BUG: Setting the text content programmatically clears it in the canvas

Try using the .getEl method on the component then setting the element directly.

const editor = grapesjs.init({
  container: '#gjs',
  fromElement: 1,
  height: '100%',
  storageManager: { type: 0 },
  plugins: ['gjs-blocks-basic']
});

setTimeout(() => {
  const component = editor.getWrapper().find('.test-text')[0]
  const el = component.getEl();
  el.textContent = "test"
}, 1000)

  const component = editor.getWrapper().find('.test-text')[0]
  const el = component.getEl();
  el.textContent = "test"

Problem with this is that when you export the HTML, it returns the old text.

setTimeout(() => {
  const component = editor.getWrapper().find('.test-text')[0]
  const el = component.getEl();
  el.textContent = "test"

  console.log(component.toHTML())
  // <div class="test-text" id="i387">Hello World!!!</div>
}, 1000)

@mannyyang where did you find the usage of set('content', ...? It's more like private property and you should never use it.

To update inner components programmatically use component.components('test')