title: How to pass parameter to unnamed route: TypeError: Right-hand side of 'instanceof' is not callable
body: <p>I have a route:</p>
  <p><strong>router.js</strong>:</p>
  <pre><code>       {
              path: &quot;/books/new/:title&quot;,
              name: &quot;new_book&quot;,
              component: () =&gt; 
  import('./components/user/NewBookView.vue')
          }
  </code></pre>
  <p>to which I try to push via router:</p>
  <p><strong>CreateBook.vue</strong>:</p>
  <pre><code>this.$router.push({
      name: &quot;new_book&quot;,
      params: {
           title: this.bookJson.data.title,
           book: this.bookJson.data
      }
  });
  </code></pre>
  <p>However I get a</p>
  <pre><code>Error in nextTick: &quot;TypeError: 
  Right-hand side of 'instanceof' is not callable&quot;
  </code></pre>
  <p>error.</p>
  <p>I need the <code>bookJson</code> to be passed as param to my <code>NewBookView.vue</code> component:</p>
  <p><strong>NewBookView.vue</strong>:</p>
  <pre><code>...
          data:  function()  {
              return {
                  book: JSON
              }
          },
          created() {
              this.book = 
  this.$route.params.book;
          }
  ...
  </code></pre>
  <p>I tried to do</p>
  <pre><code>this.$router.push({
      path: &quot;/books/new/&quot; + 
  this.booksJson.data.title,
      params: {
           book: this.bookJson.data
      }
  });
  </code></pre>
  <p>but the <code>book</code> parameter seems to be <code>undefined</code>.</p>
  <p>So it seems that I can't pass the parameter unless the route is named, but if it's named I can't push to it either.</p>
  <p><strong>EDIT</strong>: I tried to change it to this, but still get the <code>Error in nextTick: &quot;TypeError: Right-hand side of 'instanceof' is not callable&quot;</code> error:</p>
  <p><strong>router.js</strong>:</p>
  <pre><code>{
      path: &quot;/books/new/:title&quot;,
      name: &quot;new_book&quot;,
      component: () =&gt; import('./components/user/NewBookView.vue'),
      props: route =&gt; ({
          // set component property book to the route.params.book value
          book: route.params.book,
          ...route.params
      })
  }
  </code></pre>
  <p><strong>CreateBook.vue</strong>:</p>
  <pre><code>this.$router.push({
      name: &quot;new_book&quot;,
      params: {
           title: this.bookJson.data.title,
           book: this.bookJson.data
      }
  });
  })
  </code></pre>
  <p><strong>NewBookView.vue</strong>:</p>
  <pre><code>export default {
      props:  {
          book: JSON
      },
      created() {
          this.props.book = this.$route.params.book;
      }
  }
  </code></pre>