[ZIP] Missing Features when exporting FeatureCollection of Feature<Polygon> and Feature<MultiPolygon>

[juliolopeztorres]

Hi there!

First of all, thank you for your library and for sharing the code. I am trying to export a given geojson coming from Turf JS in to a Shapefile project as a zip.

I am facing a problem when comparing results in QGis. The thing is that, as far as I can see in the code, POLYGON and MULTIPOLYGON collapse to the same Type, so the final file per type written into the temporary zip object shares its name (path), overwriting its content if some other file would have been generated previously with the same type (i. e.: Polygon and MultiPolygon).

An example of a geojson I am plugging in to the zip() method:

GeoJson example

{
  "type": "FeatureCollection",
    "features": [
    {
      "type": "Feature",
      "properties": {
        "region": "Europe",
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -5.25705141,
              35.964
            ],
            [
              -5.25,
              35.964
            ],
            [
              -5.25,
              36.02001499
            ],
            [
              -5.25705141,
              36.018782780352815
            ],
            [
              -5.25705141,
              35.964
            ]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "region": "Europe",
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -5.32906581,
              35.89872500745445
            ],
            [
              -5.3283905,
              35.89872015
            ],
            [
              -5.32839013,
              35.89871978
            ],
            [
              -5.32752954,
              35.89788818
            ],
            [
              -5.3267498,
              35.89788818
            ],
            [
              -5.32674976,
              35.89788815
            ],
            [
              -5.32674951,
              35.89788815
            ],
            [
              -5.32632062,
              35.89749971
            ],
            [
              -5.32589023,
              35.89711014
            ],
            [
              -5.32561911,
              35.89710003
            ],
            [
              -5.32505989,
              35.89707947
            ],
            [
              -5.32505957,
              35.89707915
            ],
            [
              -5.3250595,
              35.89707915
            ],
            [
              -5.32491102,
              35.89693043
            ],
            [
              -5.3238101,
              35.89582825
            ],
            [
              -5.32378006,
              35.89496994
            ],
            [
              -5.32211018,
              35.89336014
            ],
            [
              -5.32215371,
              35.89289092
            ],
            [
              -5.3221895,
              35.89250215
            ],
            [
              -5.32178242,
              35.89216103
            ],
            [
              -5.3217204,
              35.89210915
            ],
            [
              -5.32092496,
              35.8920943
            ],
            [
              -5.32005978,
              35.8920784
            ],
            [
              -5.32005954,
              35.89207815
            ],
            [
              -5.3200595,
              35.89207815
            ],
            [
              -5.319985811834431,
              35.892
            ],
            [
              -5.315118920724042,
              35.892
            ],
            [
              -5.3150605,
              35.89205915
            ],
            [
              -5.31506031,
              35.89205915
            ],
            [
              -5.31506014,
              35.89205933
            ],
            [
              -5.31166983,
              35.89205933
            ],
            [
              -5.31002998,
              35.89374924
            ],
            [
              -5.30991324,
              35.893745
            ],
            [
              -5.3091895,
              35.89371915
            ],
            [
              -5.3079705,
              35.89500015
            ],
            [
              -5.3079705,
              35.89580915
            ],
            [
              -5.30743964,
              35.89634808
            ],
            [
              -5.30671978,
              35.89707947
            ],
            [
              -5.3062013,
              35.89709926
            ],
            [
              -5.3059205,
              35.89711015
            ],
            [
              -5.30460978,
              35.8983309
            ],
            [
              -5.30463982,
              35.90164185
            ],
            [
              -5.3046395,
              35.90164215
            ],
            [
              -5.30332994,
              35.90291977
            ],
            [
              -5.30332989,
              35.90291977
            ],
            [
              -5.3033295,
              35.90292015
            ],
            [
              -5.30270023,
              35.90289482
            ],
            [
              -5.30255985,
              35.90288925
            ],
            [
              -5.30085993,
              35.90457916
            ],
            [
              -5.3000005,
              35.90457916
            ],
            [
              -5.2991905,
              35.90541815
            ],
            [
              -5.29919028,
              35.90541815
            ],
            [
              -5.29919004,
              35.9054184
            ],
            [
              -5.29750037,
              35.90544128
            ],
            [
              -5.29713854,
              35.90579353
            ],
            [
              -5.29666996,
              35.90625
            ],
            [
              -5.29666966,
              35.90624999
            ],
            [
              -5.2966695,
              35.90625015
            ],
            [
              -5.29615852,
              35.90624031
            ],
            [
              -5.29506015,
              35.90621948
            ],
            [
              -5.2941695,
              35.90705915
            ],
            [
              -5.29240879,
              35.90709436
            ],
            [
              -5.29171991,
              35.90710831
            ],
            [
              -5.29171977,
              35.90710814
            ],
            [
              -5.29171951,
              35.90710815
            ],
            [
              -5.2909395,
              35.90625015
            ],
            [
              -5.29038709,
              35.90624019
            ],
            [
              -5.28921986,
              35.90621948
            ],
            [
              -5.28921952,
              35.90621915
            ],
            [
              -5.28874029,
              35.90573954
            ],
            [
              -5.28800011,
              35.90499878
            ],
            [
              -5.28797007,
              35.90419006
            ],
            [
              -5.28716939,
              35.90341601
            ],
            [
              -5.2871095,
              35.90335815
            ],
            [
              -5.2871395,
              35.90250015
            ],
            [
              -5.28696236,
              35.90232695
            ],
            [
              -5.28669023,
              35.90206146
            ],
            [
              -5.28255987,
              35.90206146
            ],
            [
              -5.2825595,
              35.90206115
            ],
            [
              -5.2825543,
              35.9020566
            ],
            [
              -5.28211021,
              35.90166855
            ],
            [
              -5.28211021,
              35.89916992
            ],
            [
              -5.2829395,
              35.8983311
            ],
            [
              -5.2829195,
              35.89746815
            ],
            [
              -5.28463951,
              35.89582815
            ],
            [
              -5.2846695,
              35.89497015
            ],
            [
              -5.2850795,
              35.89458115
            ],
            [
              -5.28507963,
              35.89458115
            ],
            [
              -5.28507996,
              35.89458084
            ],
            [
              -5.28755981,
              35.89458084
            ],
            [
              -5.29014065774866,
              35.892
            ],
            [
              -5.25705141,
              35.892
            ],
            [
              -5.25705141,
              35.964
            ],
            [
              -5.32906581,
              35.964
            ],
            [
              -5.32906581,
              35.89872500745445
            ]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "region": "Europe",
      },
      "geometry": {
        "type": "MultiPolygon",
        "coordinates": [
          [
            [
              [
                -5.32906581,
                35.84148820946186
              ],
              [
                -5.3233965,
                35.84125315
              ],
              [
                -5.3079765,
                35.83853015
              ],
              [
                -5.2923065,
                35.83543815
              ],
              [
                -5.2869755,
                35.83187215
              ],
              [
                -5.2756285,
                35.82661915
              ],
              [
                -5.2727085,
                35.82515815
              ],
              [
                -5.263613494906775,
                35.82
              ],
              [
                -5.25705141,
                35.82
              ],
              [
                -5.25705141,
                35.892
              ],
              [
                -5.29014065774866,
                35.892
              ],
              [
                -5.29089051,
                35.89125015
              ],
              [
                -5.2923741,
                35.89122381
              ],
              [
                -5.29258013,
                35.89122009
              ],
              [
                -5.29317058,
                35.8906568
              ],
              [
                -5.29341951,
                35.89041915
              ],
              [
                -5.2934197,
                35.89041914
              ],
              [
                -5.29341984,
                35.89041901
              ],
              [
                -5.29365992,
                35.89041018
              ],
              [
                -5.29425035,
                35.89038815
              ],
              [
                -5.29508018,
                35.88957977
              ],
              [
                -5.29870738,
                35.889602
              ],
              [
                -5.3000595,
                35.88961015
              ],
              [
                -5.3008895,
                35.88872115
              ],
              [
                -5.3024995,
                35.88874815
              ],
              [
                -5.3035228,
                35.88774329
              ],
              [
                -5.3042202,
                35.88705826
              ],
              [
                -5.30422039,
                35.88705826
              ],
              [
                -5.3042205,
                35.88705815
              ],
              [
                -5.30589008,
                35.88708114
              ],
              [
                -5.30623128,
                35.88671407
              ],
              [
                -5.3067195,
                35.88618815
              ],
              [
                -5.30793271,
                35.88621149
              ],
              [
                -5.30833006,
                35.88621903
              ],
              [
                -5.30921984,
                35.88542175
              ],
              [
                -5.31168985,
                35.88542175
              ],
              [
                -5.31170936,
                35.885401
              ],
              [
                -5.3124995,
                35.88455915
              ],
              [
                -5.3150605,
                35.88460915
              ],
              [
                -5.31559188,
                35.8850929
              ],
              [
                -5.3159198,
                35.88539117
              ],
              [
                -5.31603599,
                35.88539871
              ],
              [
                -5.31668997,
                35.88544083
              ],
              [
                -5.31841993,
                35.88708115
              ],
              [
                -5.32250023,
                35.88711166
              ],
              [
                -5.32339001,
                35.88621903
              ],
              [
                -5.32422018,
                35.88621903
              ],
              [
                -5.32499566,
                35.88550035
              ],
              [
                -5.3250595,
                35.88544115
              ],
              [
                -5.32505954,
                35.88544115
              ],
              [
                -5.32505989,
                35.88544083
              ],
              [
                -5.32589006,
                35.88544083
              ],
              [
                -5.32788045,
                35.88344015
              ],
              [
                -5.32906581,
                35.88224820415134
              ],
              [
                -5.32906581,
                35.84148820946186
              ]
            ]
          ],
          [
            [
              [
                -5.319985811834431,
                35.892
              ],
              [
                -5.31998353,
                35.89199758
              ],
              [
                -5.31925016,
                35.89122015
              ],
              [
                -5.3188608,
                35.8912236
              ],
              [
                -5.31585979,
                35.89125061
              ],
              [
                -5.31522392,
                35.89189369
              ],
              [
                -5.315118920724042,
                35.892
              ],
              [
                -5.319985811834431,
                35.892
              ]
            ]
          ]
        ]
      }
    },
  ]
}

Code references:

Type mapping
File name setting

My question is:

• Is this a bug or is it the way the library is supposed to work?

I would expect as a result of executing zip() just one set of files (.dbf, .prj, .shp, .shx) inside a .zip.

Checking the library code, multiple sets of files (.dbf, .prj, .shp, .shx) would be generated depending on the geojson feature types, effectively dividing its content. I think that this behavior is a bit weird.

• Could you please confirm or assist on how I can get just one set of files (.dbf, .prj, .shp, .shx) in a .zip representing the entire geojson original content?

In a GeoServer instance using WFS\GetFeature, that is what is returned (.dbf contains all features properties).

Example on TS

zip<'blob'>(geojson, {outputType: 'blob', compression: 'STORE'})
  .then((blob) => {
    const anchor = document.createElement('a')
    document.body.appendChild(anchor)
    anchor.style.display = 'none'
    anchor.href = URL.createObjectURL(blob)
    anchor.download = `exampleGeoJsonToShapefile.zip`
    anchor.click()
    document.body.removeChild(anchor)
  })
  .catch((error) => console.log('error', error))

[stenon-olivier]

Maintainers, any comment on this issue? I see the same problem.