Arcade negative Buffer returns null

[Jan62]

I am trying to create a negative Buffer in Arcade to query features inside, as it was possible in older versions (2022). When I execute it noch for example in the Arcade Playground "null" is returned instead of a shrink polygon.

To reproduce open the Arcade Playground https://developers.arcgis.com/arcade/playground/  and insert

var poly = Polygon(
  {
    rings: [
      [
        Point(
          {
            x: -97.06138,
            y: 32.837,
            z: 100,
            hasZ: true,
            spatialReference: { wkid: 3857 }
          }
        ),
        Point(
          {
            x: -97.06133,
            y: 32.836,
            z: 50,
            hasZ: true,
            spatialReference: { wkid: 3857 }
          }
        ),
        Point(
          {
            x: -97.06124,
            y: 32.834,
            z: 20,
            hasZ: true,
            spatialReference: { wkid: 3857 }
          }
        ),
        Point(
          {
            x: -97.06127,
            y: 32.832,
            z: 0,
            hasZ: true,
            spatialReference: { wkid: 3857 }
          }
        )
      ]
    ],
    hasZ: true,
    spatialReference: { wkid: 3857 }
  }
);

Buffer(poly, -10) //return null
//BufferGeodetic(poly, -10) //return null

 Is this a bug or intention?

[DanPatterson]

not sure about arcade but most polygon geometry usually has a duplicate first and last point, what you have given could be interpreted as a polyline

[Jan62]

Yes but it's the example polygon of the Arcade Playground. The result is also null if i add the first point at the end.

[DanPatterson · Accepted solution]

then the buffer size is too large relative to the size of the polygon (eg. bigger than its extent)

[Jan62]

Yeah you are right the polygon was to small. (why is the default playground polygon so small?). This was also the error for the "Attribute Rule" I wanted to save. If the buffer is -1 (meters), the verification of the arcade statement fails. Under -0.3 the expression is valid.

Wich polygon is used for the statement verification in attribute rules in Pro 3.3?

[DanPatterson]

It would be prudent to calculate the poly extent in planar coordinates prior to trying a negative buffer.  At least the extent would give you the ability to assess other values like perimeter, area and other possible measures.