Angular 2/Web Api - json parsing error syntax error unexpected end of input

Question

I have a Web API controller that looks like this:

    [HttpPost]
    public IHttpActionResult Test()
    {
        return Ok();
    }

This is correct syntax, However when I try to call this from a service in Angular 2, I get the error message: "json parsing error syntax error unexpected end of input." To resolve this issue, I have to put a value into the ActionResult such as

return Ok(1)

Am I missing some configuration? My Angular 2 service call looks like this:

return this.http.post(API/Controller/Test).map(res => res.json());

Answer 1

Another way:

All my http.get, post or put call (for uniformity):

.map(this.extractData)

In extractData (UPDATED: thanks to raykrow feedback, short code):

private extractData(res: Response) {        
    return res.text() ? res.json() : {}; ;
}

Answer 2

I guess that when you receive an empty response (without payload) you don't need to call the json method. Under the hood, the XHR response is undefined, JSON.parse(undefined) is called and an error is thrown.

You could skip the call of the map operator:

return this.http.post(API/Controller/Test)/*.map(res => res.json())*/;

Answer 3

Strictly speaking if your API is returning an OK code with no content you should return 204 (no content) - Angular would also be happy with this and not try to parse anything. So your controller method would become:

[HttpPost]
public IHttpActionResult Test()
{
    return NoContent();
}