tasks.json

// Available variables which can be used inside of strings.
// ${workspaceRoot}: the root folder of the team
// ${file}: the current opened file
// ${fileBasename}: the current opened file's basename
// ${fileDirname}: the current opened file's dirname
// ${fileExtname}: the current opened file's extension
// ${cwd}: the current working directory of the spawned process
// A task runner that calls a custom npm script that compiles the extension.
{
  "version": "2.0.0",
  // we want to run npm
  "command": "npm",
  // we run the custom script "compile" as defined in package.json
  "args": [
    "run",
    "watch",
    "--loglevel",
    "silent"
  ],
  // The tsc compiler is started in watching mode
  "isBackground": true,
  // use the standard tsc in watch mode problem matcher to find compile problems in the output.
  "problemMatcher": "$tsc-watch",
  "tasks": [
    {
      "label": "npm",
      "type": "shell",
      "command": "npm",
      "args": [
        "run",
        "watch",
        "--loglevel",
        "silent"
      ],
      "isBackground": true,
      "problemMatcher": "$tsc-watch",
      "group": "build"
    }
  ]
}