title: Incrementing values with Vuex Module Decorators and TS
body: <p>I'm having a big issue when it comes to incrementing data.</p>
  <pre class="lang-js prettyprint-override"><code>@Module
  class Mod extends VuexModule {
     public value = 2; // this is only accessible within a MutationAction when using this.state.value, but has a lot of type errors.
  
     @MutationAction({ mutate: [&quot;value&quot;] })
     async valueIncrement(): Promise&lt;Record&lt;&quot;value&quot;, number&gt;&gt; {
        const req: AxiosRequest = await axios.get(&quot;...randomValue/&quot;);
  
        return {
           value: this.value += req.data // this doesn't work because this.value is undefined
        }
     }
  }
  </code></pre>
  <p>It seems <code>MutationAction</code> doesn't have access to the module state?</p>
  <p>Another solution that I found, which looks like a workaround, is to set <code>(this.state as this).value</code>.</p>
  <p>Is there some way to access the state directly from a <code>MutationAction</code>, some extra configuration maybe?</p>