From 404a8195a404f5e0e155ba91bca2c15aee150a47 Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Wed, 20 Nov 2024 14:35:19 +1100
Subject: [PATCH 1/5] Implemented a different approach to cleanCoords that
 should work better with lines that retrace or pass back through their origin.
 Note depends on PR #2751 to be merged first as part of the problem was
 booleanPointOnLine misbehaving.

---
 packages/turf-clean-coords/index.ts     | 120 +++++++++---------------
 packages/turf-clean-coords/package.json |   1 +
 packages/turf-clean-coords/test.ts      |  97 +++++++++++++++++++
 pnpm-lock.yaml                          |   3 +
 4 files changed, 143 insertions(+), 78 deletions(-)

diff --git a/packages/turf-clean-coords/index.ts b/packages/turf-clean-coords/index.ts
index 3be8ba3efd..972abe70eb 100644
--- a/packages/turf-clean-coords/index.ts
+++ b/packages/turf-clean-coords/index.ts
@@ -1,6 +1,8 @@
 import { Position } from "geojson";
 import { feature } from "@turf/helpers";
 import { getCoords, getType } from "@turf/invariant";
+import { booleanPointOnLine } from "@turf/boolean-point-on-line";
+import { lineString } from "@turf/helpers";
 
 // To-Do => Improve Typescript GeoJSON handling
 
@@ -99,62 +101,54 @@ function cleanCoords(
  * @returns {Array<number>} Cleaned coordinates
  */
 function cleanLine(line: Position[], type: string) {
-  var points = getCoords(line);
+  const points = getCoords(line);
   // handle "clean" segment
   if (points.length === 2 && !equals(points[0], points[1])) return points;
 
-  var newPoints = [];
-  var secondToLast = points.length - 1;
-  var newPointsLength = newPoints.length;
-
-  newPoints.push(points[0]);
-  for (var i = 1; i < secondToLast; i++) {
-    var prevAddedPoint = newPoints[newPoints.length - 1];
-    if (
-      points[i][0] === prevAddedPoint[0] &&
-      points[i][1] === prevAddedPoint[1]
-    )
-      continue;
-    else {
-      newPoints.push(points[i]);
-      newPointsLength = newPoints.length;
-      if (newPointsLength > 2) {
-        if (
-          isPointOnLineSegment(
-            newPoints[newPointsLength - 3],
-            newPoints[newPointsLength - 1],
-            newPoints[newPointsLength - 2]
-          )
-        )
-          newPoints.splice(newPoints.length - 2, 1);
-      }
+  const newPoints = [];
+
+  // Segments based approach. With initial segment a-b, keep comparing to a
+  // longer segment a-c and as long as b is still on a-c, b is a redundant
+  // point.
+  let a = 0,
+    b = 1,
+    c = 2;
+
+  // Guaranteed we'll use the first point.
+  newPoints.push(points[a]);
+  // While there is still room to extend the segment ...
+  while (c < points.length) {
+    if (booleanPointOnLine(points[b], lineString([points[a], points[c]]))) {
+      // b is on a-c, so we can discard point b, and extend a-b to be the same
+      // as a-c as the basis for comparison during the next iteration.
+      b = c;
+    } else {
+      // b is NOT on a-c, suggesting a-c is not an extension of a-b. Commit a-b
+      // as a necessary segment.
+      newPoints.push(points[b]);
+
+      // Make our a-b for the next iteration start from the end of the segment
+      // that was just locked in i.e. next a-b should be the current b-(b+1).
+      a = b;
+      b++;
+      c = b;
     }
+    // Plan to look at the next point during the next iteration.
+    c++;
   }
-  newPoints.push(points[points.length - 1]);
-  newPointsLength = newPoints.length;
-
-  // (Multi)Polygons must have at least 4 points, but a closed LineString with only 3 points is acceptable
-  if (
-    (type === "Polygon" || type === "MultiPolygon") &&
-    equals(points[0], points[points.length - 1]) &&
-    newPointsLength < 4
-  ) {
-    throw new Error("invalid polygon");
-  }
+  // No remaining points, so commit the current a-b segment.
+  newPoints.push(points[b]);
 
-  if (type === "LineString" && newPointsLength < 3) {
-    return newPoints;
+  // (Multi)Polygons must have at least 4 points and be closed.
+  if (type === "Polygon" || type === "MultiPolygon") {
+    if (!equals(points[0], points[points.length - 1])) {
+      throw new Error("invalid polygon, first and last points not equal");
+    }
+    if (newPoints.length < 4) {
+      throw new Error("invalid polygon, fewer than 4 points");
+    }
   }
 
-  if (
-    isPointOnLineSegment(
-      newPoints[newPointsLength - 3],
-      newPoints[newPointsLength - 1],
-      newPoints[newPointsLength - 2]
-    )
-  )
-    newPoints.splice(newPoints.length - 2, 1);
-
   return newPoints;
 }
 
@@ -170,35 +164,5 @@ function equals(pt1: Position, pt2: Position) {
   return pt1[0] === pt2[0] && pt1[1] === pt2[1];
 }
 
-/**
- * Returns if `point` is on the segment between `start` and `end`.
- * Borrowed from `@turf/boolean-point-on-line` to speed up the evaluation (instead of using the module as dependency)
- *
- * @private
- * @param {Position} start coord pair of start of line
- * @param {Position} end coord pair of end of line
- * @param {Position} point coord pair of point to check
- * @returns {boolean} true/false
- */
-function isPointOnLineSegment(start: Position, end: Position, point: Position) {
-  var x = point[0],
-    y = point[1];
-  var startX = start[0],
-    startY = start[1];
-  var endX = end[0],
-    endY = end[1];
-
-  var dxc = x - startX;
-  var dyc = y - startY;
-  var dxl = endX - startX;
-  var dyl = endY - startY;
-  var cross = dxc * dyl - dyc * dxl;
-
-  if (cross !== 0) return false;
-  else if (Math.abs(dxl) >= Math.abs(dyl))
-    return dxl > 0 ? startX <= x && x <= endX : endX <= x && x <= startX;
-  else return dyl > 0 ? startY <= y && y <= endY : endY <= y && y <= startY;
-}
-
 export { cleanCoords };
 export default cleanCoords;
diff --git a/packages/turf-clean-coords/package.json b/packages/turf-clean-coords/package.json
index 718bee991a..c4e3bb19d0 100644
--- a/packages/turf-clean-coords/package.json
+++ b/packages/turf-clean-coords/package.json
@@ -67,6 +67,7 @@
     "write-json-file": "^5.0.0"
   },
   "dependencies": {
+    "@turf/boolean-point-on-line": "workspace:^",
     "@turf/helpers": "workspace:^",
     "@turf/invariant": "workspace:^",
     "@types/geojson": "^7946.0.10",
diff --git a/packages/turf-clean-coords/test.ts b/packages/turf-clean-coords/test.ts
index 60f77f4cfd..4748281aec 100644
--- a/packages/turf-clean-coords/test.ts
+++ b/packages/turf-clean-coords/test.ts
@@ -151,3 +151,100 @@ test("turf-clean-coords -- prevent input mutation", (t) => {
   t.deepEqual(multiPolyBefore, multiPoly, "multiPolygon should NOT be mutated");
   t.end();
 });
+
+test("turf-clean-coords -- issue 2305", (t) => {
+  // From https://github.com/Turfjs/turf/issues/2305#issue-1287442870
+  t.deepEqual(
+    cleanCoords(
+      lineString([
+        [0, 0],
+        [0, 1],
+        [0, 0],
+      ])
+    ),
+    lineString([
+      [0, 0],
+      [0, 1],
+      [0, 0],
+    ])
+  );
+
+  // From https://github.com/Turfjs/turf/issues/2305#issue-1287442870
+  t.deepEqual(
+    cleanCoords(
+      lineString([
+        [0, 0],
+        [0, 0],
+        [0, 2],
+        [0, 2],
+        [0, 0],
+      ])
+    ),
+    lineString([
+      [0, 0],
+      [0, 2],
+      [0, 0],
+    ])
+  );
+
+  t.end();
+});
+
+test("turf-clean-coords -- issue 2740", (t) => {
+  // Issue 2740 is cleanCoords was too aggresive at removing points.
+  t.deepEqual(
+    cleanCoords(
+      lineString([
+        [0, 0],
+        [0, 2],
+        [0, 0],
+      ])
+    ),
+    lineString([
+      [0, 0],
+      [0, 2],
+      [0, 0],
+    ]),
+    "#2740 north-south retraced line"
+  );
+
+  t.deepEqual(
+    cleanCoords(
+      lineString([
+        [0, 0],
+        [0, 1],
+        [0, 2],
+        [0, 3],
+        [0, 0],
+      ])
+    ),
+    lineString([
+      [0, 0],
+      [0, 3],
+      [0, 0],
+    ]),
+    "#2740 north-south retraced line extra points"
+  );
+
+  t.deepEqual(
+    cleanCoords(
+      lineString([
+        [0, 0],
+        [0, 1],
+        [0, 2],
+        [0, -2],
+        [0, -1],
+        [0, 0],
+      ])
+    ),
+    lineString([
+      [0, 0],
+      [0, 2],
+      [0, -2],
+      [0, 0],
+    ]),
+    "#2740 north-south retraced past origin and back to start"
+  );
+
+  t.end();
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3ab4e90963..4448c6004b 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2057,6 +2057,9 @@ importers:
 
   packages/turf-clean-coords:
     dependencies:
+      '@turf/boolean-point-on-line':
+        specifier: workspace:^
+        version: link:../turf-boolean-point-on-line
       '@turf/helpers':
         specifier: workspace:^
         version: link:../turf-helpers

From 9f4eae629ef5a30533757d743dea6a490cef9414 Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Wed, 20 Nov 2024 15:39:55 +1100
Subject: [PATCH 2/5] Updated cleanCoords to run twice on polygons in case the
 start point was one of the points that should be cleaned.

---
 packages/turf-clean-coords/index.ts     | 34 ++++++++++++++++++++--
 packages/turf-clean-coords/package.json |  1 +
 packages/turf-clean-coords/test.ts      | 38 ++++++++++++++++++++++++-
 pnpm-lock.yaml                          |  3 ++
 4 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/packages/turf-clean-coords/index.ts b/packages/turf-clean-coords/index.ts
index 972abe70eb..5d09349359 100644
--- a/packages/turf-clean-coords/index.ts
+++ b/packages/turf-clean-coords/index.ts
@@ -45,14 +45,24 @@ function cleanCoords(
     case "MultiLineString":
     case "Polygon":
       getCoords(geojson).forEach(function (line) {
-        newCoords.push(cleanLine(line, type));
+        // Run cleanLine twice in case polygon start point is one of the points
+        // that ought to get cleaned.
+        // https://github.com/Turfjs/turf/issues/2406
+        const firstPass = cleanLine(line, type);
+        const secondPass = cleanLine(rotatePoints(firstPass), type);
+        newCoords.push(secondPass);
       });
       break;
     case "MultiPolygon":
       getCoords(geojson).forEach(function (polygons: any) {
         var polyPoints: Position[] = [];
         polygons.forEach(function (ring: Position[]) {
-          polyPoints.push(cleanLine(ring, type));
+          // Run cleanLine twice in case polygon start point is one of the points
+          // that ought to get cleaned.
+          // https://github.com/Turfjs/turf/issues/2406
+          const firstPass = cleanLine(ring, type);
+          const secondPass = cleanLine(rotatePoints(firstPass), type);
+          polyPoints.push(secondPass);
         });
         newCoords.push(polyPoints);
       });
@@ -164,5 +174,25 @@ function equals(pt1: Position, pt2: Position) {
   return pt1[0] === pt2[0] && pt1[1] === pt2[1];
 }
 
+/**
+ * Rotates a set of points to alter the start point of the polygon.
+ *
+ * @private
+ * @param {Position[]} pts Points to rotate
+ * @returns {Position[]} Rotated points
+ */
+function rotatePoints(pts: Position[]) {
+  // Don't alter the input pts array. Avoid side effects.
+  const points = pts.slice();
+  if (!equals(points[0], points[points.length - 1])) {
+    // Not a closed polygon so don't touch it.
+    return points;
+  }
+  points.pop(); // Discard duplicate closing point temporarily.
+  points.push(points.shift() as Position); // Shuffle points along a place.
+  points.push(points[0]); // Duplicate the new closing point to end of array.
+  return points;
+}
+
 export { cleanCoords };
 export default cleanCoords;
diff --git a/packages/turf-clean-coords/package.json b/packages/turf-clean-coords/package.json
index c4e3bb19d0..759e2716a9 100644
--- a/packages/turf-clean-coords/package.json
+++ b/packages/turf-clean-coords/package.json
@@ -54,6 +54,7 @@
     "test:types": "tsc --esModuleInterop --module node16 --moduleResolution node16 --noEmit --strict types.ts"
   },
   "devDependencies": {
+    "@turf/boolean-equal": "workspace:^",
     "@turf/truncate": "workspace:^",
     "@types/benchmark": "^2.1.5",
     "@types/tape": "^4.13.4",
diff --git a/packages/turf-clean-coords/test.ts b/packages/turf-clean-coords/test.ts
index 4748281aec..899436b0e6 100644
--- a/packages/turf-clean-coords/test.ts
+++ b/packages/turf-clean-coords/test.ts
@@ -4,6 +4,7 @@ import path from "path";
 import { fileURLToPath } from "url";
 import { loadJsonFileSync } from "load-json-file";
 import { truncate } from "@turf/truncate";
+import { booleanEqual } from "@turf/boolean-equal";
 import {
   point,
   multiPoint,
@@ -38,7 +39,10 @@ test("turf-clean-coords", (t) => {
 
     if (process.env.REGEN)
       writeJsonFileSync(directories.out + filename, results);
-    t.deepEqual(results, loadJsonFileSync(directories.out + filename), name);
+    t.true(
+      booleanEqual(results, loadJsonFileSync(directories.out + filename)),
+      name
+    );
   });
   t.end();
 });
@@ -248,3 +252,35 @@ test("turf-clean-coords -- issue 2740", (t) => {
 
   t.end();
 });
+
+test("turf-clean-coords -- issue 2406", (t) => {
+  t.true(
+    booleanEqual(
+      cleanCoords(
+        polygon([
+          [
+            [1, 3], // a
+            [3, 3], // b
+            [3, 1], // c
+            [3, -3], // d
+            [-3, -3], // e
+            [-3, 3], // f
+            [1, 3], // a
+          ],
+        ])
+      ),
+      polygon([
+        [
+          [-3, 3], // f
+          [3, 3], // b
+          [3, -3], // d
+          [-3, -3], // e
+          [-3, 3], // f
+        ],
+      ])
+    ),
+    "#2406 polygon start point (a) should also be removed"
+  );
+
+  t.end();
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 4448c6004b..e92dab0aea 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2073,6 +2073,9 @@ importers:
         specifier: ^2.8.1
         version: 2.8.1
     devDependencies:
+      '@turf/boolean-equal':
+        specifier: workspace:^
+        version: link:../turf-boolean-equal
       '@turf/truncate':
         specifier: workspace:^
         version: link:../turf-truncate

From e95daa9115d1d4ab1eb847de28636a10164daafc Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Wed, 20 Nov 2024 22:42:46 +1100
Subject: [PATCH 3/5] Less wasteful way to check if start / end point should be
 removed as part of clean operation.

---
 packages/turf-clean-coords/index.ts | 55 +++++++++++------------------
 1 file changed, 21 insertions(+), 34 deletions(-)

diff --git a/packages/turf-clean-coords/index.ts b/packages/turf-clean-coords/index.ts
index 5d09349359..8e02add71b 100644
--- a/packages/turf-clean-coords/index.ts
+++ b/packages/turf-clean-coords/index.ts
@@ -45,24 +45,14 @@ function cleanCoords(
     case "MultiLineString":
     case "Polygon":
       getCoords(geojson).forEach(function (line) {
-        // Run cleanLine twice in case polygon start point is one of the points
-        // that ought to get cleaned.
-        // https://github.com/Turfjs/turf/issues/2406
-        const firstPass = cleanLine(line, type);
-        const secondPass = cleanLine(rotatePoints(firstPass), type);
-        newCoords.push(secondPass);
+        newCoords.push(cleanLine(line, type));
       });
       break;
     case "MultiPolygon":
       getCoords(geojson).forEach(function (polygons: any) {
         var polyPoints: Position[] = [];
         polygons.forEach(function (ring: Position[]) {
-          // Run cleanLine twice in case polygon start point is one of the points
-          // that ought to get cleaned.
-          // https://github.com/Turfjs/turf/issues/2406
-          const firstPass = cleanLine(ring, type);
-          const secondPass = cleanLine(rotatePoints(firstPass), type);
-          polyPoints.push(secondPass);
+          polyPoints.push(cleanLine(ring, type));
         });
         newCoords.push(polyPoints);
       });
@@ -149,9 +139,26 @@ function cleanLine(line: Position[], type: string) {
   // No remaining points, so commit the current a-b segment.
   newPoints.push(points[b]);
 
-  // (Multi)Polygons must have at least 4 points and be closed.
   if (type === "Polygon" || type === "MultiPolygon") {
-    if (!equals(points[0], points[points.length - 1])) {
+    // For polygons need to make sure the start / end point wasn't one of the
+    // points that needed to be cleaned.
+    // https://github.com/Turfjs/turf/issues/2406
+    // For points [a, b, c, ..., z, a]
+    // if a is on line b-z, it too can be removed. New array becomes
+    // [b, c, ..., z, b]
+    if (
+      booleanPointOnLine(
+        newPoints[0],
+        lineString([newPoints[1], points[newPoints.length - 2]])
+      )
+    ) {
+      newPoints.shift(); // Discard starting point.
+      newPoints.pop(); // Discard closing point.
+      newPoints.push(newPoints[0]); // Duplicate the new closing point to end of array.
+    }
+
+    // (Multi)Polygons must have at least 4 points and be closed.
+    if (!equals(newPoints[0], newPoints[newPoints.length - 1])) {
       throw new Error("invalid polygon, first and last points not equal");
     }
     if (newPoints.length < 4) {
@@ -174,25 +181,5 @@ function equals(pt1: Position, pt2: Position) {
   return pt1[0] === pt2[0] && pt1[1] === pt2[1];
 }
 
-/**
- * Rotates a set of points to alter the start point of the polygon.
- *
- * @private
- * @param {Position[]} pts Points to rotate
- * @returns {Position[]} Rotated points
- */
-function rotatePoints(pts: Position[]) {
-  // Don't alter the input pts array. Avoid side effects.
-  const points = pts.slice();
-  if (!equals(points[0], points[points.length - 1])) {
-    // Not a closed polygon so don't touch it.
-    return points;
-  }
-  points.pop(); // Discard duplicate closing point temporarily.
-  points.push(points.shift() as Position); // Shuffle points along a place.
-  points.push(points[0]); // Duplicate the new closing point to end of array.
-  return points;
-}
-
 export { cleanCoords };
 export default cleanCoords;

From c454a03fcc10f40905a8e1bbab3f1c4596e0280d Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Tue, 17 Dec 2024 07:22:58 +1100
Subject: [PATCH 4/5] Made unit test messages more descriptive and added to
 contributors.

---
 packages/turf-clean-coords/package.json |  3 ++-
 packages/turf-clean-coords/test.ts      | 20 +++++++++++---------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/packages/turf-clean-coords/package.json b/packages/turf-clean-coords/package.json
index 759e2716a9..3af6e79fb0 100644
--- a/packages/turf-clean-coords/package.json
+++ b/packages/turf-clean-coords/package.json
@@ -4,7 +4,8 @@
   "description": "turf clean-coords module",
   "author": "Turf Authors",
   "contributors": [
-    "Stefano Borghi <@stebogit>"
+    "Stefano Borghi <@stebogit>",
+    "James Beard <@smallsaucepan>"
   ],
   "license": "MIT",
   "bugs": {
diff --git a/packages/turf-clean-coords/test.ts b/packages/turf-clean-coords/test.ts
index 899436b0e6..8244d62c28 100644
--- a/packages/turf-clean-coords/test.ts
+++ b/packages/turf-clean-coords/test.ts
@@ -156,7 +156,7 @@ test("turf-clean-coords -- prevent input mutation", (t) => {
   t.end();
 });
 
-test("turf-clean-coords -- issue 2305", (t) => {
+test("turf-clean-coords - north south lines - issue 2305", (t) => {
   // From https://github.com/Turfjs/turf/issues/2305#issue-1287442870
   t.deepEqual(
     cleanCoords(
@@ -170,7 +170,8 @@ test("turf-clean-coords -- issue 2305", (t) => {
       [0, 0],
       [0, 1],
       [0, 0],
-    ])
+    ]),
+    "northern turnaround point is kept"
   );
 
   // From https://github.com/Turfjs/turf/issues/2305#issue-1287442870
@@ -188,13 +189,14 @@ test("turf-clean-coords -- issue 2305", (t) => {
       [0, 0],
       [0, 2],
       [0, 0],
-    ])
+    ]),
+    "northern turnaround point is kept"
   );
 
   t.end();
 });
 
-test("turf-clean-coords -- issue 2740", (t) => {
+test("turf-clean-coords - overly aggressive removal - issue 2740", (t) => {
   // Issue 2740 is cleanCoords was too aggresive at removing points.
   t.deepEqual(
     cleanCoords(
@@ -209,7 +211,7 @@ test("turf-clean-coords -- issue 2740", (t) => {
       [0, 2],
       [0, 0],
     ]),
-    "#2740 north-south retraced line"
+    "north-south retraced line turnaround point kept"
   );
 
   t.deepEqual(
@@ -227,7 +229,7 @@ test("turf-clean-coords -- issue 2740", (t) => {
       [0, 3],
       [0, 0],
     ]),
-    "#2740 north-south retraced line extra points"
+    "north-south retraced line properly cleaned"
   );
 
   t.deepEqual(
@@ -247,13 +249,13 @@ test("turf-clean-coords -- issue 2740", (t) => {
       [0, -2],
       [0, 0],
     ]),
-    "#2740 north-south retraced past origin and back to start"
+    "north-south retraced past origin and back to start line properly cleaned"
   );
 
   t.end();
 });
 
-test("turf-clean-coords -- issue 2406", (t) => {
+test("turf-clean-coords - start point protected - issue 2406", (t) => {
   t.true(
     booleanEqual(
       cleanCoords(
@@ -279,7 +281,7 @@ test("turf-clean-coords -- issue 2406", (t) => {
         ],
       ])
     ),
-    "#2406 polygon start point (a) should also be removed"
+    "polygon start point (a) was also removed"
   );
 
   t.end();

From 3ed5b230649738fc70606f11f2ca2d930b21aa7d Mon Sep 17 00:00:00 2001
From: James Beard <james@smallsaucepan.com>
Date: Sat, 21 Dec 2024 18:13:02 +1100
Subject: [PATCH 5/5] Fixed issue where a polygon that got cleaned down to a
 single line segment was causing errors - started checking number of points
 before doing other tests. Replaced our own booleanEquals with external
 geojsonEquality. booleanEquals uses cleanCoords, which we're using to check
 ... cleanCoords. Fixed a couple of linting issues.

---
 packages/turf-boolean-disjoint/index.ts |  1 -
 packages/turf-clean-coords/index.ts     |  8 +--
 packages/turf-clean-coords/package.json |  2 +-
 packages/turf-clean-coords/test.ts      | 38 ++++++++++++-
 packages/turf-meta/test.ts              |  2 +-
 pnpm-lock.yaml                          | 74 +++++++++++++++++++++++--
 6 files changed, 110 insertions(+), 15 deletions(-)

diff --git a/packages/turf-boolean-disjoint/index.ts b/packages/turf-boolean-disjoint/index.ts
index 60e89c23ff..4bcc07c426 100644
--- a/packages/turf-boolean-disjoint/index.ts
+++ b/packages/turf-boolean-disjoint/index.ts
@@ -65,7 +65,6 @@ function booleanDisjoint(
 function disjoint(geom1: any, geom2: any, ignoreSelfIntersections: boolean) {
   switch (geom1.type) {
     case "Point":
-      /* eslint-disable @typescript-eslint/no-unused-vars */
       switch (geom2.type) {
         case "Point":
           return !compareCoords(geom1.coordinates, geom2.coordinates);
diff --git a/packages/turf-clean-coords/index.ts b/packages/turf-clean-coords/index.ts
index 8e02add71b..9c8660252c 100644
--- a/packages/turf-clean-coords/index.ts
+++ b/packages/turf-clean-coords/index.ts
@@ -149,7 +149,7 @@ function cleanLine(line: Position[], type: string) {
     if (
       booleanPointOnLine(
         newPoints[0],
-        lineString([newPoints[1], points[newPoints.length - 2]])
+        lineString([newPoints[1], newPoints[newPoints.length - 2]])
       )
     ) {
       newPoints.shift(); // Discard starting point.
@@ -158,12 +158,12 @@ function cleanLine(line: Position[], type: string) {
     }
 
     // (Multi)Polygons must have at least 4 points and be closed.
-    if (!equals(newPoints[0], newPoints[newPoints.length - 1])) {
-      throw new Error("invalid polygon, first and last points not equal");
-    }
     if (newPoints.length < 4) {
       throw new Error("invalid polygon, fewer than 4 points");
     }
+    if (!equals(newPoints[0], newPoints[newPoints.length - 1])) {
+      throw new Error("invalid polygon, first and last points not equal");
+    }
   }
 
   return newPoints;
diff --git a/packages/turf-clean-coords/package.json b/packages/turf-clean-coords/package.json
index 3af6e79fb0..72f767e74b 100644
--- a/packages/turf-clean-coords/package.json
+++ b/packages/turf-clean-coords/package.json
@@ -55,11 +55,11 @@
     "test:types": "tsc --esModuleInterop --module node16 --moduleResolution node16 --noEmit --strict types.ts"
   },
   "devDependencies": {
-    "@turf/boolean-equal": "workspace:^",
     "@turf/truncate": "workspace:^",
     "@types/benchmark": "^2.1.5",
     "@types/tape": "^4.13.4",
     "benchmark": "^2.1.4",
+    "geojson-equality-ts": "^1.0.2",
     "load-json-file": "^7.0.1",
     "npm-run-all": "^4.1.5",
     "tape": "^5.9.0",
diff --git a/packages/turf-clean-coords/test.ts b/packages/turf-clean-coords/test.ts
index 8244d62c28..8bd99215f9 100644
--- a/packages/turf-clean-coords/test.ts
+++ b/packages/turf-clean-coords/test.ts
@@ -1,10 +1,10 @@
 import fs from "fs";
 import test from "tape";
 import path from "path";
+import { geojsonEquality } from "geojson-equality-ts";
 import { fileURLToPath } from "url";
 import { loadJsonFileSync } from "load-json-file";
 import { truncate } from "@turf/truncate";
-import { booleanEqual } from "@turf/boolean-equal";
 import {
   point,
   multiPoint,
@@ -40,7 +40,7 @@ test("turf-clean-coords", (t) => {
     if (process.env.REGEN)
       writeJsonFileSync(directories.out + filename, results);
     t.true(
-      booleanEqual(results, loadJsonFileSync(directories.out + filename)),
+      geojsonEquality(results, loadJsonFileSync(directories.out + filename)),
       name
     );
   });
@@ -257,7 +257,7 @@ test("turf-clean-coords - overly aggressive removal - issue 2740", (t) => {
 
 test("turf-clean-coords - start point protected - issue 2406", (t) => {
   t.true(
-    booleanEqual(
+    geojsonEquality(
       cleanCoords(
         polygon([
           [
@@ -286,3 +286,35 @@ test("turf-clean-coords - start point protected - issue 2406", (t) => {
 
   t.end();
 });
+
+test("turf-clean-coords - multipolygon - issue #918", (t) => {
+  // Copied from turf-simplify as (at heart) it's cleanCoords that's being
+  // tested here.
+  // simplify hangs on this input #918
+  t.throws(
+    () =>
+      cleanCoords(
+        multiPolygon([
+          [
+            [
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+              [0, 90],
+            ],
+          ],
+        ])
+      ),
+    /invalid polygon/,
+    "invalid polygon"
+  );
+
+  t.end();
+});
diff --git a/packages/turf-meta/test.ts b/packages/turf-meta/test.ts
index a8589fe0e3..8c59c0e0bd 100644
--- a/packages/turf-meta/test.ts
+++ b/packages/turf-meta/test.ts
@@ -532,7 +532,7 @@ test("null geometries", (t) => {
     0,
     "coordReduce"
   );
-  /* eslint-enable no-return-assign */
+
   t.end();
 });
 
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index e92dab0aea..ca8de70d22 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2073,9 +2073,6 @@ importers:
         specifier: ^2.8.1
         version: 2.8.1
     devDependencies:
-      '@turf/boolean-equal':
-        specifier: workspace:^
-        version: link:../turf-boolean-equal
       '@turf/truncate':
         specifier: workspace:^
         version: link:../turf-truncate
@@ -2088,6 +2085,9 @@ importers:
       benchmark:
         specifier: ^2.1.4
         version: 2.1.4
+      geojson-equality-ts:
+        specifier: ^1.0.2
+        version: 1.0.2
       load-json-file:
         specifier: ^7.0.1
         version: 7.0.1
@@ -2099,7 +2099,7 @@ importers:
         version: 5.9.0
       tsup:
         specifier: ^8.3.5
-        version: 8.3.5(postcss@8.4.40)(tsx@4.19.2)(typescript@5.5.4)
+        version: 8.3.5(tsx@4.19.2)(typescript@5.5.4)
       tsx:
         specifier: ^4.19.2
         version: 4.19.2
@@ -12103,7 +12103,6 @@ packages:
     resolution: {integrity: sha512-h3Ryq+0mCSN/7yLs0eDgrZhvc9af23o/QuC4aTiuuzP/MRCtd6mf5rLsLRY44jX0RPUfM8c4GqERQmlUxPGPoQ==}
     dependencies:
       '@types/geojson': 7946.0.14
-    dev: false
 
   /geojson-polygon-self-intersections@1.2.1:
     resolution: {integrity: sha512-/QM1b5u2d172qQVO//9CGRa49jEmclKEsYOQmWP9ooEjj63tBM51m2805xsbxkzlEELQ2REgTf700gUhhlegxA==}
@@ -15416,6 +15415,28 @@ packages:
       tsx: 4.19.2
     dev: true
 
+  /postcss-load-config@6.0.1(tsx@4.19.2):
+    resolution: {integrity: sha512-oPtTM4oerL+UXmx+93ytZVN82RrlY/wPUV8IeDxFrzIjXOLF1pN+EmKPLbubvKHT2HC20xXsCAH2Z+CKV6Oz/g==}
+    engines: {node: '>= 18'}
+    peerDependencies:
+      jiti: '>=1.21.0'
+      postcss: '>=8.0.9'
+      tsx: ^4.8.1
+      yaml: ^2.4.2
+    peerDependenciesMeta:
+      jiti:
+        optional: true
+      postcss:
+        optional: true
+      tsx:
+        optional: true
+      yaml:
+        optional: true
+    dependencies:
+      lilconfig: 3.1.3
+      tsx: 4.19.2
+    dev: true
+
   /postcss-selector-parser@6.1.2:
     resolution: {integrity: sha512-Q8qQfPiZ+THO/3ZrOrO0cJJKfpYCagtMUkXbnEfmgUjwXg6z/WBeOyS9APBBPCTSiDV+s4SwQGu8yFsiMRIudg==}
     engines: {node: '>=4'}
@@ -17030,6 +17051,49 @@ packages:
       - yaml
     dev: true
 
+  /tsup@8.3.5(tsx@4.19.2)(typescript@5.5.4):
+    resolution: {integrity: sha512-Tunf6r6m6tnZsG9GYWndg0z8dEV7fD733VBFzFJ5Vcm1FtlXB8xBD/rtrBi2a3YKEV7hHtxiZtW5EAVADoe1pA==}
+    engines: {node: '>=18'}
+    hasBin: true
+    peerDependencies:
+      '@microsoft/api-extractor': ^7.36.0
+      '@swc/core': ^1
+      postcss: ^8.4.12
+      typescript: '>=4.5.0'
+    peerDependenciesMeta:
+      '@microsoft/api-extractor':
+        optional: true
+      '@swc/core':
+        optional: true
+      postcss:
+        optional: true
+      typescript:
+        optional: true
+    dependencies:
+      bundle-require: 5.0.0(esbuild@0.24.0)
+      cac: 6.7.14
+      chokidar: 4.0.1
+      consola: 3.2.3
+      debug: 4.3.7
+      esbuild: 0.24.0
+      joycon: 3.1.1
+      picocolors: 1.1.1
+      postcss-load-config: 6.0.1(tsx@4.19.2)
+      resolve-from: 5.0.0
+      rollup: 4.28.0
+      source-map: 0.8.0-beta.0
+      sucrase: 3.35.0
+      tinyexec: 0.3.1
+      tinyglobby: 0.2.10
+      tree-kill: 1.2.2
+      typescript: 5.5.4
+    transitivePeerDependencies:
+      - jiti
+      - supports-color
+      - tsx
+      - yaml
+    dev: true
+
   /tsx@4.19.2:
     resolution: {integrity: sha512-pOUl6Vo2LUq/bSa8S5q7b91cgNSjctn9ugq/+Mvow99qW6x/UZYwzxy/3NmqoT66eHYfCVvFvACC58UBPFf28g==}
     engines: {node: '>=18.0.0'}