fix tickFormat type inference for empty domain

Author: mbostock

src/marks/axis.js

@@ -672,10 +672,10 @@ export function inferTickFormat(scale, data, ticks, tickFormat, anchor) {
     ? inferTimeFormat(scale.type, data, anchor) ?? formatDefault
     : scale.tickFormat
     ? scale.tickFormat(typeof ticks === "number" ? ticks : null, tickFormat)
+    : typeof tickFormat === "string" && scale.domain().length > 0
+    ? (isTemporal(scale.domain()) ? utcFormat : format)(tickFormat)
     : tickFormat === undefined
     ? formatDefault
-    : typeof tickFormat === "string"
-    ? (isTemporal(scale.domain()) ? utcFormat : format)(tickFormat)
     : constant(tickFormat);
 }
 

test/output/tickFormatEmptyDomain.svg

@@ -308,6 +308,7 @@ export * from "./style-overrides.js";
 export * from "./symbol-set.js";
 export * from "./text-overflow.js";
 export * from "./this-is-just-to-say.js";
+export * from "./tick-format.js";
 export * from "./time-axis.js";
 export * from "./tip-format.js";
 export * from "./tip.js";

test/output/tickFormatEmptyFacetDomain.svg

@@ -0,0 +1,9 @@
+import * as Plot from "@observablehq/plot";
+
+export async function tickFormatEmptyDomain() {
+  return Plot.plot({y: {tickFormat: "%W"}, marks: [Plot.barX([]), Plot.frame()]});
+}
+
+export async function tickFormatEmptyFacetDomain() {
+  return Plot.plot({fy: {tickFormat: "%W"}, marks: [Plot.barX([]), Plot.frame()]});
+}