Index: node_modules/d3-shape/src/line.js
===================================================================
--- node_modules/d3-shape/src/line.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/line.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,58 @@
+import array from "./array.js";
+import constant from "./constant.js";
+import curveLinear from "./curve/linear.js";
+import {withPath} from "./path.js";
+import {x as pointX, y as pointY} from "./point.js";
+
+export default function(x, y) {
+  var defined = constant(true),
+      context = null,
+      curve = curveLinear,
+      output = null,
+      path = withPath(line);
+
+  x = typeof x === "function" ? x : (x === undefined) ? pointX : constant(x);
+  y = typeof y === "function" ? y : (y === undefined) ? pointY : constant(y);
+
+  function line(data) {
+    var i,
+        n = (data = array(data)).length,
+        d,
+        defined0 = false,
+        buffer;
+
+    if (context == null) output = curve(buffer = path());
+
+    for (i = 0; i <= n; ++i) {
+      if (!(i < n && defined(d = data[i], i, data)) === defined0) {
+        if (defined0 = !defined0) output.lineStart();
+        else output.lineEnd();
+      }
+      if (defined0) output.point(+x(d, i, data), +y(d, i, data));
+    }
+
+    if (buffer) return output = null, buffer + "" || null;
+  }
+
+  line.x = function(_) {
+    return arguments.length ? (x = typeof _ === "function" ? _ : constant(+_), line) : x;
+  };
+
+  line.y = function(_) {
+    return arguments.length ? (y = typeof _ === "function" ? _ : constant(+_), line) : y;
+  };
+
+  line.defined = function(_) {
+    return arguments.length ? (defined = typeof _ === "function" ? _ : constant(!!_), line) : defined;
+  };
+
+  line.curve = function(_) {
+    return arguments.length ? (curve = _, context != null && (output = curve(context)), line) : curve;
+  };
+
+  line.context = function(_) {
+    return arguments.length ? (_ == null ? context = output = null : output = curve(context = _), line) : context;
+  };
+
+  return line;
+}