src/components/budget/BudgetTable.render.test.tsx

@@ -0,0 +1,205 @@
+// BudgetTable and the getting-started card's target (#400). No jsdom:
+// react-dom/server renders in vitest's node environment. The collapse hook is
+// replaced by the real pure helpers over a state the test sets (the real hook
+// hydrates in an effect, which a static render never runs), and the
+// subtotal-position preference is read from a stubbed localStorage. What is
+// pinned is where the one highlight lands: "Expand all" or this month's cell
+// of the first editable row shown.
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+import type { BudgetYearRow } from "../../shared/types";
+import type { CollapseAccessors } from "../../utils/collapsibleRows";
+
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (k: string) => `t(${k})`, i18n: { language: "fr" } }),
+}));
+
+const harness = vi.hoisted(() => ({
+  /** Keys of the open groups (`p:<category id>`): the grid opens collapsed. */
+  expanded: new Set<string>(),
+}));
+
+vi.mock("../../hooks/useCollapsibleGroups", async () => {
+  const { collapsibleKeys, isCollapsedFor, visibleRows } = await import("../../utils/collapsibleRows");
+  return {
+    useCollapsibleGroups: <T,>(_key: string | null, acc: CollapseAccessors<T>) => {
+      const isCollapsed = (row: T) => isCollapsedFor(harness.expanded, acc.keyOf(row), false);
+      return {
+        visible: (rows: T[]) => visibleRows(rows, acc, isCollapsed),
+        isCollapsed,
+        toggle: () => undefined,
+        expandAll: () => undefined,
+        collapseAll: () => undefined,
+        allExpanded: (rows: T[]) => {
+          const keys = collapsibleKeys(rows, acc);
+          return keys.length > 0 && keys.every((key) => harness.expanded.has(key));
+        },
+        groupCount: (rows: T[]) => collapsibleKeys(rows, acc).length,
+      };
+    },
+  };
+});
+
+import BudgetTable, { BUDGET_CELL_TARGET, BUDGET_EXPAND_ALL_TARGET } from "./BudgetTable";
+
+const leaf = (
+  category_id: number,
+  category_name: string,
+  category_type: BudgetYearRow["category_type"],
+  parent_id: number | null = null,
+): BudgetYearRow => ({
+  category_id,
+  category_name,
+  category_color: "#9ca3af",
+  category_type,
+  parent_id,
+  is_parent: false,
+  depth: parent_id === null ? 0 : 1,
+  months: Array(12).fill(0) as number[],
+  annual: 0,
+  previousYearTotal: 0,
+});
+const group = (
+  category_id: number,
+  category_name: string,
+  category_type: BudgetYearRow["category_type"],
+): BudgetYearRow => ({ ...leaf(category_id, category_name, category_type), is_parent: true });
+
+/** Two groups, in the order `buildBudgetYearRows` emits them: income first. */
+const GROUPED: BudgetYearRow[] = [
+  group(1, "Revenus", "income"),
+  leaf(2, "Salaire", "income", 1),
+  group(10, "Logement", "expense"),
+  leaf(11, "Loyer", "expense", 10),
+  leaf(12, "Électricité", "expense", 10),
+];
+/** A category without sub-category stays on screen while the groups are collapsed. */
+const WITH_STANDALONE: BudgetYearRow[] = [...GROUPED, leaf(30, "Divers", "expense")];
+/** No group at all. */
+const FLAT: BudgetYearRow[] = [leaf(30, "Divers", "expense"), leaf(31, "Cadeaux", "expense")];
+
+const MARCH = 2;
+const DECEMBER = 11;
+
+const render = (rows: BudgetYearRow[], onboardingTarget?: boolean) =>
+  renderToStaticMarkup(
+    <BudgetTable
+      rows={rows}
+      onUpdatePlanned={() => undefined}
+      onSplitEvenly={() => undefined}
+      onboardingTarget={onboardingTarget}
+    />,
+  );
+
+const HIGHLIGHT = 'data-onboarding-highlight="true"';
+const count = (html: string, needle: string) => html.split(needle).length - 1;
+
+/** The one highlighted control: its target key and its inner markup. */
+function highlighted(html: string): { target: string; inner: string } {
+  expect(count(html, HIGHLIGHT)).toBe(1);
+  const match = html.match(/<button [^>]*data-onboarding-target="([^"]+)" data-onboarding-highlight="true"[^>]*>(.*?)<\/button>/);
+  expect(match).not.toBeNull();
+  return { target: match![1], inner: match![2] };
+}
+
+/** The markup of the row named `name`, from its `<tr` to its `</tr>`. */
+function rowOf(html: string, name: string): string {
+  const at = html.indexOf(`>${name}<`);
+  expect(at).toBeGreaterThan(-1);
+  return html.slice(html.lastIndexOf("<tr", at), html.indexOf("</tr>", at));
+}
+
+/** The month (0-11) of the highlighted cell in a row, -1 for none: name, last year and annual come first. */
+function ringedMonth(row: string): number {
+  const cell = row
+    .split("<td")
+    .slice(1)
+    .findIndex((td) => td.includes(HIGHLIGHT));
+  return cell === -1 ? -1 : cell - 3;
+}
+
+beforeEach(() => {
+  harness.expanded = new Set();
+  vi.stubGlobal("localStorage", { getItem: () => null, setItem: () => undefined });
+  vi.useFakeTimers({ toFake: ["Date"] });
+  vi.setSystemTime(new Date(2026, MARCH, 15));
+});
+
+afterEach(() => {
+  vi.useRealTimers();
+  vi.unstubAllGlobals();
+});
+
+describe("BudgetTable — the getting-started card's target (#400)", () => {
+  it("groups collapsed: 'Expand all' is the one target, no cell", () => {
+    const html = render(GROUPED, true);
+    const target = highlighted(html);
+    expect(target.target).toBe(BUDGET_EXPAND_ALL_TARGET);
+    expect(target.inner).toContain("t(reports.collapse.expandAll)");
+    expect(html).not.toContain(BUDGET_CELL_TARGET);
+  });
+
+  it("a group open: this month's cell of its first editable row is the one target", () => {
+    harness.expanded = new Set(["p:10"]);
+    const html = render(GROUPED, true);
+    expect(highlighted(html).target).toBe(BUDGET_CELL_TARGET);
+    expect(ringedMonth(rowOf(html, "Loyer"))).toBe(MARCH);
+    expect(ringedMonth(rowOf(html, "Électricité"))).toBe(-1);
+    // The group's subtotal row has no button to point at.
+    expect(ringedMonth(rowOf(html, "Logement"))).toBe(-1);
+    expect(html).not.toContain(BUDGET_EXPAND_ALL_TARGET);
+  });
+
+  it("every group open: the first editable row of the grid, income first", () => {
+    harness.expanded = new Set(["p:1", "p:10"]);
+    const html = render(GROUPED, true);
+    expect(ringedMonth(rowOf(html, "Salaire"))).toBe(MARCH);
+    expect(count(html, HIGHLIGHT)).toBe(1);
+  });
+
+  it("a category without sub-category shown beside collapsed groups: its cell, 'Expand all' stays plain", () => {
+    const html = render(WITH_STANDALONE, true);
+    expect(highlighted(html).target).toBe(BUDGET_CELL_TARGET);
+    expect(ringedMonth(rowOf(html, "Divers"))).toBe(MARCH);
+    expect(html).toContain("t(reports.collapse.expandAll)");
+    expect(html).not.toContain(BUDGET_EXPAND_ALL_TARGET);
+  });
+
+  it("no groups: no 'Expand all' at all, the first row's cell", () => {
+    const html = render(FLAT, true);
+    expect(html).not.toContain("t(reports.collapse.expandAll)");
+    expect(ringedMonth(rowOf(html, "Divers"))).toBe(MARCH);
+    expect(count(html, HIGHLIGHT)).toBe(1);
+  });
+
+  it("the cell follows the clock's month", () => {
+    vi.setSystemTime(new Date(2026, DECEMBER, 31, 23, 0));
+    expect(ringedMonth(rowOf(render(FLAT, true), "Divers"))).toBe(DECEMBER);
+  });
+
+  it("subtotals at the bottom: still the first editable row shown", () => {
+    vi.stubGlobal("localStorage", { getItem: () => "bottom", setItem: () => undefined });
+    harness.expanded = new Set(["p:10"]);
+    const html = render(GROUPED, true);
+    expect(html).toContain("t(reports.subtotalsOnBottom)");
+    expect(ringedMonth(rowOf(html, "Loyer"))).toBe(MARCH);
+    expect(count(html, HIGHLIGHT)).toBe(1);
+  });
+
+  it("without `onboardingTarget`, nothing is highlighted", () => {
+    for (const expanded of [[], ["p:10"]]) {
+      harness.expanded = new Set(expanded);
+      for (const onboardingTarget of [false, undefined]) {
+        const html = render(GROUPED, onboardingTarget);
+        expect(count(html, HIGHLIGHT)).toBe(0);
+        expect(html).not.toContain("data-onboarding-target");
+      }
+    }
+  });
+
+  it("no row: the grid's 'no category' box, nothing highlighted", () => {
+    const html = render([], true);
+    expect(html).toContain("t(budget.noCategories)");
+    expect(count(html, HIGHLIGHT)).toBe(0);
+  });
+});

src/components/budget/BudgetTable.tsx

@@ -1,11 +1,13 @@
 import { useState, useRef, useEffect, Fragment } from "react";
 import { useTranslation } from "react-i18next";
 import { AlertTriangle, ArrowUpDown, ChevronDown, ChevronRight, ChevronsDownUp, ChevronsUpDown } from "lucide-react";
-import type { BudgetYearRow } from "../../shared/types";
+import type { BudgetOnboardingTargetKind, BudgetYearRow } from "../../shared/types";
 import { reorderRows } from "../../utils/reorderRows";
 import type { CollapseAccessors } from "../../utils/collapsibleRows";
+import { onboardingTargetAttributes } from "../../utils/onboardingPath";
 import { useCollapsibleGroups } from "../../hooks/useCollapsibleGroups";
 import { computeBudgetResults, sumLeavesForType, type BudgetTotals } from "./budgetTableResults";
+import { budgetOnboardingTarget } from "./budgetOnboardingTarget";
 
 const fmt = new Intl.NumberFormat("en-CA", {
   style: "currency",
@@ -37,13 +39,35 @@ const BUDGET_COLLAPSE_ACCESSORS: CollapseAccessors<BudgetYearRow> = {
 
 const BUDGET_EXPANDED_KEY = "budget-grid-expanded";
 
+/** `data-onboarding-target` of the highlighted month cell. */
+export const BUDGET_CELL_TARGET = "budget-cell";
+/** `data-onboarding-target` of the highlighted "Expand all" button. */
+export const BUDGET_EXPAND_ALL_TARGET = "budget-expand-all";
+
 interface BudgetTableProps {
   rows: BudgetYearRow[];
   onUpdatePlanned: (categoryId: number, month: number, amount: number) => void;
   onSplitEvenly: (categoryId: number, annualAmount: number) => void;
+  /**
+   * Highlight the control the getting-started card points at (#400): this
+   * month's cell of the first editable row shown, or "Expand all" while none
+   * is shown (`budgetOnboardingTarget`). One target at a time.
+   */
+  onboardingTarget?: boolean;
+  /**
+   * Told which control that is, at mount and whenever it changes: the
+   * collapse state lives here, and the card's sentence depends on it.
+   */
+  onOnboardingTargetChange?: (kind: BudgetOnboardingTargetKind | null) => void;
 }
 
-export default function BudgetTable({ rows, onUpdatePlanned, onSplitEvenly }: BudgetTableProps) {
+export default function BudgetTable({
+  rows,
+  onUpdatePlanned,
+  onSplitEvenly,
+  onboardingTarget,
+  onOnboardingTargetChange,
+}: BudgetTableProps) {
   const { t } = useTranslation();
   const [editingCell, setEditingCell] = useState<{ categoryId: number; monthIdx: number } | null>(null);
   const [editingAnnual, setEditingAnnual] = useState<{ categoryId: number } | null>(null);
@@ -177,6 +201,30 @@ export default function BudgetTable({ rows, onUpdatePlanned, onSplitEvenly }: Bu
 
   const totalCols = 15; // category + prev year + annual + 12 months
 
+  // The rows each section shows, in the order it shows them: collapse-filtered
+  // (issue #289), then subtotals moved to the chosen side.
+  const shownByType: Record<string, BudgetYearRow[]> = {};
+  for (const type of typeOrder) {
+    shownByType[type] = reorderRows(groups.visible(grouped[type] ?? []), subtotalsOnTop);
+  }
+  const hasGroups = groups.groupCount(rows) > 0;
+  const allExpanded = groups.allExpanded(rows);
+
+  // The control the getting-started card points at (#400, D12): this month's
+  // cell of the first editable row shown, else "Expand all". Its kind goes up
+  // to the page, which picks the card's sentence; the grid stays as the user
+  // left it (the card never unfolds it).
+  const target = budgetOnboardingTarget(
+    typeOrder.flatMap((type) => shownByType[type]),
+    hasGroups,
+    new Date().getMonth(),
+  );
+  const targetKind = target?.kind ?? null;
+  useEffect(() => {
+    onOnboardingTargetChange?.(targetKind);
+  }, [targetKind, onOnboardingTargetChange]);
+  const targetCell = onboardingTarget && target?.kind === "cell" ? target : null;
+
   if (rows.length === 0) {
     return (
       <div className="bg-[var(--card)] rounded-xl p-8 border border-[var(--border)] text-center text-[var(--muted-foreground)]">
@@ -321,6 +369,12 @@ export default function BudgetTable({ rows, onUpdatePlanned, onSplitEvenly }: Bu
                 onClick={() => handleStartEdit(row.category_id, mIdx, val)}
                 title={t("budget.clickToEdit")}
                 className="w-full text-right hover:text-[var(--primary)] hover:bg-[var(--muted)]/40 transition-colors cursor-pointer text-xs rounded px-1 py-0.5"
+                {...onboardingTargetAttributes(
+                  BUDGET_CELL_TARGET,
+                  targetCell !== null &&
+                    targetCell.categoryId === row.category_id &&
+                    targetCell.monthIdx === mIdx,
+                )}
               >
                 {formatSigned(val * sign)}
               </button>
@@ -352,7 +406,7 @@ export default function BudgetTable({ rows, onUpdatePlanned, onSplitEvenly }: Bu
             {t(typeLabelKeys[type])}
           </td>
         </tr>
-        {reorderRows(groups.visible(group), subtotalsOnTop).map((row) => renderRow(row))}
+        {shownByType[type].map((row) => renderRow(row))}
         <tr className="bg-[var(--muted)]/40 border-b border-[var(--border)]">
           <td className="py-2.5 px-3 sticky left-0 bg-[var(--muted)]/40 z-10 text-sm font-semibold">
             {t(typeTotalKeys[type])}
@@ -395,9 +449,6 @@ export default function BudgetTable({ rows, onUpdatePlanned, onSplitEvenly }: Bu
     );
   };
 
-  const hasGroups = groups.groupCount(rows) > 0;
-  const allExpanded = groups.allExpanded(rows);
-
   return (
     <div className="bg-[var(--card)] rounded-xl border border-[var(--border)] overflow-hidden">
       <div className="flex justify-end items-center gap-1 px-3 py-2 border-b border-[var(--border)]">
@@ -406,6 +457,10 @@ export default function BudgetTable({ rows, onUpdatePlanned, onSplitEvenly }: Bu
             type="button"
             onClick={() => (allExpanded ? groups.collapseAll(rows) : groups.expandAll(rows))}
             className="inline-flex items-center gap-1.5 px-2.5 py-1 rounded-lg text-xs font-medium text-[var(--muted-foreground)] hover:bg-[var(--muted)] transition-colors"
+            {...onboardingTargetAttributes(
+              BUDGET_EXPAND_ALL_TARGET,
+              onboardingTarget && target?.kind === "expandAll",
+            )}
           >
             {allExpanded ? <ChevronsDownUp size={13} /> : <ChevronsUpDown size={13} />}
             {allExpanded ? t("reports.collapse.collapseAll") : t("reports.collapse.expandAll")}

src/components/budget/BudgetTable.wiring.test.ts

@@ -0,0 +1,174 @@
+// BudgetTable — how the grid tells the page its target (#400).
+//
+// renderToStaticMarkup runs no effect, so the report would stay unguarded.
+// React's `useState`, `useRef` and `useEffect` are stubbed (technique of
+// OnboardingStepCard.test.tsx and useOnboardingChecklist.wiring.test.ts): the
+// grid runs as a plain function, its state and refs survive from one call to
+// the next as between two renders of a mounted component, and `commit()` runs
+// the effects as React does, an effect only when one of its dependencies
+// changed since its last run. The collapse hook is replaced by the real pure
+// helpers over a state the test sets.
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import type { BudgetYearRow } from "../../shared/types";
+import type { CollapseAccessors } from "../../utils/collapsibleRows";
+
+type Effect = { fn: () => void | (() => void); deps: readonly unknown[] | undefined };
+
+const harness = vi.hoisted(() => ({
+  slots: [] as unknown[],
+  setters: [] as Array<(next: unknown) => void>,
+  cursor: 0,
+  effects: [] as Effect[],
+  /** Dependencies of each effect at its last run. */
+  ran: new Map<number, readonly unknown[] | undefined>(),
+  /** Keys of the open groups (`p:<category id>`): the grid opens collapsed. */
+  expanded: new Set<string>(),
+}));
+
+vi.mock("react", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("react")>();
+  const slot = (init: () => unknown) => {
+    const index = harness.cursor++;
+    if (!(index in harness.slots)) harness.slots[index] = init();
+    return index;
+  };
+  return {
+    ...actual,
+    useState: (init: unknown) => {
+      const index = slot(() => (typeof init === "function" ? (init as () => unknown)() : init));
+      harness.setters[index] ??= (next: unknown) => {
+        harness.slots[index] =
+          typeof next === "function" ? (next as (previous: unknown) => unknown)(harness.slots[index]) : next;
+      };
+      return [harness.slots[index], harness.setters[index]];
+    },
+    useRef: (init: unknown) => harness.slots[slot(() => ({ current: init }))],
+    useEffect: (fn: Effect["fn"], deps?: readonly unknown[]) => {
+      harness.effects.push({ fn, deps });
+    },
+  };
+});
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (k: string) => `t(${k})`, i18n: { language: "fr" } }),
+}));
+vi.mock("../../hooks/useCollapsibleGroups", async () => {
+  const { collapsibleKeys, isCollapsedFor, visibleRows } = await import("../../utils/collapsibleRows");
+  return {
+    useCollapsibleGroups: <T,>(_key: string | null, acc: CollapseAccessors<T>) => {
+      const isCollapsed = (row: T) => isCollapsedFor(harness.expanded, acc.keyOf(row), false);
+      return {
+        visible: (rows: T[]) => visibleRows(rows, acc, isCollapsed),
+        isCollapsed,
+        toggle: () => undefined,
+        expandAll: () => undefined,
+        collapseAll: () => undefined,
+        allExpanded: (rows: T[]) => {
+          const keys = collapsibleKeys(rows, acc);
+          return keys.length > 0 && keys.every((key) => harness.expanded.has(key));
+        },
+        groupCount: (rows: T[]) => collapsibleKeys(rows, acc).length,
+      };
+    },
+  };
+});
+
+import BudgetTable from "./BudgetTable";
+import type { BudgetOnboardingTargetKind } from "../../shared/types";
+
+const leaf = (category_id: number, parent_id: number | null = null): BudgetYearRow => ({
+  category_id,
+  category_name: `Category ${category_id}`,
+  category_color: "#9ca3af",
+  category_type: "expense",
+  parent_id,
+  is_parent: false,
+  depth: parent_id === null ? 0 : 1,
+  months: Array(12).fill(0) as number[],
+  annual: 0,
+  previousYearTotal: 0,
+});
+const GROUPED: BudgetYearRow[] = [{ ...leaf(10), is_parent: true }, leaf(11, 10), leaf(12, 10)];
+
+/** One render of the mounted grid: its hooks are called in the same order each time. */
+function render(
+  rows: BudgetYearRow[],
+  onChange: (kind: BudgetOnboardingTargetKind | null) => void,
+  onboardingTarget?: boolean,
+) {
+  harness.cursor = 0;
+  harness.effects = [];
+  BudgetTable({
+    rows,
+    onUpdatePlanned: () => undefined,
+    onSplitEvenly: () => undefined,
+    onboardingTarget,
+    onOnboardingTargetChange: onChange,
+  });
+}
+
+/** After a render: run each effect whose dependencies changed since its last run, as React does. */
+function commit() {
+  harness.effects.forEach((effect, index) => {
+    const previous = harness.ran.get(index);
+    const changed =
+      !harness.ran.has(index) ||
+      effect.deps === undefined ||
+      previous === undefined ||
+      effect.deps.some((dep, k) => !Object.is(dep, previous[k]));
+    harness.ran.set(index, effect.deps);
+    if (changed) effect.fn();
+  });
+}
+
+beforeEach(() => {
+  harness.slots = [];
+  harness.setters = [];
+  harness.effects = [];
+  harness.ran = new Map();
+  harness.expanded = new Set();
+  vi.stubGlobal("localStorage", { getItem: () => null, setItem: () => undefined });
+});
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+describe("BudgetTable — the target told to the page (#400)", () => {
+  it("tells it once mounted, then only when it changes", () => {
+    const onChange = vi.fn();
+    render(GROUPED, onChange, true);
+    commit();
+    expect(onChange.mock.calls).toEqual([["expandAll"]]);
+
+    // Another render with nothing changed: not told again.
+    render(GROUPED, onChange, true);
+    commit();
+    expect(onChange).toHaveBeenCalledTimes(1);
+
+    // The user opens the group: an editable row shows.
+    harness.expanded = new Set(["p:10"]);
+    render(GROUPED, onChange, true);
+    commit();
+    render(GROUPED, onChange, true);
+    commit();
+    expect(onChange.mock.calls).toEqual([["expandAll"], ["cell"]]);
+
+    // The rows are gone: nothing to point at.
+    render([], onChange, true);
+    commit();
+    expect(onChange.mock.calls).toEqual([["expandAll"], ["cell"], [null]]);
+  });
+
+  it("tells it before any highlight is asked: the page needs it for the card's sentence", () => {
+    const onChange = vi.fn();
+    render([leaf(30)], onChange);
+    commit();
+    expect(onChange.mock.calls).toEqual([["cell"]]);
+  });
+
+  it("tells nothing during a render", () => {
+    const onChange = vi.fn();
+    render(GROUPED, onChange, true);
+    expect(onChange).not.toHaveBeenCalled();
+  });
+});

src/components/budget/budgetOnboardingTarget.test.ts

@@ -0,0 +1,100 @@
+import { describe, it, expect } from "vitest";
+import { budgetOnboardingTarget } from "./budgetOnboardingTarget";
+import type { BudgetYearRow } from "../../shared/types";
+
+/** A grid row; a leaf at the top level unless `overrides` says otherwise. */
+const row = (category_id: number, overrides: Partial<BudgetYearRow> = {}): BudgetYearRow => ({
+  category_id,
+  category_name: `Category ${category_id}`,
+  category_color: "#9ca3af",
+  category_type: "expense",
+  parent_id: null,
+  is_parent: false,
+  depth: 0,
+  months: Array(12).fill(0) as number[],
+  annual: 0,
+  previousYearTotal: 0,
+  ...overrides,
+});
+/** A group's subtotal row: read-only. */
+const group = (category_id: number, overrides: Partial<BudgetYearRow> = {}) =>
+  row(category_id, { is_parent: true, ...overrides });
+/** A leaf under `parent_id`. */
+const child = (category_id: number, parent_id: number, depth = 1) =>
+  row(category_id, { parent_id, depth });
+
+const OCTOBER = 9;
+
+describe("budgetOnboardingTarget (#400, D12)", () => {
+  it("groups collapsed: 'Expand all', the editable rows being folded away", () => {
+    // Collapsed, the grid shows its top-level subtotals only.
+    expect(budgetOnboardingTarget([group(10), group(20)], true, OCTOBER)).toEqual({
+      kind: "expandAll",
+    });
+    // A group open on a sub-group still folded: still no editable row shown.
+    expect(
+      budgetOnboardingTarget([group(10), group(11, { parent_id: 10, depth: 1 })], true, OCTOBER),
+    ).toEqual({ kind: "expandAll" });
+  });
+
+  it("the first leaf shown: its cell in the given month, past the subtotal rows above it", () => {
+    expect(budgetOnboardingTarget([group(10), child(13, 10), child(14, 10)], true, OCTOBER)).toEqual({
+      kind: "cell",
+      categoryId: 13,
+      monthIdx: OCTOBER,
+    });
+    // A sub-group's subtotal before the leaves is skipped too.
+    expect(
+      budgetOnboardingTarget(
+        [group(10), group(11, { parent_id: 10, depth: 1 }), child(15, 11, 2)],
+        true,
+        OCTOBER,
+      ),
+    ).toEqual({ kind: "cell", categoryId: 15, monthIdx: OCTOBER });
+  });
+
+  it("subtotals at the bottom: the first leaf, not the subtotal under it", () => {
+    expect(budgetOnboardingTarget([child(13, 10), child(14, 10), group(10)], true, OCTOBER)).toEqual({
+      kind: "cell",
+      categoryId: 13,
+      monthIdx: OCTOBER,
+    });
+  });
+
+  it("a '(direct)' leaf is a leaf: its cell, though it shares its group's category id", () => {
+    expect(
+      budgetOnboardingTarget([group(10), row(10, { parent_id: 10, depth: 1 }), child(13, 10)], true, 0),
+    ).toEqual({ kind: "cell", categoryId: 10, monthIdx: 0 });
+  });
+
+  it("a leaf shown while the groups are collapsed (a category without sub-category): already a cell", () => {
+    expect(budgetOnboardingTarget([group(10), row(30), group(20)], true, OCTOBER)).toEqual({
+      kind: "cell",
+      categoryId: 30,
+      monthIdx: OCTOBER,
+    });
+  });
+
+  it("without groups: the first row's cell", () => {
+    expect(budgetOnboardingTarget([row(30), row(31)], false, OCTOBER)).toEqual({
+      kind: "cell",
+      categoryId: 30,
+      monthIdx: OCTOBER,
+    });
+  });
+
+  it("no row: nothing to point at", () => {
+    expect(budgetOnboardingTarget([], false, OCTOBER)).toBeNull();
+    expect(budgetOnboardingTarget([], false, 0)).toBeNull();
+  });
+
+  it("keeps the month it is given, January to December", () => {
+    for (const monthIdx of [0, 5, 11]) {
+      expect(budgetOnboardingTarget([row(30)], false, monthIdx)).toEqual({
+        kind: "cell",
+        categoryId: 30,
+        monthIdx,
+      });
+    }
+  });
+});

src/components/budget/budgetOnboardingTarget.ts

@@ -0,0 +1,33 @@
+import type { BudgetYearRow } from "../../shared/types";
+
+/**
+ * The control of the budget grid that the getting-started card points at
+ * (#400): the month cell of an editable row, or "Expand all".
+ */
+export type BudgetOnboardingTarget =
+  | { kind: "cell"; categoryId: number; monthIdx: number }
+  | { kind: "expandAll" };
+
+/**
+ * Which control of the budget grid the Budget step card points at (#400, D12).
+ *
+ * `visibleRows` are the rows the grid shows, in the order it shows them. A
+ * subtotal row is read-only and a row folded under a collapsed group is not on
+ * screen, so the target is:
+ * - the `monthIdx` cell of the first leaf row shown;
+ * - otherwise "Expand all" when the grid has groups: its editable rows are
+ *   folded away, and the card never unfolds them for the user;
+ * - otherwise null: no row at all, nothing to point at.
+ *
+ * Pure (no React, no storage), like `budgetTableResults.ts`, so the rule is
+ * tested without rendering the grid and its collapse hook.
+ */
+export function budgetOnboardingTarget(
+  visibleRows: readonly BudgetYearRow[],
+  hasGroups: boolean,
+  monthIdx: number,
+): BudgetOnboardingTarget | null {
+  const leaf = visibleRows.find((row) => !row.is_parent);
+  if (leaf) return { kind: "cell", categoryId: leaf.category_id, monthIdx };
+  return hasGroups ? { kind: "expandAll" } : null;
+}

src/components/layout/AppShell.render.test.tsx

@@ -70,11 +70,16 @@ const loaded = (snapshot: OnboardingSnapshot): OnboardingChecklistState =>
   ].reduce(onboardingChecklistReducer, initialOnboardingChecklistState);
 
 /** What `useOnboarding()` gives at `pathname` for `state`, derived as the provider does. */
-function pathAt(pathname: string, state: OnboardingChecklistState, budgetReady = true): OnboardingValue {
+function pathAt(
+  pathname: string,
+  state: OnboardingChecklistState,
+  budgetReady = true,
+  budgetAllowed = true,
+): OnboardingValue {
   const checklist = state.counters
     ? computeChecklist(state.counters, {
         importFolderSet: state.importFolderSet,
-        budgetAllowed: true,
+        budgetAllowed,
         skipped: state.skipped,
       })
     : null;
@@ -150,18 +155,6 @@ describe("AppShell — the getting-started banner (#397)", () => {
     }
   });
 
-  it.each([["/budget", BUDGET_LEFT]] as const)(
-    "keeps the banner on %s, the page of the next step, while no step card is delivered",
-    (pathname, snapshot) => {
-      expect(CARD_PAGES.has(pathname)).toBe(false);
-      const value = pathAt(pathname, loaded(snapshot));
-      expect(value.nextStep?.to).toBe(pathname);
-      const html = renderWith(pathname, value);
-      expect(html).toContain(BANNER);
-      expect(html).toContain(`href="${pathname}"`);
-    },
-  );
-
   it("gives /import, the page of the next step, its step card instead of the banner (#398)", () => {
     expect(CARD_PAGES.has("/import")).toBe(true);
     const value = pathAt("/import", loaded(NEW_PROFILE));
@@ -184,6 +177,28 @@ describe("AppShell — the getting-started banner (#397)", () => {
     expect(renderAt("/reports", loaded(IMPORTED))).toContain('href="/transactions"');
   });
 
+  it("gives /budget, the page of the next step, its step card instead of the banner (#400)", () => {
+    expect(CARD_PAGES.has("/budget")).toBe(true);
+    const value = pathAt("/budget", loaded(BUDGET_LEFT));
+    expect(value.nextStep?.to).toBe("/budget");
+    expect(value.mode).toBe("card");
+    expect(value.cardPage).toBe("/budget");
+    expect(renderWith("/budget", value)).not.toContain(BANNER);
+    // Anywhere else, the same profile keeps the banner and its link to /budget.
+    expect(renderAt("/reports", loaded(BUDGET_LEFT))).toContain('href="/budget"');
+  });
+
+  it("in the Free edition, /budget never gets a card and the path ends at 5/5 (#400)", () => {
+    const value = pathAt("/budget", loaded(BUDGET_LEFT), true, false);
+    expect(value.checklist?.total).toBe(5);
+    expect(value.nextStep).toBeNull();
+    expect(value.cardPage).toBeNull();
+    expect(value.mode).toBe("complete");
+    const html = renderWith("/budget", value);
+    expect(html).toContain(BANNER);
+    expect(html).toContain("t(onboarding.banner.complete)");
+  });
+
   it("shows nothing on a page that carries a step card", () => {
     const value = { ...pathAt("/import", loaded(NEW_PROFILE)), mode: "card" as const, cardPage: "/import" };
     expect(renderWith("/import", value)).not.toContain(BANNER);

src/i18n/locales/en.json

@@ -93,6 +93,10 @@
       "transactions": {
         "uncategorized": "Only {{filter, lowercase}} transactions are shown. Click the category of one of them and pick one from the list. Simpl'Résultat keeps your choice, and automatic categorization will not replace it.",
         "all": "Click a transaction's category and pick one from the list. Simpl'Résultat keeps your choice, and automatic categorization will not replace it."
+      },
+      "budget": {
+        "collapsed": "Click {{expand}} to show your categories, then click a month and enter an amount. Enter saves; Tab saves and moves to the next month.",
+        "flat": "Click a month and enter an amount. Enter saves; Tab saves and moves to the next month."
       }
     },
     "state": {

src/i18n/locales/fr.json

@@ -93,6 +93,10 @@
       "transactions": {
         "uncategorized": "Seules les transactions {{filter, lowercase}} sont affichées. Cliquez sur la catégorie de l'une d'elles et choisissez-en une dans la liste. Simpl'Résultat retient ce choix, et la catégorisation automatique ne le remplacera pas.",
         "all": "Cliquez sur la catégorie d'une transaction et choisissez-en une dans la liste. Simpl'Résultat retient ce choix, et la catégorisation automatique ne le remplacera pas."
+      },
+      "budget": {
+        "collapsed": "Cliquez {{expand}} pour afficher vos catégories, puis cliquez sur un mois et saisissez un montant. Entrée enregistre ; Tab enregistre et passe au mois suivant.",
+        "flat": "Cliquez sur un mois et saisissez un montant. Entrée enregistre ; Tab enregistre et passe au mois suivant."
       }
     },
     "state": {

src/pages/BudgetPage.render.test.tsx

@@ -0,0 +1,194 @@
+// BudgetPage and its getting-started card (#400). No jsdom: react-dom/server
+// renders in vitest's node environment. The budget is a fake `useBudget()`
+// over its real initial state, the path a fake `useOnboarding()` built from the
+// real checklist, and the grid is the real BudgetTable. A static render runs
+// no effect, so the grid never reports its target here (the report and what
+// the page does with it are in BudgetPage.wiring.test.ts). What is pinned is
+// where the card sits and what it says before and after the step is checked.
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+import { MemoryRouter } from "react-router-dom";
+
+// The budget, collapse and preference services pull the database: stub the connection.
+vi.mock("../services/db", () => ({ getDb: vi.fn(), withTransaction: vi.fn() }));
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({
+    t: (k: string, o?: Record<string, unknown>) =>
+      o ? `t(${k}[${Object.entries(o).map(([a, b]) => `${a}=${String(b)}`).join(",")}])` : `t(${k})`,
+    i18n: { language: "fr" },
+  }),
+}));
+vi.mock("../components/shared/PageHelp", () => ({ PageHelp: () => null }));
+
+const harness = vi.hoisted(() => ({ budget: null as unknown, onboarding: null as unknown }));
+
+vi.mock("../contexts/OnboardingContext", () => ({ useOnboarding: () => harness.onboarding }));
+vi.mock("../hooks/useBudget", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../hooks/useBudget")>()),
+  useBudget: () => harness.budget,
+}));
+
+import BudgetPage from "./BudgetPage";
+import { initialBudgetState, type BudgetState } from "../hooks/useBudget";
+import type { OnboardingValue } from "../hooks/useOnboardingChecklist";
+import { computeChecklist } from "../utils/onboardingChecklist";
+import { nextStep } from "../utils/onboardingPath";
+import type { BudgetYearRow, OnboardingCounters } from "../shared/types";
+
+/** Steps 2 to 5 done: the next step is the budget. */
+const BUDGET_LEFT: OnboardingCounters = {
+  sources: 1,
+  imports: 1,
+  manualCategorized: 1,
+  budgetEntries: 0,
+  transactions: 41,
+};
+/** A first amount saved: every step done. */
+const BUDGETED: OnboardingCounters = { ...BUDGET_LEFT, budgetEntries: 1 };
+
+const ROWS: BudgetYearRow[] = [
+  {
+    category_id: 10,
+    category_name: "Logement",
+    category_color: "#9ca3af",
+    category_type: "expense",
+    parent_id: null,
+    is_parent: true,
+    depth: 0,
+    months: Array(12).fill(0) as number[],
+    annual: 0,
+    previousYearTotal: 0,
+  },
+  {
+    category_id: 11,
+    category_name: "Loyer",
+    category_color: "#9ca3af",
+    category_type: "expense",
+    parent_id: 10,
+    is_parent: false,
+    depth: 1,
+    months: Array(12).fill(0) as number[],
+    annual: 0,
+    previousYearTotal: 0,
+  },
+];
+
+/** The budget after its first read, with `overrides`. */
+function budget(overrides: Partial<BudgetState> = {}) {
+  const state: BudgetState = { ...initialBudgetState(), rows: ROWS, totalInDb: 41, ...overrides };
+  const noop = vi.fn();
+  return new Proxy({ state } as Record<string, unknown>, {
+    get: (target, key) => (key in target ? target[key as string] : noop),
+  });
+}
+
+/** The path latched on /budget (card mode), as the provider shares it. */
+function path(counters: OnboardingCounters, overrides: Partial<OnboardingValue> = {}): OnboardingValue {
+  const checklist = computeChecklist(counters, { importFolderSet: true, budgetAllowed: true });
+  return {
+    status: "ready",
+    checklist,
+    counters,
+    hidden: false,
+    budgetReady: true,
+    nextStep: nextStep(checklist),
+    mode: "card",
+    cardPage: "/budget",
+    hide: vi.fn(async () => undefined),
+    show: vi.fn(async () => undefined),
+    skip: vi.fn(async () => undefined),
+    resume: vi.fn(async () => undefined),
+    refresh: vi.fn(async () => undefined),
+    ...overrides,
+  };
+}
+
+const render = () =>
+  renderToStaticMarkup(
+    <MemoryRouter initialEntries={["/budget"]}>
+      <BudgetPage />
+    </MemoryRouter>,
+  );
+
+const CARD = 'aria-label="t(onboarding.banner.label)"';
+const HIGHLIGHT = 'data-onboarding-highlight="true"';
+const DIM = 'class="opacity-50 pointer-events-none"';
+const count = (html: string, needle: string) => html.split(needle).length - 1;
+/**
+ * The card's sentence: the paragraph right after the card's own title, null
+ * without one (the empty state below has a title and a paragraph too).
+ */
+function sentence(html: string): string | null {
+  const title = html.indexOf("</h2>", html.indexOf(CARD));
+  return html.slice(title).match(/^<\/h2><p [^>]*>(.*?)<\/p>/)?.[1] ?? null;
+}
+
+beforeEach(() => {
+  harness.budget = budget();
+  harness.onboarding = path(BUDGET_LEFT);
+  vi.stubGlobal("localStorage", { getItem: () => null, setItem: () => undefined });
+});
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+describe("BudgetPage — the step card (#400)", () => {
+  it("renders the card first, before the page's heading, at its place in the path", () => {
+    const html = render();
+    expect(count(html, CARD)).toBe(1);
+    expect(html.indexOf(CARD)).toBeLessThan(html.indexOf("<h1"));
+    expect(html).toContain("t(onboarding.card.stepOf[n=6,total=6])");
+    expect(html).toContain("t(onboarding.checklist.items.budget)");
+    expect(html).toContain("t(onboarding.card.skip)");
+    // The grid is there, below the card.
+    expect(html.indexOf("Logement")).toBeGreaterThan(html.indexOf(CARD));
+  });
+
+  it("before the grid reports its target: the title and 'Skip this step', no sentence, no ring", () => {
+    const html = render();
+    expect(sentence(html)).toBeNull();
+    expect(count(html, HIGHLIGHT)).toBe(0);
+  });
+
+  it("keeps the card out of the loading dim, which still covers the page", () => {
+    harness.budget = budget({ isLoading: true });
+    const html = render();
+    expect(count(html, DIM)).toBe(1);
+    expect(html.indexOf("t(onboarding.card.skip)")).toBeLessThan(html.indexOf(DIM));
+    expect(html.indexOf(DIM)).toBeLessThan(html.indexOf("<h1"));
+  });
+
+  it("a first amount saved: the card stays, says 'Done.' and ends the path", () => {
+    harness.onboarding = path(BUDGETED);
+    const html = render();
+    expect(count(html, CARD)).toBe(1);
+    expect(html).toMatch(/<p role="status"[^>]*>.*t\(onboarding\.card\.done\)/);
+    expect(html).toContain("t(onboarding.banner.complete)");
+    expect(html).toContain("t(onboarding.banner.openGuide)");
+    expect(html).not.toContain("t(onboarding.card.skip)");
+    expect(count(html, HIGHLIGHT)).toBe(0);
+  });
+
+  it("a profile without transactions: the card above the 'import first' state", () => {
+    harness.budget = budget({ rows: [], totalInDb: 0 });
+    const html = render();
+    expect(html).toContain("t(budget.empty.title)");
+    expect(html.indexOf(CARD)).toBeLessThan(html.indexOf("t(budget.empty.title)"));
+    expect(html).toContain("t(onboarding.card.skip)");
+    expect(sentence(html)).toBeNull();
+  });
+
+  it("no card when the path is not in card mode on this page", () => {
+    for (const overrides of [
+      { mode: "banner" as const, cardPage: null },
+      { mode: "none" as const, cardPage: null },
+      { mode: "card" as const, cardPage: "/transactions" },
+    ]) {
+      harness.onboarding = path(BUDGET_LEFT, overrides);
+      const html = render();
+      expect(html).not.toContain(CARD);
+      expect(html).toContain("Logement");
+    }
+  });
+});

src/pages/BudgetPage.tsx

@@ -1,16 +1,24 @@
+import { useState } from "react";
 import { useTranslation } from "react-i18next";
+import { useLocation } from "react-router-dom";
 import { Calculator } from "lucide-react";
 import { PageHelp } from "../components/shared/PageHelp";
 import EmptyState from "../components/shared/EmptyState";
 import FilterPanel from "../components/reports/FilterPanel";
+import OnboardingStepCard from "../components/onboarding/OnboardingStepCard";
+import { useOnboarding } from "../contexts/OnboardingContext";
+import { budgetCardModel, showsStepCard } from "../utils/onboardingPath";
 import { useBudget, showsEmptyState } from "../hooks/useBudget";
 import { useReportsPeriod } from "../hooks/useReportsPeriod";
 import YearNavigator from "../components/budget/YearNavigator";
 import BudgetTable from "../components/budget/BudgetTable";
 import TemplateActions from "../components/budget/TemplateActions";
+import type { BudgetOnboardingTargetKind } from "../shared/types";
 
 export default function BudgetPage() {
   const { t } = useTranslation();
+  const { pathname } = useLocation();
+  const onboarding = useOnboarding();
   const { accountIds, setAccountIds } = useReportsPeriod();
   const {
     state,
@@ -22,6 +30,9 @@ export default function BudgetPage() {
     applyTemplateAllMonths,
     deleteTemplate,
   } = useBudget();
+  // What the grid points the getting-started card at (#400). The collapse
+  // state lives in BudgetTable, which reports its target here.
+  const [gridTarget, setGridTarget] = useState<BudgetOnboardingTargetKind | null>(null);
 
   const { year, rows, templates, accounts, isLoading, isSaving, error } = state;
 
@@ -30,52 +41,67 @@ export default function BudgetPage() {
   // actions stay.
   const isEmptyProfile = showsEmptyState(state);
 
+  // The getting-started card follows the grid (#400). Its target is
+  // highlighted only while the card is on screen: a ring needs the card that
+  // explains it.
+  const cardModel = budgetCardModel({ target: gridTarget }, onboarding.checklist);
+  const highlight =
+    cardModel.target !== null && showsStepCard(onboarding.mode, onboarding.cardPage, pathname);
+
   return (
-    <div className={isLoading ? "opacity-50 pointer-events-none" : ""}>
-      <div className="relative flex flex-col sm:flex-row sm:items-center sm:justify-between gap-4 mb-4">
-        <div className="flex items-center gap-3">
-          <h1 className="text-2xl font-bold">{t("budget.title")}</h1>
-          <PageHelp helpKey="budget" />
+    <div>
+      {/* Outside the loading dim: the grid reloads after every save, right
+          when the card says "Done.". */}
+      <OnboardingStepCard model={cardModel} />
+
+      <div className={isLoading ? "opacity-50 pointer-events-none" : ""}>
+        <div className="relative flex flex-col sm:flex-row sm:items-center sm:justify-between gap-4 mb-4">
+          <div className="flex items-center gap-3">
+            <h1 className="text-2xl font-bold">{t("budget.title")}</h1>
+            <PageHelp helpKey="budget" />
+          </div>
+          <TemplateActions
+            templates={templates}
+            onApply={applyTemplate}
+            onApplyAllMonths={applyTemplateAllMonths}
+            onSave={saveTemplate}
+            onDelete={deleteTemplate}
+            disabled={isSaving}
+          />
         </div>
-        <TemplateActions
-          templates={templates}
-          onApply={applyTemplate}
-          onApplyAllMonths={applyTemplateAllMonths}
-          onSave={saveTemplate}
-          onDelete={deleteTemplate}
-          disabled={isSaving}
-        />
+
+        {error && (
+          <div className="mb-4 p-3 rounded-lg bg-[var(--negative)]/10 text-[var(--negative)] text-sm border border-[var(--negative)]/20">
+            {error}
+          </div>
+        )}
+
+        {isEmptyProfile ? (
+          <EmptyState
+            icon={<Calculator size={40} />}
+            title={t("budget.empty.title")}
+            description={t("budget.empty.description")}
+            primaryAction={{ label: t("budget.empty.cta"), to: "/import" }}
+          />
+        ) : (
+          <>
+            <FilterPanel
+              temporalControl={<YearNavigator year={year} onNavigate={navigateYear} />}
+              accountIds={accountIds}
+              onAccountIdsChange={setAccountIds}
+              accounts={accounts}
+            />
+
+            <BudgetTable
+              rows={rows}
+              onUpdatePlanned={updatePlanned}
+              onSplitEvenly={splitEvenly}
+              onboardingTarget={highlight}
+              onOnboardingTargetChange={setGridTarget}
+            />
+          </>
+        )}
       </div>
-
-      {error && (
-        <div className="mb-4 p-3 rounded-lg bg-[var(--negative)]/10 text-[var(--negative)] text-sm border border-[var(--negative)]/20">
-          {error}
-        </div>
-      )}
-
-      {isEmptyProfile ? (
-        <EmptyState
-          icon={<Calculator size={40} />}
-          title={t("budget.empty.title")}
-          description={t("budget.empty.description")}
-          primaryAction={{ label: t("budget.empty.cta"), to: "/import" }}
-        />
-      ) : (
-        <>
-          <FilterPanel
-            temporalControl={<YearNavigator year={year} onNavigate={navigateYear} />}
-            accountIds={accountIds}
-            onAccountIdsChange={setAccountIds}
-            accounts={accounts}
-          />
-
-          <BudgetTable
-            rows={rows}
-            onUpdatePlanned={updatePlanned}
-            onSplitEvenly={splitEvenly}
-          />
-        </>
-      )}
     </div>
   );
 }

src/pages/BudgetPage.wiring.test.ts

@@ -0,0 +1,186 @@
+// BudgetPage — what the page does with the grid's target (#400).
+//
+// A static render runs no effect, so the grid never reports there. React's
+// `useState` is stubbed (technique of AppShell.slot.test.tsx): the page runs
+// as a plain function, its state survives from one call to the next as
+// between two renders of a mounted component, and its setters keep their
+// identity as React's do. The test plays the grid by calling the callback the
+// page hands it, then reads what the page hands the card and the grid.
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { isValidElement, type ReactElement, type ReactNode } from "react";
+
+const harness = vi.hoisted(() => ({
+  slots: [] as unknown[],
+  setters: [] as Array<(next: unknown) => void>,
+  cursor: 0,
+  pathname: "/budget",
+  onboarding: null as unknown,
+  budget: null as unknown,
+}));
+
+vi.mock("react", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("react")>();
+  return {
+    ...actual,
+    useState: (init: unknown) => {
+      const index = harness.cursor++;
+      if (!(index in harness.slots)) {
+        harness.slots[index] = typeof init === "function" ? (init as () => unknown)() : init;
+      }
+      harness.setters[index] ??= (next: unknown) => {
+        harness.slots[index] =
+          typeof next === "function" ? (next as (previous: unknown) => unknown)(harness.slots[index]) : next;
+      };
+      return [harness.slots[index], harness.setters[index]];
+    },
+  };
+});
+vi.mock("react-router-dom", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("react-router-dom")>()),
+  useLocation: () => ({ pathname: harness.pathname }),
+}));
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (k: string) => `t(${k})`, i18n: { language: "fr" } }),
+}));
+// The page's modules pull the database: stub the connection.
+vi.mock("../services/db", () => ({ getDb: vi.fn(), withTransaction: vi.fn() }));
+vi.mock("../contexts/OnboardingContext", () => ({ useOnboarding: () => harness.onboarding }));
+vi.mock("../hooks/useReportsPeriod", () => ({
+  useReportsPeriod: () => ({ accountIds: [], setAccountIds: () => undefined }),
+}));
+vi.mock("../hooks/useBudget", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../hooks/useBudget")>()),
+  useBudget: () => harness.budget,
+}));
+
+import BudgetPage from "./BudgetPage";
+import BudgetTable from "../components/budget/BudgetTable";
+import OnboardingStepCard from "../components/onboarding/OnboardingStepCard";
+import { initialBudgetState, type BudgetState } from "../hooks/useBudget";
+import type { OnboardingValue } from "../hooks/useOnboardingChecklist";
+import { computeChecklist } from "../utils/onboardingChecklist";
+import { budgetCardModel, nextStep, type BudgetCardModel } from "../utils/onboardingPath";
+import type { BudgetOnboardingTargetKind, OnboardingCounters } from "../shared/types";
+
+type AnyElement = ReactElement<Record<string, unknown> & { children?: ReactNode }>;
+
+function find(node: ReactNode, pred: (el: AnyElement) => boolean): AnyElement[] {
+  if (Array.isArray(node)) return node.flatMap((n) => find(n, pred));
+  if (!isValidElement(node)) return [];
+  const el = node as AnyElement;
+  return [...(pred(el) ? [el] : []), ...find(el.props.children, pred)];
+}
+
+/** Steps 2 to 5 done: the next step is the budget. */
+const BUDGET_LEFT: OnboardingCounters = {
+  sources: 1,
+  imports: 1,
+  manualCategorized: 1,
+  budgetEntries: 0,
+  transactions: 41,
+};
+
+/** The path latched on /budget (card mode), as the provider shares it. */
+function path(counters: OnboardingCounters, overrides: Partial<OnboardingValue> = {}): OnboardingValue {
+  const checklist = computeChecklist(counters, { importFolderSet: true, budgetAllowed: true });
+  return {
+    status: "ready",
+    checklist,
+    counters,
+    hidden: false,
+    budgetReady: true,
+    nextStep: nextStep(checklist),
+    mode: "card",
+    cardPage: "/budget",
+    hide: vi.fn(async () => undefined),
+    show: vi.fn(async () => undefined),
+    skip: vi.fn(async () => undefined),
+    resume: vi.fn(async () => undefined),
+    refresh: vi.fn(async () => undefined),
+    ...overrides,
+  };
+}
+
+/** One render of the mounted page: its hooks are read in the same order each time. */
+function render() {
+  harness.cursor = 0;
+  const page = BudgetPage() as AnyElement;
+  const [card] = find(page, (el) => el.type === OnboardingStepCard);
+  const [grid] = find(page, (el) => el.type === BudgetTable);
+  return {
+    page,
+    model: card.props.model as BudgetCardModel,
+    highlight: grid.props.onboardingTarget as boolean,
+    report: grid.props.onOnboardingTargetChange as (kind: BudgetOnboardingTargetKind | null) => void,
+  };
+}
+
+beforeEach(() => {
+  harness.slots = [];
+  harness.setters = [];
+  harness.pathname = "/budget";
+  harness.onboarding = path(BUDGET_LEFT);
+  const state: BudgetState = { ...initialBudgetState(), totalInDb: 41 };
+  harness.budget = new Proxy({ state } as Record<string, unknown>, {
+    get: (target, key) => (key in target ? target[key as string] : vi.fn()),
+  });
+});
+
+describe("BudgetPage — the grid's target and the card (#400)", () => {
+  it("renders the card as the page's first child, ahead of its heading", () => {
+    const { page } = render();
+    const children = page.props.children as ReactNode[];
+    expect((children[0] as AnyElement).type).toBe(OnboardingStepCard);
+    expect(find(children[0], (el) => el.type === "h1")).toHaveLength(0);
+    expect(find(children.slice(1), (el) => el.type === "h1")).toHaveLength(1);
+  });
+
+  it("follows what the grid reports: its sentence, and the ring once a target is known", () => {
+    const checklist = (harness.onboarding as OnboardingValue).checklist;
+    let view = render();
+    expect(view.model).toEqual(budgetCardModel({ target: null }, checklist));
+    expect(view.highlight).toBe(false);
+
+    view.report("expandAll");
+    view = render();
+    expect(view.model.text?.key).toBe("onboarding.card.budget.collapsed");
+    expect(view.highlight).toBe(true);
+
+    view.report("cell");
+    view = render();
+    expect(view.model.text?.key).toBe("onboarding.card.budget.flat");
+    expect(view.highlight).toBe(true);
+
+    view.report(null);
+    view = render();
+    expect(view.model.text).toBeNull();
+    expect(view.highlight).toBe(false);
+  });
+
+  it("asks for no ring while the card is not on screen", () => {
+    for (const overrides of [
+      { mode: "banner" as const, cardPage: null },
+      { mode: "none" as const, cardPage: null },
+      { mode: "complete" as const, cardPage: null },
+      { mode: "card" as const, cardPage: "/transactions" },
+    ]) {
+      harness.slots = [];
+      harness.setters = [];
+      harness.onboarding = path(BUDGET_LEFT, overrides);
+      render().report("cell");
+      expect(render().highlight, JSON.stringify(overrides)).toBe(false);
+    }
+  });
+
+  it("asks for no ring once the step is checked: the card says 'Done.'", () => {
+    harness.onboarding = path({ ...BUDGET_LEFT, budgetEntries: 1 });
+    render().report("cell");
+    const view = render();
+    expect(view.model).toEqual({ text: null, done: true, target: null });
+    expect(view.highlight).toBe(false);
+  });
+
+  it("hands the grid the same callback at every render, so the grid does not report at every render", () => {
+    expect(render().report).toBe(render().report);
+  });
+});

src/shared/types/index.ts

@@ -1021,3 +1021,19 @@ export interface ImportCardInput {
   /** Transactions the import added (`ImportReport.importedCount`), null outside the `report` step. */
   importedCount: number | null;
 }
+
+/**
+ * The control of the budget grid that the Budget step card points at (#400):
+ * a month cell of an editable row, or "Expand all" while none is shown.
+ */
+export type BudgetOnboardingTargetKind = "cell" | "expandAll";
+
+/**
+ * What the Budget page's step card reads of the grid (#400). The collapse
+ * state lives in `BudgetTable`, which reports its target to the page;
+ * `budgetCardModel` turns it into the card.
+ */
+export interface BudgetCardInput {
+  /** The grid's target; null without one (no grid on the page, no row) or before the grid says. */
+  target: BudgetOnboardingTargetKind | null;
+}

src/utils/onboardingPath.test.ts

@@ -4,6 +4,7 @@ import { computeChecklist, type Checklist } from "./onboardingChecklist";
 import {
   CARD_PAGES,
   bannerMode,
+  budgetCardModel,
   cardNext,
   cardStep,
   importCardModel,
@@ -16,6 +17,7 @@ import {
   stepsOfPage,
   transactionsCardModel,
   type BannerModeInput,
+  type BudgetCardModel,
   type ImportCardModel,
   type StepCardText,
   type TransactionsCardModel,
@@ -61,6 +63,17 @@ const step = (key: ChecklistItemKey): ChecklistItem =>
 
 const ALL_CARD_PAGES: ReadonlySet<string> = new Set(["/import", "/transactions", "/budget"]);
 
+/** A sentence of a card as StepCard renders it, through the app's real i18n. */
+const render = (text: StepCardText | null, lng: "fr" | "en") =>
+  text &&
+  i18n.t(text.key, {
+    lng,
+    ...text.values,
+    ...Object.fromEntries(
+      Object.entries(text.labels ?? {}).map(([name, key]) => [name, i18n.t(key, { lng })]),
+    ),
+  });
+
 describe("nextStep (#396)", () => {
   it("is the folder step on a new profile", () => {
     expect(nextStep(checklistOf(zero))?.key).toBe("importFolder");
@@ -346,7 +359,7 @@ describe("stepNavState (#397)", () => {
   });
 });
 
-describe("CARD_PAGES (#398, #399)", () => {
+describe("CARD_PAGES (#398, #399, #400)", () => {
   it("carries the Import page", () => {
     expect(CARD_PAGES.has("/import")).toBe(true);
   });
@@ -354,6 +367,10 @@ describe("CARD_PAGES (#398, #399)", () => {
   it("carries the Transactions page", () => {
     expect(CARD_PAGES.has("/transactions")).toBe(true);
   });
+
+  it("carries the Budget page", () => {
+    expect(CARD_PAGES.has("/budget")).toBe(true);
+  });
 });
 
 describe("showsStepCard (#398)", () => {
@@ -594,17 +611,6 @@ describe("transactionsCardModel (#399)", () => {
     target: "firstRowCategory",
   };
 
-  /** A sentence of the card as StepCard renders it, through the app's real i18n. */
-  const render = (text: StepCardText | null, lng: "fr" | "en") =>
-    text &&
-    i18n.t(text.key, {
-      lng,
-      ...text.values,
-      ...Object.fromEntries(
-        Object.entries(text.labels ?? {}).map(([name, key]) => [name, i18n.t(key, { lng })]),
-      ),
-    });
-
   it("only the uncategorized transactions listed: says so, the filter named by its own label", () => {
     expect(transactionsCardModel({ uncategorizedOnly: true }, imported)).toEqual(UNCATEGORIZED);
   });
@@ -655,6 +661,76 @@ describe("transactionsCardModel (#399)", () => {
   });
 });
 
+describe("budgetCardModel (#400)", () => {
+  /** Steps 2 to 5 done: the next step is the budget. */
+  const budgetLeft = checklistOf(upToManual, { importFolderSet: true });
+  const COLLAPSED: BudgetCardModel = {
+    text: {
+      key: "onboarding.card.budget.collapsed",
+      labels: { expand: "reports.collapse.expandAll" },
+    },
+    done: false,
+    target: "expandAll",
+  };
+  const FLAT: BudgetCardModel = {
+    text: { key: "onboarding.card.budget.flat" },
+    done: false,
+    target: "cell",
+  };
+  const DONE: BudgetCardModel = { text: null, done: true, target: null };
+
+  it("'Expand all' pointed at: unfold the grid first, the button named by its own label", () => {
+    expect(budgetCardModel({ target: "expandAll" }, budgetLeft)).toEqual(COLLAPSED);
+  });
+
+  it("a month cell pointed at: the sentence for a grid whose editable rows show", () => {
+    expect(budgetCardModel({ target: "cell" }, budgetLeft)).toEqual(FLAT);
+  });
+
+  it("no target (no grid on the page, no row, or not said yet): no sentence and no ring", () => {
+    expect(budgetCardModel({ target: null }, budgetLeft)).toEqual({
+      text: null,
+      done: false,
+      target: null,
+    });
+  });
+
+  it("follows the grid before the checklist is read", () => {
+    expect(budgetCardModel({ target: "expandAll" }, null)).toEqual(COLLAPSED);
+    expect(budgetCardModel({ target: "cell" }, null)).toEqual(FLAT);
+  });
+
+  it("the budget step checked: 'Done.', nothing to point at, whatever the grid shows", () => {
+    const budgeted = checklistOf({ ...upToManual, budgetEntries: 1 }, { importFolderSet: true });
+    for (const target of ["expandAll", "cell", null] as const) {
+      expect(budgetCardModel({ target }, budgeted), String(target)).toEqual(DONE);
+    }
+  });
+
+  it("a skipped step is not a checked one", () => {
+    const skipped = checklistOf(upToManual, { importFolderSet: true, skipped: ["budget"] });
+    expect(budgetCardModel({ target: "cell" }, skipped)).toEqual(FLAT);
+  });
+
+  it("reads the two sentences in French, the button named by its label", () => {
+    expect(render(COLLAPSED.text, "fr")).toBe(
+      "Cliquez Tout déplier pour afficher vos catégories, puis cliquez sur un mois et saisissez un montant. Entrée enregistre ; Tab enregistre et passe au mois suivant.",
+    );
+    expect(render(FLAT.text, "fr")).toBe(
+      "Cliquez sur un mois et saisissez un montant. Entrée enregistre ; Tab enregistre et passe au mois suivant.",
+    );
+  });
+
+  it("reads the two sentences in English, the button named by its label", () => {
+    expect(render(COLLAPSED.text, "en")).toBe(
+      "Click Expand all to show your categories, then click a month and enter an amount. Enter saves; Tab saves and moves to the next month.",
+    );
+    expect(render(FLAT.text, "en")).toBe(
+      "Click a month and enter an amount. Enter saves; Tab saves and moves to the next month.",
+    );
+  });
+});
+
 describe("onboardingTargetAttributes (#398)", () => {
   it("marks the target and its highlight when on, nothing otherwise", () => {
     expect(onboardingTargetAttributes("wizard-next", true)).toEqual({

src/utils/onboardingPath.ts

@@ -1,5 +1,7 @@
 import type { Checklist } from "./onboardingChecklist";
 import type {
+  BudgetCardInput,
+  BudgetOnboardingTargetKind,
   ChecklistItem,
   ChecklistItemKey,
   ImportCardInput,
@@ -8,7 +10,7 @@ import type {
 } from "../shared/types";
 
 /**
- * Pure rules of the guided getting-started path (#396, #398, #399).
+ * Pure rules of the guided getting-started path (#396, #398, #399, #400).
  *
  * The provider (`useOnboardingChecklist`) feeds them its state; the banner,
  * the step cards and the pages that carry a card only read what they decide.
@@ -25,10 +27,14 @@ export function nextStep(checklist: Checklist): ChecklistItem | null {
 
 /**
  * Routes whose page carries a step card. Each card issue adds its page (#398:
- * Import, #399: Transactions), and a page without a delivered card keeps the
- * banner, so a partly merged stack never removes any guidance.
+ * Import, #399: Transactions, #400: Budget), and a page without a delivered
+ * card keeps the banner, so a partly merged stack never removes any guidance.
  */
-export const CARD_PAGES: ReadonlySet<string> = new Set<string>(["/import", "/transactions"]);
+export const CARD_PAGES: ReadonlySet<string> = new Set<string>([
+  "/import",
+  "/transactions",
+  "/budget",
+]);
 
 const PAGE_STEPS: Readonly<Record<string, readonly ChecklistItemKey[]>> = {
   "/import": ["importFolder", "source", "import"],
@@ -368,6 +374,45 @@ export function transactionsCardModel(
   };
 }
 
+export interface BudgetCardModel extends StepCardModel {
+  /** The control to highlight, null for none. */
+  target: BudgetOnboardingTargetKind | null;
+}
+
+/**
+ * The Budget page's card (#400), read from the grid's target and the
+ * checklist:
+ * - the budget step checked: "Done.", nothing to point at; an entry of 0
+ *   counts, as it always has (D13);
+ * - "Expand all" pointed at: the sentence that starts by unfolding the
+ *   grid, the button named by its own label;
+ * - a month cell pointed at: the sentence for a grid whose editable rows
+ *   show;
+ * - no target (the grid is not on the page, has no row, or has not said yet):
+ *   no sentence and no ring; the title and "Skip this step" stay.
+ */
+export function budgetCardModel(
+  input: BudgetCardInput,
+  checklist: Checklist | null,
+): BudgetCardModel {
+  if (checked(checklist, "budget")) return { text: null, done: true, target: null };
+  switch (input.target) {
+    case "expandAll":
+      return {
+        text: {
+          key: "onboarding.card.budget.collapsed",
+          labels: { expand: "reports.collapse.expandAll" },
+        },
+        done: false,
+        target: "expandAll",
+      };
+    case "cell":
+      return { text: { key: "onboarding.card.budget.flat" }, done: false, target: "cell" };
+    default:
+      return { text: null, done: false, target: null };
+  }
+}
+
 /** The attributes of a highlighted control; `styles.css` draws the ring on the second one. */
 export interface OnboardingTargetAttributes {
   "data-onboarding-target"?: string;