title: How can I fix quasar typescript file type error
body: <p>I'm trying to learn quasar with typescript.
  I got a type error when I code file upload.</p>
  <p>Below is my code. Type error occurs in the parameter of the form.append() method.
  error message is</p>
  <p><em>&quot;Argument of type 'Ref&lt;File | null&gt;' is not assignable to parameter of type 'string | Blob'.&quot;</em></p>
  <p>I have no idea how can I set the type of file variable.</p>
  <pre><code>&lt;script setup lang=&quot;ts&quot;&gt;
  import { ref, Ref } from 'vue';
  import { QFile } from 'quasar';
  
  const file: Ref&lt;File | null&gt; = ref(null);
  
  const pickFile = (): void =&gt; {
    console.log(file.value);
    const formData = new FormData();
    formData.append('file', file);
    console.log(file.value);
  };
  &lt;/script&gt;
  
  &lt;template&gt;
    &lt;q-file v-model=&quot;file&quot; label=&quot;File Upload&quot; @update:model-value=&quot;pickFile()&quot;&gt;
      &lt;template #prepend&gt;
        &lt;q-icon name=&quot;mdi-attachment&quot;&gt;&lt;/q-icon&gt;
      &lt;/template&gt;
    &lt;/q-file&gt;
  &lt;/template&gt;
  </code></pre>
  <p><a href="https://i.stack.imgur.com/KhYjO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KhYjO.png" alt="enter image description here" /></a></p>