turf-intersect: new test data with small intersection

[zbyte64]

Had an error in my app: 'Uncaught TopologyException: found non-noded intersection between LINESTRING and LINESTRING', issue #463 recommended creating a test case with the failure and that is what this pull request does. On this branch the intersect tests fail with REGEN=true . The added geojson file defines an intersect geometry only 60 inches wide. #297 (comment) indicates that JSTS has issues with resolution and may be the cause.

[zbyte64]

Attempted to normalize the precision as described: #357 ; issue still persists. Maybe the larger geometry has too many points spanning the small box?

[DenisCarriere]

Looks like there's two polygon outers in your Polygon Feature. The inner ring is outside the outer ring which means it would be an invalid Polygon (might be the reason why jsts is failing).

Moved vertices of the "inner" ring.

[zbyte64]

Is there a function for checking this, like kinks?

[DenisCarriere]

There's unlink polygon that might be useful. https://github.com/Turfjs/turf/blob/master/packages/turf-unkink-polygon/README.md

[zbyte64]

kink doesn't report any kinks. The geometry of the lot is represented as one array in the geojson; how were you able to construct/detect the inner ring?

[DenisCarriere]

Oh wait... the Inner & Outer were two polygon features in a FeatureCollection 🤦‍♂️ my bad.

It does seem to be a valid GeoJSON according to https://www.mapbox.com/geojsonhint

🤔 ... looking into this.

[stebogit]

sorry guys, that typo was driving me crazy 🤣

[DenisCarriere]

@stebogit hilarious!

[DenisCarriere]

@zbyte64 Made a quick patch fix for this issue, seems like the small inner polygon was throwing a topology error in JSTS, when truncating the precision to 4 and removing any duplicate nodes using clean-coords the smaller polygon only had 2 remaining nodes and a valid Polygon needs a minimum of 4 coordinates.

Not an ideal result, but at least it stopped crashing... 👍

🤔 I couldn't send commits to your PR, so I opened a new one here: #1011

[ilijaz]

Terrible. Its break all my code, cause i'm try to use turf in precision farming.
Some micro polygons will to be a points. I'm very excited about #88