title: Why hasn't this value changed ,use slodity 0.8.6
body: <p>I use hardhat test my contract,contract code like this:</p>
  <pre><code>uint256 public investLength;
      
  function A()external{
      uint256 id = investLength++;
      _a(id);
  }
  
  function _a(uint256 _Id) internal returns (address) {
     require(_id != 0, 'id zero');
  }
  </code></pre>
  <p>when running test,return <strong>id zero</strong>.This code doesn't seem to be working =&gt;<strong>investLength++</strong>,this value did not change to 1;</p>