From 3f3f203c8442e462f41273cc514c18c6d4079a86 Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Sat, 26 Aug 2023 13:01:24 +1000
Subject: [PATCH 1/3] Allow user to pass an optional ellipsoid definition to
 distance(), and if they do perform an ellipsoidal distance calculation rather
 than the default great circle.

---
 packages/turf-distance/index.ts     | 103 +++++++-
 packages/turf-distance/package.json |   2 +
 packages/turf-distance/test.js      |  40 +++-
 packages/turf-helpers/index.ts      |  13 ++
 packages/turf-helpers/package.json  |   2 +
 packages/turf-length/index.ts       |   3 +-
 packages/turf-length/test.js        | 348 ++++++++++++++++++++++++++++
 yarn.lock                           |  10 +
 8 files changed, 516 insertions(+), 5 deletions(-)

diff --git a/packages/turf-distance/index.ts b/packages/turf-distance/index.ts
index 7f8176578a..dfee90be94 100644
--- a/packages/turf-distance/index.ts
+++ b/packages/turf-distance/index.ts
@@ -1,13 +1,61 @@
 import { Point } from "geojson";
 import { getCoord } from "@turf/invariant";
-import { radiansToLength, degreesToRadians, Coord, Units } from "@turf/helpers";
+import {
+  radiansToLength,
+  degreesToRadians,
+  datums,
+  Coord,
+  Datum,
+  Units,
+  convertLength,
+} from "@turf/helpers";
+const LatLon = require("geodesy").LatLonEllipsoidal;
 
 //http://en.wikipedia.org/wiki/Haversine_formula
 //http://www.movable-type.co.uk/scripts/latlong.html
 
+/**
+ * Calculates the distance between two {@link Point|points}.
+ * If a specific datum is passed, uses a geodesic ellipsoid calculation.
+ * If no datum is passed, performs a great circle calculation.
+ *
+ * @name distance
+ * @param {Coord | Point} from origin point or coordinate
+ * @param {Coord | Point} to destination point or coordinate
+ * @param {Object} [options={}] Optional parameters
+ * @param {string} [options.units='kilometers'] can be degrees, radians, miles, or kilometers
+ * @param {Datum} [options.datum=datums.WGS84] datum listed in {@link Helpers}
+ * @returns {number} distance between the two points in chosen units
+ * @example
+ * var from = turf.point([-75.343, 39.984]);
+ * var to = turf.point([-75.534, 39.123]);
+ *
+ * var options = {units: 'miles'};
+ * var distance = turf.distance(from, to, options);
+ *
+ * //addToMap
+ * var addToMap = [from, to];
+ * from.properties.distance = distance;
+ * to.properties.distance = distance;
+ */
+function distance(
+  from: Coord | Point,
+  to: Coord | Point,
+  options: {
+    units?: Units;
+    datum?: Datum;
+  } = {}
+) {
+  if (options?.datum) {
+    return geodesic_ellipsoid_distance(from, to, options);
+  } else {
+    return great_circle_distance(from, to, options);
+  }
+}
+
 /**
  * Calculates the distance between two {@link Point|points} in degrees, radians, miles, or kilometers.
- * This uses the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature.
+ * Performs a great circle calculation using the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature.
  *
  * @name distance
  * @param {Coord | Point} from origin point or coordinate
@@ -27,7 +75,7 @@ import { radiansToLength, degreesToRadians, Coord, Units } from "@turf/helpers";
  * from.properties.distance = distance;
  * to.properties.distance = distance;
  */
-function distance(
+function great_circle_distance(
   from: Coord | Point,
   to: Coord | Point,
   options: {
@@ -51,4 +99,53 @@ function distance(
   );
 }
 
+/**
+ * Calculates the distance between two {@link Point|points}.
+ * Performs a geodesic ellipsoid calculation using [Vincenty's formulae](https://en.wikipedia.org/wiki/Vincenty%27s_formulae) to account for speroidal curvature.
+ *
+ * @name geodesic_ellipsoid_distance
+ * @param {Coord | Point} from origin point or coordinate
+ * @param {Coord | Point} to destination point or coordinate
+ * @param {Object} [options={}] Optional parameters
+ * @param {string} [options.units='kilometers'] can be degrees, radians, miles, or kilometers
+ * @param {Datum} [options.datum=datums.WGS84] datum listed in {@link Helpers}
+ * @returns {number} distance between the two points in chosen units
+ * @example
+ * var from = turf.point([-75.343, 39.984]);
+ * var to = turf.point([-75.534, 39.123]);
+ * var options = {units: 'miles', datum: datums.WGS84};
+ *
+ * var distance = turf.distance(from, to, options);
+ *
+ * //addToMap
+ * var addToMap = [from, to];
+ * from.properties.distance = distance;
+ * to.properties.distance = distance;
+ */
+function geodesic_ellipsoid_distance(
+  from: Coord | Point,
+  to: Coord | Point,
+  options: {
+    units?: Units;
+    datum?: Datum;
+  } = {}
+) {
+  const fromCoord = getCoord(from);
+  const toCoord = getCoord(to);
+  const fromLatLon = new LatLon(fromCoord[1], fromCoord[0]);
+  const toLatLon = new LatLon(toCoord[1], toCoord[0]);
+
+  if (options?.datum) {
+    // datum on from point sets the tone.
+    fromLatLon.datum = options.datum;
+  } else {
+    fromLatLon.datum = datums.WGS84;
+  }
+
+  const meters = fromLatLon.distanceTo(toLatLon);
+  // geodesy lib result is in meters
+  return convertLength(meters, "meters", options.units);
+}
+
+export { great_circle_distance, geodesic_ellipsoid_distance };
 export default distance;
diff --git a/packages/turf-distance/package.json b/packages/turf-distance/package.json
index c7a424b99d..a219238f63 100644
--- a/packages/turf-distance/package.json
+++ b/packages/turf-distance/package.json
@@ -47,6 +47,7 @@
     "test:tape": "tsx test.js"
   },
   "devDependencies": {
+    "@types/geodesy": "1.1.3",
     "@types/tape": "*",
     "benchmark": "*",
     "load-json-file": "*",
@@ -60,6 +61,7 @@
   "dependencies": {
     "@turf/helpers": "^7.0.0-alpha.0",
     "@turf/invariant": "^7.0.0-alpha.0",
+    "geodesy": "1.1.3",
     "tslib": "^2.3.0"
   }
 }
diff --git a/packages/turf-distance/test.js b/packages/turf-distance/test.js
index 371dc5ea54..7a00755d7b 100644
--- a/packages/turf-distance/test.js
+++ b/packages/turf-distance/test.js
@@ -3,7 +3,7 @@ const path = require("path");
 const test = require("tape");
 const load = require("load-json-file");
 const write = require("write-json-file");
-const { point } = require("@turf/helpers");
+import { datums, point } from "@turf/helpers";
 const distance = require("./index").default;
 
 const directories = {
@@ -56,3 +56,41 @@ test("distance -- throws", (t) => {
   );
   t.end();
 });
+
+test("distance -- Issue #1726 line between poles", (t) => {
+  const p1 = point([-33.6, 81.1]);
+  const p2 = point([64.5, -80.8]);
+
+  let overallDistance = distance(p1, p2, {
+    units: "meters",
+    datum: datums.WGS84,
+  });
+
+  const expected = 18682436.875; // m from QGIS
+  const tolerance = 0.01; // 1 cm expressed as m
+  t.true(
+    Math.abs(overallDistance - expected) < tolerance,
+    `${overallDistance} within ${tolerance} of ${expected}`
+  );
+
+  t.end();
+});
+
+test("distance -- Issue #1726 line near equator", (t) => {
+  const p1 = point([34, 15.9]);
+  const p2 = point([21, 0.2]);
+
+  let overallDistance = distance(p1, p2, {
+    units: "meters",
+    datum: datums.WGS84,
+  });
+
+  const expected = 2248334.18; // m from QGIS
+  const tolerance = 1; // 1 cm expressed as m
+  t.true(
+    Math.abs(overallDistance - expected) < tolerance,
+    `${overallDistance} within ${tolerance} of ${expected}`
+  );
+
+  t.end();
+});
diff --git a/packages/turf-helpers/index.ts b/packages/turf-helpers/index.ts
index be3beb0386..b03f772d39 100644
--- a/packages/turf-helpers/index.ts
+++ b/packages/turf-helpers/index.ts
@@ -14,6 +14,7 @@ import {
   Position,
   GeoJsonProperties,
 } from "geojson";
+import { Datums, LatLonEllipsoidal } from "geodesy";
 
 import { Id } from "./lib/geojson";
 export * from "./lib/geojson";
@@ -115,6 +116,18 @@ export const areaFactors: Record<AreaUnits, number> = {
   yards: 1.195990046,
 };
 
+/**
+ * Common datum and ellipsoid definitions. Re-export verbatim from geodesy.
+ *
+ * @memberof helpers
+ * @type {Object}
+ */
+export const datums: Datums = LatLonEllipsoidal.datum;
+
+// Re-export type from geodesy so clients don't need to refer directly to
+// geodesy types.
+export type { Datum } from "geodesy";
+
 /**
  * Wraps a GeoJSON {@link Geometry} in a GeoJSON {@link Feature}.
  *
diff --git a/packages/turf-helpers/package.json b/packages/turf-helpers/package.json
index 23cb35e05f..f2d8f55d8f 100644
--- a/packages/turf-helpers/package.json
+++ b/packages/turf-helpers/package.json
@@ -54,6 +54,7 @@
     "test:types": "tsc --esModuleInterop --noEmit --strict types.ts"
   },
   "devDependencies": {
+    "@types/geodesy": "1.1.3",
     "@types/tape": "*",
     "benchmark": "*",
     "npm-run-all": "*",
@@ -63,6 +64,7 @@
     "typescript": "*"
   },
   "dependencies": {
+    "geodesy": "1.1.3",
     "tslib": "^2.3.0"
   }
 }
diff --git a/packages/turf-length/index.ts b/packages/turf-length/index.ts
index c956521928..984e41f7ff 100644
--- a/packages/turf-length/index.ts
+++ b/packages/turf-length/index.ts
@@ -1,6 +1,6 @@
 import { Feature, FeatureCollection, GeometryCollection } from "geojson";
 import distance from "@turf/distance";
-import { Units } from "@turf/helpers";
+import { Datum, Units } from "@turf/helpers";
 import { segmentReduce } from "@turf/meta";
 
 /**
@@ -23,6 +23,7 @@ export default function length(
   geojson: Feature<any> | FeatureCollection<any> | GeometryCollection,
   options: {
     units?: Units;
+    datum?: Datum;
   } = {}
 ): number {
   // Calculate distance from 2-vertex line segments
diff --git a/packages/turf-length/test.js b/packages/turf-length/test.js
index 8fb54b1bdb..1ae8719f31 100644
--- a/packages/turf-length/test.js
+++ b/packages/turf-length/test.js
@@ -4,6 +4,8 @@ const path = require("path");
 const load = require("load-json-file");
 const write = require("write-json-file");
 const length = require("./index").default;
+import { datums } from "@turf/helpers";
+import { lineString } from "@turf/turf";
 
 const directories = {
   in: path.join(__dirname, "test", "in") + path.sep,
@@ -27,3 +29,349 @@ test("turf-length", (t) => {
   }
   t.end();
 });
+
+// https://github.com/Turfjs/turf/issues/1726
+// Test case for path included in #1726
+// Need to do this with a specific test (as opposed to one of the test
+// features) because we need to pass an explicit ellipsoid for this test
+// only.
+test("length -- Issue #1726 line from demo", (t) => {
+  const line = lineString([
+    [17.917491, 59.414082],
+    [17.913936, 59.415673],
+    [17.913789, 59.415738],
+    [17.913681, 59.415786],
+    [17.913583, 59.41583],
+    [17.913493, 59.415869],
+    [17.913405, 59.415907],
+    [17.913322, 59.415943],
+    [17.913241, 59.415977],
+    [17.913164, 59.41601],
+    [17.913085, 59.416042],
+    [17.913008, 59.416073],
+    [17.912932, 59.416103],
+    [17.912858, 59.416132],
+    [17.912785, 59.41616],
+    [17.912713, 59.416187],
+    [17.912642, 59.416214],
+    [17.912571, 59.416239],
+    [17.912485, 59.416269],
+    [17.912398, 59.416299],
+    [17.912311, 59.416328],
+    [17.912222, 59.416356],
+    [17.912133, 59.416384],
+    [17.912044, 59.416411],
+    [17.911953, 59.416438],
+    [17.911862, 59.416464],
+    [17.91177, 59.416489],
+    [17.911678, 59.416514],
+    [17.911585, 59.416538],
+    [17.911491, 59.416562],
+    [17.911397, 59.416585],
+    [17.911302, 59.416607],
+    [17.911207, 59.416629],
+    [17.911111, 59.41665],
+    [17.911014, 59.41667],
+    [17.910917, 59.41669],
+    [17.910819, 59.416709],
+    [17.910721, 59.416727],
+    [17.910623, 59.416745],
+    [17.910524, 59.416762],
+    [17.910425, 59.416778],
+    [17.910325, 59.416794],
+    [17.910225, 59.416809],
+    [17.910124, 59.416823],
+    [17.910023, 59.416837],
+    [17.909922, 59.41685],
+    [17.90982, 59.416862],
+    [17.909719, 59.416874],
+    [17.909616, 59.416885],
+    [17.909514, 59.416895],
+    [17.909411, 59.416905],
+    [17.909308, 59.416914],
+    [17.909205, 59.416922],
+    [17.909102, 59.416929],
+    [17.908998, 59.416936],
+    [17.908894, 59.416942],
+    [17.90879, 59.416948],
+    [17.908686, 59.416953],
+    [17.908582, 59.416957],
+    [17.908478, 59.41696],
+    [17.908374, 59.416962],
+    [17.908269, 59.416964],
+    [17.908165, 59.416966],
+    [17.908061, 59.416966],
+    [17.907956, 59.416966],
+    [17.907852, 59.416965],
+    [17.907747, 59.416964],
+    [17.907643, 59.416961],
+    [17.907539, 59.416958],
+    [17.907435, 59.416955],
+    [17.907331, 59.41695],
+    [17.907227, 59.416945],
+    [17.907123, 59.416939],
+    [17.907019, 59.416933],
+    [17.906916, 59.416926],
+    [17.906812, 59.416918],
+    [17.906709, 59.416909],
+    [17.906606, 59.4169],
+    [17.906504, 59.41689],
+    [17.906402, 59.416879],
+    [17.906317, 59.41687],
+    [17.906231, 59.41686],
+    [17.906144, 59.41685],
+    [17.906055, 59.416838],
+    [17.905965, 59.416826],
+    [17.905872, 59.416814],
+    [17.905777, 59.4168],
+    [17.90568, 59.416786],
+    [17.905583, 59.416772],
+    [17.905483, 59.416757],
+    [17.905379, 59.41674],
+    [17.905269, 59.416723],
+    [17.905156, 59.416704],
+    [17.905033, 59.416684],
+    [17.904897, 59.416661],
+    [17.904711, 59.41663],
+    [17.898026, 59.415505],
+    [17.897692, 59.415449],
+    [17.897563, 59.415428],
+    [17.897446, 59.415409],
+    [17.897332, 59.41539],
+    [17.897224, 59.415373],
+    [17.89712, 59.415357],
+    [17.89702, 59.415342],
+    [17.896876, 59.41532],
+    [17.896732, 59.415299],
+    [17.896587, 59.415279],
+    [17.896442, 59.41526],
+    [17.896297, 59.415241],
+    [17.896151, 59.415222],
+    [17.896006, 59.415205],
+    [17.895859, 59.415188],
+    [17.895713, 59.415171],
+    [17.895566, 59.415155],
+    [17.89542, 59.41514],
+    [17.895272, 59.415126],
+    [17.895125, 59.415112],
+    [17.894977, 59.415099],
+    [17.89483, 59.415086],
+    [17.894682, 59.415074],
+    [17.894533, 59.415063],
+    [17.894385, 59.415052],
+    [17.894236, 59.415042],
+    [17.894088, 59.415033],
+    [17.893983, 59.415027],
+    [17.893876, 59.41502],
+    [17.893763, 59.415014],
+    [17.893643, 59.415008],
+    [17.893521, 59.415002],
+    [17.893387, 59.414996],
+    [17.893036, 59.41498],
+    [17.875072, 59.414164],
+    [17.874809, 59.414151],
+    [17.874617, 59.414142],
+    [17.874443, 59.414133],
+    [17.874283, 59.414125],
+    [17.874149, 59.414117],
+    [17.874016, 59.414109],
+    [17.873882, 59.4141],
+    [17.873748, 59.414091],
+    [17.873615, 59.414081],
+    [17.873481, 59.414071],
+    [17.873323, 59.414059],
+    [17.873151, 59.414044],
+    [17.87296, 59.414028],
+    [17.8727, 59.414005],
+    [17.872439, 59.413982],
+    [17.872249, 59.413966],
+    [17.872076, 59.413951],
+    [17.871918, 59.413939],
+    [17.871785, 59.413928],
+    [17.871651, 59.413919],
+    [17.871517, 59.41391],
+    [17.871384, 59.413901],
+    [17.87125, 59.413893],
+    [17.871116, 59.413885],
+    [17.870957, 59.413876],
+    [17.870783, 59.413868],
+    [17.87059, 59.413858],
+    [17.870327, 59.413846],
+    [17.869112, 59.413791],
+    [17.868775, 59.413775],
+    [17.868646, 59.413769],
+    [17.868528, 59.413763],
+    [17.868413, 59.413757],
+    [17.868304, 59.413752],
+    [17.868201, 59.413746],
+    [17.868101, 59.41374],
+    [17.868, 59.413733],
+    [17.867903, 59.413727],
+    [17.867808, 59.41372],
+    [17.867715, 59.413713],
+    [17.867625, 59.413706],
+    [17.867536, 59.413699],
+    [17.867449, 59.413692],
+    [17.867364, 59.413684],
+    [17.867251, 59.413673],
+    [17.867139, 59.413662],
+    [17.867026, 59.413649],
+    [17.866914, 59.413636],
+    [17.866802, 59.413623],
+    [17.86669, 59.413609],
+    [17.866579, 59.413594],
+    [17.866468, 59.413578],
+    [17.866358, 59.413562],
+    [17.866248, 59.413545],
+    [17.866138, 59.413527],
+    [17.866029, 59.413509],
+    [17.86592, 59.41349],
+    [17.865811, 59.41347],
+    [17.865703, 59.41345],
+    [17.865596, 59.413429],
+    [17.865489, 59.413408],
+    [17.865382, 59.413385],
+    [17.865277, 59.413363],
+    [17.865171, 59.413339],
+    [17.865066, 59.413315],
+    [17.864962, 59.41329],
+    [17.864858, 59.413265],
+    [17.864755, 59.413239],
+    [17.864653, 59.413212],
+    [17.864551, 59.413185],
+    [17.86445, 59.413157],
+    [17.864349, 59.413128],
+    [17.864249, 59.413099],
+    [17.86415, 59.413069],
+    [17.864052, 59.413039],
+    [17.863954, 59.413008],
+    [17.863857, 59.412977],
+    [17.863761, 59.412945],
+    [17.863665, 59.412912],
+    [17.863571, 59.412879],
+    [17.863477, 59.412845],
+    [17.863383, 59.412811],
+    [17.863291, 59.412776],
+    [17.8632, 59.41274],
+    [17.863109, 59.412704],
+    [17.863019, 59.412667],
+    [17.86293, 59.41263],
+    [17.862842, 59.412593],
+    [17.862755, 59.412554],
+    [17.862668, 59.412516],
+    [17.862583, 59.412476],
+    [17.862498, 59.412436],
+    [17.862415, 59.412396],
+    [17.862332, 59.412355],
+    [17.862251, 59.412314],
+    [17.86217, 59.412272],
+    [17.86209, 59.41223],
+    [17.862012, 59.412187],
+    [17.861934, 59.412144],
+    [17.861857, 59.4121],
+    [17.861781, 59.412056],
+    [17.861707, 59.412012],
+    [17.861633, 59.411966],
+    [17.861561, 59.411921],
+    [17.861489, 59.411875],
+    [17.861419, 59.411829],
+    [17.86135, 59.411782],
+    [17.861281, 59.411735],
+    [17.861214, 59.411687],
+    [17.861148, 59.411639],
+    [17.861084, 59.41159],
+    [17.86102, 59.411542],
+    [17.860957, 59.411492],
+    [17.860896, 59.411443],
+    [17.860836, 59.411393],
+    [17.860777, 59.411343],
+    [17.860719, 59.411292],
+    [17.860662, 59.411241],
+    [17.860607, 59.41119],
+    [17.860552, 59.411138],
+    [17.860499, 59.411086],
+    [17.860447, 59.411033],
+    [17.860397, 59.410981],
+    [17.860347, 59.410928],
+    [17.860299, 59.410875],
+    [17.860252, 59.410821],
+    [17.860207, 59.410767],
+    [17.860162, 59.410713],
+    [17.860119, 59.410659],
+    [17.860077, 59.410604],
+    [17.860037, 59.410549],
+    [17.859997, 59.410494],
+    [17.859959, 59.410439],
+    [17.859922, 59.410383],
+    [17.859887, 59.410328],
+    [17.859853, 59.410272],
+    [17.85982, 59.410215],
+    [17.859789, 59.410159],
+    [17.859758, 59.410102],
+    [17.85973, 59.410046],
+    [17.859702, 59.409989],
+    [17.859676, 59.409932],
+    [17.859651, 59.409874],
+    [17.859628, 59.409817],
+    [17.859605, 59.409759],
+    [17.859585, 59.409702],
+    [17.859565, 59.409644],
+    [17.859547, 59.409586],
+    [17.85953, 59.409528],
+    [17.859514, 59.409468],
+    [17.859498, 59.409404],
+    [17.859483, 59.409338],
+    [17.859468, 59.409269],
+    [17.859453, 59.409194],
+    [17.859438, 59.409111],
+    [17.859417, 59.408997],
+    [17.858396, 59.403363],
+  ]);
+
+  // console.log(JSON.stringify(featureCollection([line])));
+
+  const overallDistance = length(line, {
+    units: "meters",
+    datum: datums.WGS84,
+  });
+
+  const expected = 4367.078; // m from QGIS
+  const tolerance = 0.02; // 2 cm expressed as m
+  t.true(
+    Math.abs(overallDistance - expected) < tolerance,
+    `${overallDistance} within ${tolerance} of ${expected}`
+  );
+
+  t.end();
+});
+
+// https://github.com/Turfjs/turf/issues/1726
+// Test case for path included in #1726
+// Need to do this with a specific test (as opposed to one of the test
+// features) because we need to pass an explicit ellipsoid for this test
+// only.
+test("length -- Issue #1726 loooong line", (t) => {
+  const line = lineString([
+    [-39, 76],
+    [34, 53],
+    [22, -28],
+    [123, -28],
+    [-6, -75],
+  ]);
+
+  // console.log(JSON.stringify(featureCollection([line])));
+
+  const overallDistance = length(line, {
+    units: "meters",
+    datum: datums.WGS84,
+  });
+
+  const expected = 30555616.0; // m from QGIS
+  const tolerance = 0.02; // 2 cm expressed as m
+  t.true(
+    Math.abs(overallDistance - expected) < tolerance,
+    `${overallDistance} within ${tolerance} of ${expected}`
+  );
+
+  t.end();
+});
diff --git a/yarn.lock b/yarn.lock
index 2e0fc2c34c..3bd97bac58 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2327,6 +2327,11 @@
   resolved "https://registry.yarnpkg.com/@types/events/-/events-3.0.0.tgz#2862f3f58a9a7f7c3e78d79f130dd4d71c25c2a7"
   integrity sha512-EaObqwIvayI5a8dCzhFrjKzVwKLxjoG9T6Ppd5CEo07LRKfQ8Yokw54r5+Wq7FaBQ+yXRvQAYPrHwya1/UFt9g==
 
+"@types/geodesy@1.1.3":
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/@types/geodesy/-/geodesy-1.1.3.tgz#26999ade11f47cada7b529d19e38bba76f164665"
+  integrity sha512-migQ5GRDj53SNVU+HZ8ajxRoPtTWY/vXwvQFP6OIL7WJywtBquRgtHwAUuOS/C+fLNtIi+XixdqghAvT2JeRqA==
+
 "@types/geojson-equality@^0.2.0":
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/@types/geojson-equality/-/geojson-equality-0.2.0.tgz#2c7d411f534bee6bf2e7689c14c4c6f3dced2a8c"
@@ -5108,6 +5113,11 @@ gensync@^1.0.0-beta.1, gensync@^1.0.0-beta.2:
   resolved "https://registry.yarnpkg.com/gensync/-/gensync-1.0.0-beta.2.tgz#32a6ee76c3d7f52d46b2b1ae5d93fea8580a25e0"
   integrity sha512-3hN7NaskYvMDLQY55gnW3NQ+mesEAepTqlg+VEbj7zzqEMBVNhzcGYYeqFo/TlYz6eQiFcp1HcsCZO+nGgS8zg==
 
+geodesy@1.1.3:
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/geodesy/-/geodesy-1.1.3.tgz#a0cbd5db5c0cf8ac045e749f754f61b450382de9"
+  integrity sha512-H/0XSd1KjKZGZ2YGZcOYzRyY/foYAawwTEumNSo+YUwf+u5d4CfvBRg2i2Qimrx9yUEjWR8hLvMnhghuVFN0Zg==
+
 geojson-equality@0.1.6:
   version "0.1.6"
   resolved "https://registry.yarnpkg.com/geojson-equality/-/geojson-equality-0.1.6.tgz#a171374ef043e5d4797995840bae4648e0752d72"

From e6dfbd8e2c800aea60aee0f85259e42c655fa9f7 Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Sun, 3 Sep 2023 22:24:52 +1000
Subject: [PATCH 2/3] Prior commit failed post-commit CI. Identified a problem
 with the final packages/turf/ conversion from mjs to rolled up js. "In strict
 mode code, functions can only be declared at top level or inside a block."

---
 packages/turf-distance/index.ts | 14 +++++++++-----
 packages/turf-distance/test.js  |  2 +-
 packages/turf-helpers/index.ts  | 11 ++++++++---
 packages/turf-length/index.ts   |  2 +-
 4 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/packages/turf-distance/index.ts b/packages/turf-distance/index.ts
index dfee90be94..186b15a58f 100644
--- a/packages/turf-distance/index.ts
+++ b/packages/turf-distance/index.ts
@@ -1,14 +1,15 @@
 import { Point } from "geojson";
 import { getCoord } from "@turf/invariant";
+import type { Coord, Datum, Units } from "@turf/helpers";
 import {
+  datums,
   radiansToLength,
   degreesToRadians,
-  datums,
-  Coord,
-  Datum,
-  Units,
   convertLength,
 } from "@turf/helpers";
+// Unable to find an equivalent import statement that works. Fails when building
+// index.mjs → turf.min.js in packages/turf/
+// import { LatLonEllipsoidal as LatLon } from "geodesy";
 const LatLon = require("geodesy").LatLonEllipsoidal;
 
 //http://en.wikipedia.org/wiki/Haversine_formula
@@ -142,7 +143,10 @@ function geodesic_ellipsoid_distance(
     fromLatLon.datum = datums.WGS84;
   }
 
-  const meters = fromLatLon.distanceTo(toLatLon);
+  // LatLonEllipsoidal types don't properly list all base LatLon functions
+  // e.g. distanceTo. Should be able to remove when we can move to a newer
+  // version of geodesy.
+  const meters = (fromLatLon as any).distanceTo(toLatLon);
   // geodesy lib result is in meters
   return convertLength(meters, "meters", options.units);
 }
diff --git a/packages/turf-distance/test.js b/packages/turf-distance/test.js
index 7a00755d7b..fcc6281302 100644
--- a/packages/turf-distance/test.js
+++ b/packages/turf-distance/test.js
@@ -3,7 +3,7 @@ const path = require("path");
 const test = require("tape");
 const load = require("load-json-file");
 const write = require("write-json-file");
-import { datums, point } from "@turf/helpers";
+const { datums, point } = require("@turf/helpers");
 const distance = require("./index").default;
 
 const directories = {
diff --git a/packages/turf-helpers/index.ts b/packages/turf-helpers/index.ts
index b03f772d39..871d255226 100644
--- a/packages/turf-helpers/index.ts
+++ b/packages/turf-helpers/index.ts
@@ -14,7 +14,11 @@ import {
   Position,
   GeoJsonProperties,
 } from "geojson";
-import { Datums, LatLonEllipsoidal } from "geodesy";
+import type { Datum } from "geodesy";
+// Unable to find an equivalent import statement that works. Fails when building
+// index.mjs → turf.min.js in packages/turf/
+// import { LatLonEllipsoidal as LatLon } from "geodesy";
+const LatLon = require("geodesy").LatLonEllipsoidal;
 
 import { Id } from "./lib/geojson";
 export * from "./lib/geojson";
@@ -122,11 +126,12 @@ export const areaFactors: Record<AreaUnits, number> = {
  * @memberof helpers
  * @type {Object}
  */
-export const datums: Datums = LatLonEllipsoidal.datum;
+const datums = LatLon.datum;
+export { datums };
 
 // Re-export type from geodesy so clients don't need to refer directly to
 // geodesy types.
-export type { Datum } from "geodesy";
+export type { Datum };
 
 /**
  * Wraps a GeoJSON {@link Geometry} in a GeoJSON {@link Feature}.
diff --git a/packages/turf-length/index.ts b/packages/turf-length/index.ts
index 984e41f7ff..a91fa15875 100644
--- a/packages/turf-length/index.ts
+++ b/packages/turf-length/index.ts
@@ -1,6 +1,6 @@
 import { Feature, FeatureCollection, GeometryCollection } from "geojson";
 import distance from "@turf/distance";
-import { Datum, Units } from "@turf/helpers";
+import type { Datum, Units } from "@turf/helpers";
 import { segmentReduce } from "@turf/meta";
 
 /**

From 13d093c87582a011ce1c4af5bd631b9ede81e9b4 Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Thu, 14 Sep 2023 13:19:26 +1000
Subject: [PATCH 3/3] Upgrading to geodesy 2.3.0 (possible now that #2489 is
 merged) meaning we can use import rather than require. Tightened up distance
 module function names and their optional parameters as well.

---
 packages/turf-distance/index.ts     | 48 +++++++++++++----------------
 packages/turf-distance/package.json |  4 +--
 packages/turf-distance/test.js      | 21 ++++++++++++-
 packages/turf-helpers/index.ts      |  7 ++---
 packages/turf-helpers/package.json  |  4 +--
 yarn.lock                           | 16 +++++-----
 6 files changed, 55 insertions(+), 45 deletions(-)

diff --git a/packages/turf-distance/index.ts b/packages/turf-distance/index.ts
index 186b15a58f..4008d1f119 100644
--- a/packages/turf-distance/index.ts
+++ b/packages/turf-distance/index.ts
@@ -7,11 +7,7 @@ import {
   degreesToRadians,
   convertLength,
 } from "@turf/helpers";
-// Unable to find an equivalent import statement that works. Fails when building
-// index.mjs → turf.min.js in packages/turf/
-// import { LatLonEllipsoidal as LatLon } from "geodesy";
-const LatLon = require("geodesy").LatLonEllipsoidal;
-
+import LatLon from "geodesy/latlon-ellipsoidal-vincenty.js";
 //http://en.wikipedia.org/wiki/Haversine_formula
 //http://www.movable-type.co.uk/scripts/latlong.html
 
@@ -48,9 +44,12 @@ function distance(
   } = {}
 ) {
   if (options?.datum) {
-    return geodesic_ellipsoid_distance(from, to, options);
+    return geodesicEllipsoidDistance(from, to, {
+      datum: options.datum, // Must pass a datum option
+      ...options,
+    });
   } else {
-    return great_circle_distance(from, to, options);
+    return greatCircleDistance(from, to, options);
   }
 }
 
@@ -58,7 +57,7 @@ function distance(
  * Calculates the distance between two {@link Point|points} in degrees, radians, miles, or kilometers.
  * Performs a great circle calculation using the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature.
  *
- * @name distance
+ * @name greatCircleDistance
  * @param {Coord | Point} from origin point or coordinate
  * @param {Coord | Point} to destination point or coordinate
  * @param {Object} [options={}] Optional parameters
@@ -69,14 +68,14 @@ function distance(
  * var to = turf.point([-75.534, 39.123]);
  * var options = {units: 'miles'};
  *
- * var distance = turf.distance(from, to, options);
+ * var distance = turf.greatCircleDistance(from, to, options);
  *
  * //addToMap
  * var addToMap = [from, to];
  * from.properties.distance = distance;
  * to.properties.distance = distance;
  */
-function great_circle_distance(
+function greatCircleDistance(
   from: Coord | Point,
   to: Coord | Point,
   options: {
@@ -104,7 +103,7 @@ function great_circle_distance(
  * Calculates the distance between two {@link Point|points}.
  * Performs a geodesic ellipsoid calculation using [Vincenty's formulae](https://en.wikipedia.org/wiki/Vincenty%27s_formulae) to account for speroidal curvature.
  *
- * @name geodesic_ellipsoid_distance
+ * @name geodesicEllipsoidDistance
  * @param {Coord | Point} from origin point or coordinate
  * @param {Coord | Point} to destination point or coordinate
  * @param {Object} [options={}] Optional parameters
@@ -116,40 +115,35 @@ function great_circle_distance(
  * var to = turf.point([-75.534, 39.123]);
  * var options = {units: 'miles', datum: datums.WGS84};
  *
- * var distance = turf.distance(from, to, options);
+ * var distance = turf.geodesicEllipsoidDistance(from, to, options);
  *
  * //addToMap
  * var addToMap = [from, to];
  * from.properties.distance = distance;
  * to.properties.distance = distance;
  */
-function geodesic_ellipsoid_distance(
+function geodesicEllipsoidDistance(
   from: Coord | Point,
   to: Coord | Point,
   options: {
     units?: Units;
-    datum?: Datum;
-  } = {}
+    datum: Datum;
+  } = { datum: datums.WGS84 }
 ) {
   const fromCoord = getCoord(from);
   const toCoord = getCoord(to);
+
+  const datum = options.datum;
+
   const fromLatLon = new LatLon(fromCoord[1], fromCoord[0]);
+  // datum on from point sets the tone.
+  fromLatLon.datum = datum;
   const toLatLon = new LatLon(toCoord[1], toCoord[0]);
 
-  if (options?.datum) {
-    // datum on from point sets the tone.
-    fromLatLon.datum = options.datum;
-  } else {
-    fromLatLon.datum = datums.WGS84;
-  }
-
-  // LatLonEllipsoidal types don't properly list all base LatLon functions
-  // e.g. distanceTo. Should be able to remove when we can move to a newer
-  // version of geodesy.
-  const meters = (fromLatLon as any).distanceTo(toLatLon);
+  const meters = fromLatLon.distanceTo(toLatLon);
   // geodesy lib result is in meters
   return convertLength(meters, "meters", options.units);
 }
 
-export { great_circle_distance, geodesic_ellipsoid_distance };
+export { greatCircleDistance, geodesicEllipsoidDistance };
 export default distance;
diff --git a/packages/turf-distance/package.json b/packages/turf-distance/package.json
index a219238f63..b6edde00af 100644
--- a/packages/turf-distance/package.json
+++ b/packages/turf-distance/package.json
@@ -47,7 +47,7 @@
     "test:tape": "tsx test.js"
   },
   "devDependencies": {
-    "@types/geodesy": "1.1.3",
+    "@types/geodesy": "^2.2.3",
     "@types/tape": "*",
     "benchmark": "*",
     "load-json-file": "*",
@@ -61,7 +61,7 @@
   "dependencies": {
     "@turf/helpers": "^7.0.0-alpha.0",
     "@turf/invariant": "^7.0.0-alpha.0",
-    "geodesy": "1.1.3",
+    "geodesy": "^2.3.0",
     "tslib": "^2.3.0"
   }
 }
diff --git a/packages/turf-distance/test.js b/packages/turf-distance/test.js
index fcc6281302..ee6f645270 100644
--- a/packages/turf-distance/test.js
+++ b/packages/turf-distance/test.js
@@ -5,6 +5,7 @@ const load = require("load-json-file");
 const write = require("write-json-file");
 const { datums, point } = require("@turf/helpers");
 const distance = require("./index").default;
+const { geodesicEllipsoidDistance } = require("./index");
 
 const directories = {
   in: path.join(__dirname, "test", "in") + path.sep,
@@ -86,7 +87,25 @@ test("distance -- Issue #1726 line near equator", (t) => {
   });
 
   const expected = 2248334.18; // m from QGIS
-  const tolerance = 1; // 1 cm expressed as m
+  const tolerance = 0.01; // 1 cm expressed as m
+  t.true(
+    Math.abs(overallDistance - expected) < tolerance,
+    `${overallDistance} within ${tolerance} of ${expected}`
+  );
+
+  t.end();
+});
+
+test("distance -- calling ellipsoid distance with empty options", (t) => {
+  // Make sure calling geodesicEllipsoidDistance directly without a datum
+  // option defaults to WGS84.
+  const p1 = point([-33.6, 81.1]);
+  const p2 = point([64.5, -80.8]);
+
+  let overallDistance = geodesicEllipsoidDistance(p1, p2);
+
+  const expected = 18682.436875; // m from QGIS as km
+  const tolerance = 0.00001; // 1 cm expressed as km
   t.true(
     Math.abs(overallDistance - expected) < tolerance,
     `${overallDistance} within ${tolerance} of ${expected}`
diff --git a/packages/turf-helpers/index.ts b/packages/turf-helpers/index.ts
index 871d255226..40ac26e230 100644
--- a/packages/turf-helpers/index.ts
+++ b/packages/turf-helpers/index.ts
@@ -15,10 +15,7 @@ import {
   GeoJsonProperties,
 } from "geojson";
 import type { Datum } from "geodesy";
-// Unable to find an equivalent import statement that works. Fails when building
-// index.mjs → turf.min.js in packages/turf/
-// import { LatLonEllipsoidal as LatLon } from "geodesy";
-const LatLon = require("geodesy").LatLonEllipsoidal;
+import LatLonEllipsoidalVincenty from "geodesy/latlon-ellipsoidal-vincenty.js";
 
 import { Id } from "./lib/geojson";
 export * from "./lib/geojson";
@@ -126,7 +123,7 @@ export const areaFactors: Record<AreaUnits, number> = {
  * @memberof helpers
  * @type {Object}
  */
-const datums = LatLon.datum;
+const datums = LatLonEllipsoidalVincenty.datums;
 export { datums };
 
 // Re-export type from geodesy so clients don't need to refer directly to
diff --git a/packages/turf-helpers/package.json b/packages/turf-helpers/package.json
index f2d8f55d8f..dea2bcf431 100644
--- a/packages/turf-helpers/package.json
+++ b/packages/turf-helpers/package.json
@@ -54,7 +54,7 @@
     "test:types": "tsc --esModuleInterop --noEmit --strict types.ts"
   },
   "devDependencies": {
-    "@types/geodesy": "1.1.3",
+    "@types/geodesy": "^2.2.3",
     "@types/tape": "*",
     "benchmark": "*",
     "npm-run-all": "*",
@@ -64,7 +64,7 @@
     "typescript": "*"
   },
   "dependencies": {
-    "geodesy": "1.1.3",
+    "geodesy": "^2.3.0",
     "tslib": "^2.3.0"
   }
 }
diff --git a/yarn.lock b/yarn.lock
index 3bd97bac58..359b1d7b5d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2327,10 +2327,10 @@
   resolved "https://registry.yarnpkg.com/@types/events/-/events-3.0.0.tgz#2862f3f58a9a7f7c3e78d79f130dd4d71c25c2a7"
   integrity sha512-EaObqwIvayI5a8dCzhFrjKzVwKLxjoG9T6Ppd5CEo07LRKfQ8Yokw54r5+Wq7FaBQ+yXRvQAYPrHwya1/UFt9g==
 
-"@types/geodesy@1.1.3":
-  version "1.1.3"
-  resolved "https://registry.yarnpkg.com/@types/geodesy/-/geodesy-1.1.3.tgz#26999ade11f47cada7b529d19e38bba76f164665"
-  integrity sha512-migQ5GRDj53SNVU+HZ8ajxRoPtTWY/vXwvQFP6OIL7WJywtBquRgtHwAUuOS/C+fLNtIi+XixdqghAvT2JeRqA==
+"@types/geodesy@^2.2.3":
+  version "2.2.3"
+  resolved "https://registry.yarnpkg.com/@types/geodesy/-/geodesy-2.2.3.tgz#70ff892715cb69607469c50347421151331a9198"
+  integrity sha512-zpgJ6W/PH8nQN5fyiynfRGLa7X9Fij8QuvBzZhN+/63+nrLaj6sLF7KbgKf55HBGryCuyuA8fEB8QUeAFCPWrg==
 
 "@types/geojson-equality@^0.2.0":
   version "0.2.0"
@@ -5113,10 +5113,10 @@ gensync@^1.0.0-beta.1, gensync@^1.0.0-beta.2:
   resolved "https://registry.yarnpkg.com/gensync/-/gensync-1.0.0-beta.2.tgz#32a6ee76c3d7f52d46b2b1ae5d93fea8580a25e0"
   integrity sha512-3hN7NaskYvMDLQY55gnW3NQ+mesEAepTqlg+VEbj7zzqEMBVNhzcGYYeqFo/TlYz6eQiFcp1HcsCZO+nGgS8zg==
 
-geodesy@1.1.3:
-  version "1.1.3"
-  resolved "https://registry.yarnpkg.com/geodesy/-/geodesy-1.1.3.tgz#a0cbd5db5c0cf8ac045e749f754f61b450382de9"
-  integrity sha512-H/0XSd1KjKZGZ2YGZcOYzRyY/foYAawwTEumNSo+YUwf+u5d4CfvBRg2i2Qimrx9yUEjWR8hLvMnhghuVFN0Zg==
+geodesy@^2.3.0:
+  version "2.4.0"
+  resolved "https://registry.yarnpkg.com/geodesy/-/geodesy-2.4.0.tgz#6a0ad3dab3c1f95d8430aaa04fbe620b639c3e48"
+  integrity sha512-tHjQ1sXq8UAIEg1V0Pa6mznUxGU0R+3H5PIF6NULr0yPCAVLKqJro93Bbr19jSE18BMfyjN4osWDI4sm92m0kw==
 
 geojson-equality@0.1.6:
   version "0.1.6"