Index: node_modules/d3-transition/src/transition/interpolate.js
===================================================================
--- node_modules/d3-transition/src/transition/interpolate.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-transition/src/transition/interpolate.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,10 @@
+import {color} from "d3-color";
+import {interpolateNumber, interpolateRgb, interpolateString} from "d3-interpolate";
+
+export default function(a, b) {
+  var c;
+  return (typeof b === "number" ? interpolateNumber
+      : b instanceof color ? interpolateRgb
+      : (c = color(b)) ? (b = c, interpolateRgb)
+      : interpolateString)(a, b);
+}