Index: node_modules/d3-geo/src/path/measure.js
===================================================================
--- node_modules/d3-geo/src/path/measure.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-geo/src/path/measure.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,45 @@
+import {Adder} from "d3-array";
+import {sqrt} from "../math.js";
+import noop from "../noop.js";
+
+var lengthSum = new Adder(),
+    lengthRing,
+    x00,
+    y00,
+    x0,
+    y0;
+
+var lengthStream = {
+  point: noop,
+  lineStart: function() {
+    lengthStream.point = lengthPointFirst;
+  },
+  lineEnd: function() {
+    if (lengthRing) lengthPoint(x00, y00);
+    lengthStream.point = noop;
+  },
+  polygonStart: function() {
+    lengthRing = true;
+  },
+  polygonEnd: function() {
+    lengthRing = null;
+  },
+  result: function() {
+    var length = +lengthSum;
+    lengthSum = new Adder();
+    return length;
+  }
+};
+
+function lengthPointFirst(x, y) {
+  lengthStream.point = lengthPoint;
+  x00 = x0 = x, y00 = y0 = y;
+}
+
+function lengthPoint(x, y) {
+  x0 -= x, y0 -= y;
+  lengthSum.add(sqrt(x0 * x0 + y0 * y0));
+  x0 = x, y0 = y;
+}
+
+export default lengthStream;