Simplify fix

[stebogit]

Fixes #555

• used @turf/clean-coords (instead of suggested patch)
• added (previously) failing tests.
• extended support of any GeoJSON
• refactored code, updated bench.js and test.js to current standard

[DenisCarriere]

This isn't correct, the ): Geoms is saying that the output is FeatureCollection/Feature/Geometry when in fact it should be the same as the Input defined in Geoms.

The previous definition was a mess! :)

But here's an updated one:

declare function simplify<T extends Geoms>(
  geojson: T,
  tolerance?: number,
  highQuality?: boolean): T;

Which means whatever you enter as T will be the same for the output.

[DenisCarriere]

Another catch would be to include more robust Typescript testing in types.ts.

One day I'll write a guide for using Typescript with TurfJS

This would fail:

import {polygon, Polygon} from '@turf/helpers'
import * as simplify from './'

const poly = polygon([[[0, 0], [10, 10], [20, 20], [0, 0]]]);
const simplifiedPoly: Polygon = simplify(poly);

With the following error:

[ts]
Type 'Geoms' is not assignable to type 'Feature<Polygon>'.
  Type 'GeometryObject' is not assignable to type 'Feature<Polygon>'.
    Types of property 'type' are incompatible.
      Type 'string' is not assignable to type '"Feature"'.

[DenisCarriere]

Way better to support all GeoJSON types 👍

[DenisCarriere]

👍 Agreed

[DenisCarriere]

Try including past contributors to this list when updating modules (@tmcw was heavily involved in the initial development of this module).

Click the history button on the index.js file.
/~https://github.com/Turfjs/turf/commits/b360f9beeec921c38468062fce893158e4a84988/packages/turf-simplify/index.js

[DenisCarriere]

These tests look so much nicer now!! 😄

[DenisCarriere]

Looks great!

[DenisCarriere]

@stebogit Seems like this would benefit from having a mutate param since right now this module is stripping off any extra properties from the FeatureCollection or Features (ex: id, bbox or any custom properties).

We could include clone at the beginning and leverage geomEach to handle the simplify transformations.

[DenisCarriere]

Added test cases for bbox & id removal.

Failing:

• bbox
• id

test('simplify -- removes ID & BBox from properties', t => {
    const properties = {foo: 'bar'};
    const id = 12345;
    const bbox = [0, 0, 2, 2];
    const poly = polygon([[[0, 0], [2, 2], [2, 0], [0, 0]]], properties, bbox, id);
    const simple = simplify(poly, 0.1);

    t.equal(simple.id, id);
    t.deepEqual(simple.bbox, bbox);
    t.deepEqual(simple.properties, properties);
    t.end();
});

[DenisCarriere]

@stebogit You'll have to take a lot at it again to see if everything is ok, I've done some pretty drastic changes.

[stebogit]

It seems you got it all done @DenisCarriere 😜 👍

[DenisCarriere]

Woot! 🤓