Core htmx AJAX headers

• request history from server with error status code throws error event3ms ‣

  this.server.respondWith('GET', '/test', function(xhr) {
    xhr.requestHeaders['HX-Request'].should.be.equal('true')
    xhr.respond(404, {}, '')
  })
  var invokedEvent = false
  var handler = htmx.on('htmx:historyCacheMissLoadError', function(evt) {
    invokedEvent = true
  })
  htmx._('loadHistoryFromServer')('/test')
  this.server.respond()
  invokedEvent.should.equal(true)
  htmx.off('htmx:historyCacheMissLoadError', handler)