
  }
  if (Array.isArray(outer)) {
    let mine = [];
    for (const inner of outer) {
      if(Array.isArray(inner)) {
        mine = [...mine, ...walk([],inner)]
      }
      else {
        mine = [...mine, walk([],inner)]
      }
      
    }
    return [...acc, ...mine];
  }
  if (outer.nodeType === 3) {
    return [...acc, outer.textContent];
  }
  if (outer.nodeType === 1 && outer.hasChildNodes()) {
    let mine = [];
    for (const inner of outer.childNodes) {
      mine = [...mine, ...walk([], inner)]
    }
    return [...acc, ...mine];
  }
  return acc;
}