lax className (#2126)

src/mark.js

@@ -2,9 +2,9 @@ import {channelDomain, createChannels, valueObject} from "./channel.js";
 import {defined} from "./defined.js";
 import {maybeFacetAnchor} from "./facet.js";
 import {maybeClip, maybeNamed, maybeValue} from "./options.js";
-import {dataify, isDomainSort, isObject, isOptions, keyword, range, singleton} from "./options.js";
+import {dataify, isDomainSort, isObject, isOptions, keyword, range, singleton, string} from "./options.js";
 import {project} from "./projection.js";
-import {maybeClassName, styles} from "./style.js";
+import {styles} from "./style.js";
 import {basic, initializer} from "./transforms/basic.js";
 
 export class Mark {
@@ -72,7 +72,7 @@ export class Mark {
     this.marginLeft = +marginLeft;
     this.clip = maybeClip(clip);
     this.tip = maybeTip(tip);
-    this.className = className ? maybeClassName(className) : null;
+    this.className = string(className);
     // Super-faceting currently disallow position channels; in the future, we
     // could allow position to be specified in fx and fy in addition to (or
     // instead of) x and y.

test/plots/class-name.ts

@@ -12,7 +12,7 @@ export async function classNameOnMarks() {
     marks: [
       Plot.barX(
         sales,
-        Plot.groupY({x: "sum"}, {x: "units", y: "fruit", sort: {y: "x", reverse: true}, className: "fruitbars"})
+        Plot.groupY({x: "sum"}, {x: "units", y: "fruit", sort: {y: "x", reverse: true}, className: "fruit units"})
       ),
       Plot.ruleX([0])
     ]