TrafficControl: Testing, Bug in Station Coordinate Check

When developing the unit tests, I'll only cover the interesting ones (the ones that exposes bugs in my code) in the blog.

One such test case is stationTest.invalidFloatCoordinatesAtCreation. 

The test case creates a station at 105°N, 13°E, and also another station at 55°N, 213°E. When testing, the result is:

The first coordinate is too big, but is parsed to the station anyways. In the second case, the coordinates are wrongly accepted.

The code is checking only the latitude for correct values. It also doesn't set the coordinate to 0, if the values are bad.

The new code that is passing is:

I also added a check in station::getLatitude and getLongitude, so that it returns 0 if hasCoordinates is false.

I'll investigate if I can define a more generic algorithm for validating coordinates, since that will be usefulwhen validating tracks in the future.

The location of 0 degrees N, 0 degrees E. It is tempting to let 0/0 indicate that there is no such station, but such assumptions can be dangerous.

When defining the test case, a part of me wanted to skip the check for coordinatues. That feeling is a very good reason to out extra focus on that test.