null-safe sort (#1348)

Author: mbostock

src/channel.js

@@ -1,4 +1,5 @@
-import {ascending, descending, InternSet, rollup, sort} from "d3";
+import {InternSet, rollup, sort} from "d3";
+import {ascendingDefined, descendingDefined} from "./defined.js";
 import {first, isColor, isEvery, isIterable, isOpacity, labelof, map, maybeValue, range, valueof} from "./options.js";
 import {registry} from "./scales/index.js";
 import {isSymbol, maybeSymbol} from "./symbol.js";
@@ -153,9 +154,9 @@ function values(channels, name, alias) {
 }
 
 function ascendingGroup([ak, av], [bk, bv]) {
-  return ascending(av, bv) || ascending(ak, bk);
+  return ascendingDefined(av, bv) || ascendingDefined(ak, bk);
 }
 
 function descendingGroup([ak, av], [bk, bv]) {
-  return descending(av, bv) || ascending(ak, bk);
+  return descendingDefined(av, bv) || ascendingDefined(ak, bk);
 }

test/output/athletesSortWeightLimit.svg

@@ -38,3 +38,14 @@ export async function athletesSortNullLimit() {
     marks: [Plot.dot(athletes, {x: "height", y: "weight", stroke: "nationality", sort: {color: null, limit: 10}})]
   });
 }
+
+export async function athletesSortWeightLimit() {
+  const athletes = await d3.csv<any>("data/athletes.csv", d3.autoType);
+  return Plot.plot({
+    color: {legend: true},
+    marks: [
+      Plot.dot(athletes, {x: "weight", y: "nationality", sort: {y: "x", reduce: "median", limit: 10}}),
+      Plot.tickX(athletes, Plot.groupY({x: "median"}, {x: "weight", y: "nationality", stroke: "red", strokeWidth: 2}))
+    ]
+  });
+}