Index: node_modules/d3-shape/src/curve/cardinalOpen.js
===================================================================
--- node_modules/d3-shape/src/curve/cardinalOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/cardinalOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,49 @@
+import {point} from "./cardinal.js";
+
+export function CardinalOpen(context, tension) {
+  this._context = context;
+  this._k = (1 - tension) / 6;
+}
+
+CardinalOpen.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x0 = this._x1 = this._x2 =
+    this._y0 = this._y1 = this._y2 = NaN;
+    this._point = 0;
+  },
+  lineEnd: function() {
+    if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
+    this._line = 1 - this._line;
+  },
+  point: function(x, y) {
+    x = +x, y = +y;
+    switch (this._point) {
+      case 0: this._point = 1; break;
+      case 1: this._point = 2; break;
+      case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
+      case 3: this._point = 4; // falls through
+      default: point(this, x, y); break;
+    }
+    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
+    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
+  }
+};
+
+export default (function custom(tension) {
+
+  function cardinal(context) {
+    return new CardinalOpen(context, tension);
+  }
+
+  cardinal.tension = function(tension) {
+    return custom(+tension);
+  };
+
+  return cardinal;
+})(0);