title: Why VS Code fails to debug sources with TS 3.7.1-rc syntax support?
body: <p>I have a code base and I am willing to use <code>typescript 3.7</code>, to be precise I use <code>3.7.1-rc</code>. I could build the source with the command line and even run tests in the command line, but when I want to debug the project using <code>F5</code>, it fails, vs code claims there are some errors, but it shows nothing in the <code>Problems</code> tab, but in the <code>Outputs</code> it says: </p>
  
  <pre><code>sample.ts(42,53): error TS1109: Expression expected.
  sample.ts(42,68): error TS1005: ':' expected.
  </code></pre>
  
  <p>the source file is something like the following: </p>
  
  <pre><code>if (filterElements || configuration.classes?.filterElements) {
              const filter = filterElements || configuration.classes!.filterElements;
  
  </code></pre>
  
  <p>in which column 53 is where the question mark exists, and 68 is where the close parenthesis exists. I even tried the VS Code Insider, it behaves the same.</p>
  
  <p>I have no idea what to do. I have the same error where ever I used <code>?</code> of <code>3.7</code>.</p>