review feedback

package.json

@@ -140,6 +140,7 @@
     "@loaders.gl/json": "^2.3.1",
     "@slack/webhook": "^5.0.0",
     "@storybook/addons": "^6.0.16",
+    "@turf/along": "6.0.1",
     "@turf/area": "6.0.1",
     "@turf/bbox": "6.0.1",
     "@turf/bbox-polygon": "6.0.1",

x-pack/plugins/maps/common/get_centroid_features.test.ts

@@ -75,6 +75,7 @@ test('should not create centroid for too many features polygon', () => {
 test('should create centroid feature for line (even number of points)', () => {
   const lineFeature: Feature = {
     type: 'Feature',
+    id: 'myfeature',
     geometry: {
       type: 'LineString',
       coordinates: [
@@ -97,9 +98,10 @@ test('should create centroid feature for line (even number of points)', () => {
   expect(centroidFeatures.length).toBe(1);
   expect(centroidFeatures[0]).toEqual({
     type: 'Feature',
+    id: 'myfeature',
     geometry: {
       type: 'Point',
-      coordinates: [103.0, 1.0],
+      coordinates: [103.50003808007737, 0.5000190382261022],
     },
     properties: {
       __kbn_is_centroid_feature__: true,
@@ -179,7 +181,7 @@ test('should create centroid feature for multi line', () => {
     type: 'Feature',
     geometry: {
       type: 'Point',
-      coordinates: [30, 30],
+      coordinates: [35.56701982106548, 24.717594944805672],
     },
     properties: {
       __kbn_is_centroid_feature__: true,

x-pack/plugins/maps/common/get_centroid_features.ts

@@ -13,6 +13,7 @@ import {
   MultiPolygon,
   Position,
 } from 'geojson';
+import turfAlong from '@turf/along';
 import turfArea from '@turf/area';
 // @ts-expect-error
 import turfCenterOfMass from '@turf/center-of-mass';
@@ -36,7 +37,7 @@ export function getCentroidFeatures(featureCollection: FeatureCollection): Featu
 
     let centroidGeometry: Geometry | null = null;
     if (feature.geometry.type === GEO_JSON_TYPE.LINE_STRING) {
-      centroidGeometry = getLineCentroid((feature.geometry as LineString).coordinates);
+      centroidGeometry = getLineCentroid(feature);
     } else if (feature.geometry.type === GEO_JSON_TYPE.MULTI_LINE_STRING) {
       const coordinates = (feature.geometry as MultiLineString).coordinates;
       let longestLine = coordinates[0];
@@ -49,7 +50,7 @@ export function getCentroidFeatures(featureCollection: FeatureCollection): Featu
           longestLength = nextLength;
         }
       }
-      centroidGeometry = getLineCentroid(longestLine);
+      centroidGeometry = getLineCentroid(lineString(longestLine));
     } else if (feature.geometry.type === GEO_JSON_TYPE.POLYGON) {
       centroidGeometry = turfCenterOfMass(feature).geometry;
     } else if (feature.geometry.type === GEO_JSON_TYPE.MULTI_POLYGON) {
@@ -69,7 +70,8 @@ export function getCentroidFeatures(featureCollection: FeatureCollection): Featu
 
     if (centroidGeometry) {
       centroidFeatures.push({
-        ...feature,
+        type: 'Feature',
+        id: feature.id,
         properties: {
           ...feature.properties,
           [KBN_IS_CENTROID_FEATURE]: true,
@@ -81,11 +83,7 @@ export function getCentroidFeatures(featureCollection: FeatureCollection): Featu
   return centroidFeatures;
 }
 
-// To ensure centroid is placed on line and fast calculations, centroid is middle point
-function getLineCentroid(lineCoordinates: Position[]): Geometry {
-  const centerPointIndex = Math.ceil(lineCoordinates.length / 2) - 1;
-  return {
-    type: GEO_JSON_TYPE.POINT as 'Point',
-    coordinates: lineCoordinates[centerPointIndex],
-  };
+function getLineCentroid(lineStringFeature: LineString): Geometry {
+  const length = turfLength(lineStringFeature);
+  return turfAlong(lineStringFeature, length / 2).geometry;
 }

yarn.lock

@@ -4329,6 +4329,17 @@
   dependencies:
     "@babel/runtime" "^7.10.2"
 
+"@turf/[email protected]":
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/@turf/along/-/along-6.0.1.tgz#595cecdc48fc7fcfa83c940a8e3eb24d4c2e04d4"
+  integrity sha512-6PptAcrsFR3o0Flpktk8Vo68W2txEVTh14zjoTVu+H5docd2+pv5/upA77bg3YFBoJgAxmUFt1leDdjReJ44BQ==
+  dependencies:
+    "@turf/bearing" "6.x"
+    "@turf/destination" "6.x"
+    "@turf/distance" "6.x"
+    "@turf/helpers" "6.x"
+    "@turf/invariant" "6.x"
+
 "@turf/[email protected]":
   version "6.0.1"
   resolved "https://registry.yarnpkg.com/@turf/area/-/area-6.0.1.tgz#50ed63c70ef2bdb72952384f1594319d94f3b051"
@@ -4352,6 +4363,14 @@
     "@turf/helpers" "6.x"
     "@turf/meta" "6.x"
 
+"@turf/[email protected]":
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/@turf/bearing/-/bearing-6.0.1.tgz#8da5d17092e571f170cde7bfb2e5b0d74923c92d"
+  integrity sha512-mXY1NozqV9EFfBTbUItujwfqfQF0G/Xe2fzvnZle90ekPEUfhi4Dgf5JswJTd96J9LiT8kcd6Jonp5khnx0wIg==
+  dependencies:
+    "@turf/helpers" "6.x"
+    "@turf/invariant" "6.x"
+
 "@turf/[email protected]":
   version "6.0.1"
   resolved "https://registry.yarnpkg.com/@turf/boolean-contains/-/boolean-contains-6.0.1.tgz#c3c583215fc5bda47ede51cf52d735ffdc1006a5"
@@ -22657,7 +22676,7 @@ puppeteer@^2.0.0:
   integrity sha512-I4JbNmQHZkE72TPNdipND8GnsEBnqzuksxPSAT25qvudShuuzdY9TwNBQ65IJwPD/pjlpx7fUIUmFyvTHwlxhQ==
   dependencies:
     debug "^4.1.0"
-    devtools-protocol "0.0.818844"
+    devtools-protocol "0.0.809251"
     extract-zip "^2.0.0"
     https-proxy-agent "^4.0.0"
     node-fetch "^2.6.1"