Add bicycle triangle factors to Transmodel API

[leonardehrenfried]

Summary

This exposes the bicycle triangle factors in the Transmodel API.

I also took care to return a meaningful error when the factors don't add up to 1. It looks like this:

{
  "data": {},
  "errors": [
    {
      "path": [
        "trip"
      ],
      "errorType": "DataFetchingException",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "message": "Exception while fetching data (/trip) : The values of triangleSafetyFactor, triangleSlopeFactor, and triangleTimeFactor must sum to 1"
    }
  ]
}

Unit tests

Is there a way to write a unit test for this? I'd love to.

Code style

Yes.

Documentation

Yes.

Changelog

Was a bullet point added to the changelog file with description and link to the linked issue?

[gmellemstrand]

I am not sure if others agree with me, but I think I would prefer the assertTriangleParameters method to just normalize the parameters so that they keep the same ratio, but the sum is 1. Just add a log statement whenever this happens instead of throwing an exception.

[leonardehrenfried]

Should this only happen in the Transmodel API or everywhere?

[gmellemstrand]

I think it would be good to do it everywhere, as I don't see that it is transmodel specific in any way.

[leonardehrenfried]

I just saw that a method like that already exists but currently is totally unused:

OpenTripPlanner/src/main/java/org/opentripplanner/routing/api/request/RoutingRequest.java

Line 1340 in 18e44be

public void setTriangleNormalized (double safe, double slope, double time) {

[gmellemstrand]

Looks good! But could division by zero be a problem here?

[leonardehrenfried]

I will write some tests to make sure.

[leonardehrenfried]

@t2gran I've replaced the individual setters of the triangle factor with the call to the method where you have to set all three of them.