Index: node_modules/d3-shape/src/curve/basis.js
===================================================================
--- node_modules/d3-shape/src/curve/basis.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/basis.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,51 @@
+export function point(that, x, y) {
+  that._context.bezierCurveTo(
+    (2 * that._x0 + that._x1) / 3,
+    (2 * that._y0 + that._y1) / 3,
+    (that._x0 + 2 * that._x1) / 3,
+    (that._y0 + 2 * that._y1) / 3,
+    (that._x0 + 4 * that._x1 + x) / 6,
+    (that._y0 + 4 * that._y1 + y) / 6
+  );
+}
+
+export function Basis(context) {
+  this._context = context;
+}
+
+Basis.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x0 = this._x1 =
+    this._y0 = this._y1 = NaN;
+    this._point = 0;
+  },
+  lineEnd: function() {
+    switch (this._point) {
+      case 3: point(this, this._x1, this._y1); // falls through
+      case 2: this._context.lineTo(this._x1, this._y1); break;
+    }
+    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
+    this._line = 1 - this._line;
+  },
+  point: function(x, y) {
+    x = +x, y = +y;
+    switch (this._point) {
+      case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
+      case 1: this._point = 2; break;
+      case 2: this._point = 3; this._context.lineTo((5 * this._x0 + this._x1) / 6, (5 * this._y0 + this._y1) / 6); // falls through
+      default: point(this, x, y); break;
+    }
+    this._x0 = this._x1, this._x1 = x;
+    this._y0 = this._y1, this._y1 = y;
+  }
+};
+
+export default function(context) {
+  return new Basis(context);
+}