fix(association): a figure counted as none comes off the band

services/frontend/src/domains/association/island/NumberBand.vue

@@ -2,12 +2,13 @@
 import {figureText, type Figure} from "../numbers"
 
 /**
- * The association in four numbers, across the page.
+ * The association in a handful of numbers, across the page.
  *
  * Every figure is drawn the moment the band is: the ones the api counts start on the floors the
- * association publishes about itself and are replaced where the counts land, so the band never
- * changes height and there is nothing pulsing on the page that is meant to sell membership. A
- * figure that is a floor rather than a count says so with a `+`.
+ * association publishes about itself and are replaced where the counts land, so there is
+ * nothing pulsing on the page that is meant to sell membership. A figure that is a floor rather
+ * than a count says so with a `+`. Usually four; a figure the api counted as none is not on the
+ * band at all, so the band draws what it is given rather than a fixed set.
  */
 defineOptions({name: "NumberBand"})
 

services/frontend/src/domains/association/numbers.ts

@@ -84,9 +84,16 @@ const counted = (
   label: string,
 ): Figure => ({id, value: value ?? floor, exact: numbers != null, label})
 
-/** The figures a page names, in the order it names them. */
+/**
+ * The figures a page names, in the order it names them, less any the api counted as none.
+ *
+ * A page that sells the association does not print `0 Events in the past year`. Nor does it
+ * fall back to the published floor there: the floor stands for a number nobody has counted yet,
+ * and a counted zero has been counted. The figure comes off the band, and the ones either side
+ * of it close up.
+ */
 export function figuresFor(ids: readonly FigureId[], numbers: AssociationNumbers | null): Figure[] {
-  return ids.map(id => FIGURES[id](numbers))
+  return ids.map(id => FIGURES[id](numbers)).filter(figure => !(figure.exact && figure.value === 0))
 }
 
 /** What the membership page leads with. */

services/frontend/tests/unit/domains/association/numbers.test.ts

@@ -1,6 +1,7 @@
 import {describe, expect, it} from "vitest"
 import {
   associationFigures,
+  figuresFor,
   figureText,
   FLOORS,
   MEMBERS_CLAIMED,
@@ -45,6 +46,24 @@ describe("associationFigures", () => {
 })
 
 describe("figureText", () => {
+  /**
+   * A page that sells the association does not print `0 Events in the past year`.
+   *
+   * Nor does it fall back to the published floor there: the floor stands for a number nobody
+   * has counted yet, and a counted zero has been counted.
+   */
+  it("leaves out a figure the api counted as none", () => {
+    const none = figuresFor(["members", "teams", "events"], {...counted, eventsLastYear: 0})
+
+    expect(none.map(figure => figure.id)).toEqual(["members", "teams"])
+  })
+
+  it("keeps a figure nobody has counted yet, on its floor", () => {
+    const unread = figuresFor(["events"], null)
+
+    expect(unread).toMatchObject([{id: "events", value: FLOORS.eventsLastYear, exact: false}])
+  })
+
   it("marks a floor as at least that many and states a count plainly", () => {
     expect(figureText({id: "members", value: 200, exact: false, label: ""})).toBe("200+")
     expect(figureText({id: "teams", value: 13, exact: true, label: ""})).toBe("13")