BooleanContains should return false when the Outer contains all the verticies of the Inner, but their borders intersect.

Given two polygons, Outer and Inner, we are checking that booleanContains(outer, inner) should return the correct result.

Consider the case where Outer contains all of the verticies of Inner, but their boundaries intersect. booleanContains incorrectly returns false in such a scenario.

Here is a picture of an example case:

As well as a unit test showing the failing case.

import booleanContains from "@turf/boolean-contains"

describe('booleanContains', () => {

  it('Contains should be false when borders intersect but all verticies are contained', () => {

    // Outer: A 2 x 2 square with the top-right quadrant removed.
    const outer = {
      type: "Polygon",
      coordinates: [[
        [0, 0],
        [0, 2],
        [1, 2],
        [1, 1],
        [2, 1],
        [2, 0],
        [0, 0]
      ]]
    };

    // Inner: A triangle with all 3 verticies inside outer, but one segment intersecting the border of outer
    const inner = {
      type: "Polygon",
      coordinates: [[
        [.1, .1],
        [.1, 1.9],
        [1.9, .1],
        [.1, .1]
      ]]
    }

    expect(booleanContains(outer, inner)).toBe(false) // Returns true
  })
});

Result:

  ● booleanContains › Contains should be false when borders intersect but all verticies are contained

    expect(received).toBe(expected) // Object.is equality

    Expected: false
    Received: true

      89 |     }
      90 | 
    > 91 |     expect(booleanContains(outer, inner)).toBe(false)
         |                                           ^
      92 |   })
      93 | });
      94 | 

Start at the booleanContains entry point and reproduce the supplied polygon case as a unit test. Compare the returned result with the expected false value, then run the booleanContains test suite and confirm the regression case passes.