If you create a TypeScript project in Visual Studio code in a path that contains spaces, you might end up getting the following error after configuring your build task and building the application:
> Executing task: tsc -p "c:\Projects\Test Harness Applications\TypeScript\MyTypeScriptApp\tsconfig.json" <Notice the path I used to create the application contained spaces:
error TS5042: Option 'project' cannot be mixed with source files on a command line.
The terminal process terminated with exit code: 1
"c:\Projects\Test Harness Applications\TypeScript\MyTypeScriptApp"
After a little digging I found this GitHub open issue: https://github.com/Microsoft/vscode/issues/32400. The good news is according to the information within that link, this is in process to be fixed in an upcoming version of Visual Studio Code (currently 2/2018). In the interim the solution is just to make sure the full path to your application does not contain any spaces. I verified that by doing this, the compiler issue will go away, and the project build successfully.