title: problemMatcher for Typescript in Webpack watch mode
body: <p>I'm using <code>fork-ts-checker-webpack-plugin</code>, and I want to write a problem matcher that will display the set of problems returned by the compiler in real time as Webpack recompiles in the background. I've tried this problem matcher in my build task:</p>
  
  <pre><code>{
      "type": "shell",
      "command": "webpack -w --config webpack.dev.js",
      "label": "Webpack (Dev, Continuous)",
      "group": "build",
      "promptOnClose": true,
      "isBackground": true,
      "problemMatcher": {
          "owner": "webpack",
          "severity": "error",
          "fileLocation": "absolute",
          "source": "webpack typescript",
          "background": {
              "activeOnStart": true
          },
          "pattern": [
              {
                  "regexp": "ERROR in (.*?)\\((\\d+),(\\d+)\\)",
                  "file": 1,
                  "line": 2,
                  "column": 3
              },
              {
                  "regexp": "[A-Za-z0-9-]+:(.*)",
                  "message": 2,
                  "code": 1
              }
          ]
      }
  }
  </code></pre>
  
  <p>But this doesn't work. </p>
  
  <p>My problem matcher is supposed to match lines like these:</p>
  
  <blockquote>
  <pre><code>ERROR in I:/component/page/admin/reports/checkouts.vue(44,9):
  no-floating-promises: Promises must be handled appropriately
  ERROR in I:/component/page/admin/reports/fines.vue(66,9):
  no-floating-promises: Promises must be handled appropriately
  ERROR in I:/component/page/admin/users/user.vue(220,9):
  no-floating-promises: Promises must be handled appropriately
  ERROR in I:/component/page/admin/users/user.vue(232,9):
  no-floating-promises: Promises must be handled appropriately
  ERROR in I:/component/page/admin/users/user.vue(240,9):
  no-floating-promises: Promises must be handled appropriately
  ERROR in I:/component/page/admin/users/users.vue(40,9):
  no-floating-promises: Promises must be handled appropriately
  </code></pre>
  </blockquote>
  
  <p>Why isn't this working?</p>