Scrapboxで見出しのレベルを変えるショートカット

script.js

const pattern = /\[(\*+) +([^ ].*)\]/

function deleteLine() {
  var eventToMoveToStartOfLine = new KeyboardEvent('keydown', {
    ctrlKey: true,
    keyCode: '69', // e
    bubbles: true,
    cancelable: true,
  })
  document.getElementById('text-input').dispatchEvent(eventToMoveToStartOfLine)
  var eventToMoveToEndOfLine = new KeyboardEvent('keydown', {
    ctrlKey: true,
    shiftKey: true,
    keyCode: '65', // a
    bubbles: true,
    cancelable: true,
  })
  document.getElementById('text-input').dispatchEvent(eventToMoveToEndOfLine)
  var eventToDelete = new KeyboardEvent('keydown', {
    keyCode: '8', // Backspace
    bubbles: true,
    cancelable: true,
  })
  document.getElementById('text-input').dispatchEvent(eventToDelete)
}

document.addEventListener('keydown', e => {
  if (e.ctrlKey && e.key == '8') {
    const currentContent = document.querySelector('.lines div.line.cursor-line').textContent
    var content

    if (e.shiftKey) {
      if (!pattern.test(currentContent)) { return }

      const [, asterisks, title] = currentContent.match(pattern)
      const slicedAsterisks = asterisks.slice(1, asterisks.length)
      if (asterisks.length == 1) {
        content = title
      } else {
        content = `[${asterisks.slice(1, asterisks.length)} ${title}]`
      }
    } else {
      if (pattern.test(currentContent)) {
        const [, asterisks, title] = currentContent.match(pattern)
        content = `${asterisks}* ${title}`
      } else {
        content = `* ${currentContent}`
      }
      content = `[${content}]`
    }

    deleteLine()
    const textInput = document.getElementById('text-input')
    textInput.value = content
    textInput.focus()
    const inputEvent = new InputEvent('input', { bubbles: true, cancelable: true })
    textInput.dispatchEvent(inputEvent)
  }
})