test: cover group mapping, subtotals, default state, and OOB swaps

Every section maps to a group. Group order and defaults match the
spec. Budget and month subtotal calculations check out across
seeded entries. Pages render the expected details ids, income is
open by default, committed is closed. Mutations return OOB group
total spans. Sinking Funds section is visible on both pages.

Refs #11

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/quartermaster/groups.py

@@ -0,0 +1,47 @@
+from __future__ import annotations
+
+import enum
+
+from quartermaster.models import Section
+
+
+class Group(str, enum.Enum):
+    income = "income"
+    committed = "committed"
+    savings = "savings"
+    flexible = "flexible"
+
+
+GROUP_LABELS: dict[Group, str] = {
+    Group.income: "Income",
+    Group.committed: "Committed",
+    Group.savings: "Savings",
+    Group.flexible: "Flexible",
+}
+
+
+GROUP_OF_SECTION: dict[Section, Group] = {
+    Section.income: Group.income,
+    Section.fixed_bill: Group.committed,
+    Section.debt_minimum: Group.committed,
+    Section.sinking_fund: Group.savings,
+    Section.food: Group.flexible,
+    Section.subscription: Group.flexible,
+    Section.other: Group.flexible,
+}
+
+
+GROUP_DEFAULT_OPEN: dict[Group, bool] = {
+    Group.income: True,
+    Group.committed: False,
+    Group.savings: False,
+    Group.flexible: True,
+}
+
+
+def sections_in_group(group: Group) -> list[Section]:
+    return [s for s in Section if GROUP_OF_SECTION[s] == group]
+
+
+def group_order() -> list[Group]:
+    return [Group.income, Group.committed, Group.savings, Group.flexible]

src/quartermaster/models.py

@@ -24,6 +24,7 @@ class Section(str, enum.Enum):
     food = "food"
     subscription = "subscription"
     other = "other"
+    sinking_fund = "sinking_fund"
 
 
 SECTION_LABELS: dict[Section, str] = {
@@ -33,6 +34,7 @@ SECTION_LABELS: dict[Section, str] = {
     Section.food: "Food and Essentials",
     Section.subscription: "Subscriptions",
     Section.other: "Other",
+    Section.sinking_fund: "Sinking Funds",
 }
 
 

src/quartermaster/month_service.py

@@ -9,7 +9,15 @@ from enum import Enum
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
+from quartermaster.groups import (
+    GROUP_DEFAULT_OPEN,
+    GROUP_LABELS,
+    Group,
+    group_order,
+    sections_in_group,
+)
 from quartermaster.models import (
+    SECTION_LABELS,
     DebtTarget,
     Entry,
     Month,
@@ -48,6 +56,16 @@ class ZeroAmounts:
     applied: Decimal
 
 
+@dataclass(frozen=True)
+class MonthGroupView:
+    group: Group
+    label: str
+    default_open: bool
+    sections: list[MonthSectionView]
+    total_planned: Decimal
+    total_applied: Decimal
+
+
 def valid_year_month(year_month: str) -> bool:
     return bool(YEAR_MONTH_RE.match(year_month))
 
@@ -148,6 +166,28 @@ def month_zero(month: Month) -> ZeroAmounts:
     )
 
 
+def month_group_views(month: Month) -> list[MonthGroupView]:
+    views: list[MonthGroupView] = []
+    for group in group_order():
+        sections = [
+            section_view(month, s, SECTION_LABELS[s])
+            for s in sections_in_group(group)
+        ]
+        planned = sum((sv.total_planned for sv in sections), Decimal("0"))
+        applied = sum((sv.total_applied for sv in sections), Decimal("0"))
+        views.append(
+            MonthGroupView(
+                group=group,
+                label=GROUP_LABELS[group],
+                default_open=GROUP_DEFAULT_OPEN[group],
+                sections=sections,
+                total_planned=planned,
+                total_applied=applied,
+            )
+        )
+    return views
+
+
 def section_view(month: Month, section: Section, label: str) -> MonthSectionView:
     entries = [e for e in month.entries if e.section == section]
     entries.sort(key=lambda e: e.id)

src/quartermaster/routes.py

@@ -66,6 +66,14 @@ def _render_zero(request: Request, db: Session) -> HTMLResponse:
     )
 
 
+def _render_group_totals(request: Request, db: Session) -> HTMLResponse:
+    return templates.TemplateResponse(
+        request,
+        "partials/budget_group_totals.html",
+        {"groups": service.budget_group_views(db)},
+    )
+
+
 def _append_oob(base: HTMLResponse, *extras: HTMLResponse) -> HTMLResponse:
     body = base.body.decode() + "".join(e.body.decode() for e in extras)
     return HTMLResponse(body)
@@ -73,7 +81,7 @@ def _append_oob(base: HTMLResponse, *extras: HTMLResponse) -> HTMLResponse:
 
 @router.get("/", response_class=HTMLResponse)
 def index(request: Request, db: Session = Depends(get_session)) -> HTMLResponse:
-    sections = [_section_view(db, s) for s in Section]
+    groups = service.budget_group_views(db)
     target = service.get_debt_target(db)
     debt_minimums = service.list_entries(db, Section.debt_minimum)
     current_ym = month_service.current_year_month()
@@ -82,7 +90,7 @@ def index(request: Request, db: Session = Depends(get_session)) -> HTMLResponse:
         request,
         "index.html",
         {
-            "sections": sections,
+            "groups": groups,
             "target": target,
             "debt_minimums": debt_minimums,
             "current_year_month": current_ym,
@@ -107,7 +115,10 @@ def create_entry(
     parsed = _parse_amount(amount)
     service.add_entry(db, section, clean_name, parsed)
     response = _render_section(request, db, section)
-    extras: list[HTMLResponse] = [_render_zero(request, db)]
+    extras: list[HTMLResponse] = [
+        _render_zero(request, db),
+        _render_group_totals(request, db),
+    ]
     if section == Section.debt_minimum:
         extras.append(_render_target(request, db))
     return _append_oob(response, *extras)
@@ -123,7 +134,10 @@ def remove_entry(
     if entry is None:
         raise HTTPException(status_code=404, detail="entry not found")
     response = _render_section(request, db, entry.section)
-    extras: list[HTMLResponse] = [_render_zero(request, db)]
+    extras: list[HTMLResponse] = [
+        _render_zero(request, db),
+        _render_group_totals(request, db),
+    ]
     if entry.section == Section.debt_minimum:
         extras.append(_render_target(request, db))
     return _append_oob(response, *extras)

src/quartermaster/routes_month.py

@@ -83,6 +83,14 @@ def _render_zero(request: Request, month: Month) -> HTMLResponse:
     )
 
 
+def _render_group_totals(request: Request, month: Month) -> HTMLResponse:
+    return templates.TemplateResponse(
+        request,
+        "partials/month_group_totals.html",
+        {"groups": month_service.month_group_views(month)},
+    )
+
+
 def _append_oob(base: HTMLResponse, *extras: HTMLResponse) -> HTMLResponse:
     body = base.body.decode() + "".join(e.body.decode() for e in extras)
     return HTMLResponse(body)
@@ -120,7 +128,7 @@ def view_month(
             "prev_year_month": prev_ym,
             "next_year_month": next_ym,
             "all_months": all_months,
-            "sections": _section_views(month),
+            "groups": month_service.month_group_views(month),
             "target": month_service.get_month_target(db, month),
             "debt_minimums": sorted(
                 (e for e in month.entries if e.section == Section.debt_minimum),
@@ -169,6 +177,7 @@ def add_month_entry(
     return _append_oob(
         _render_section(request, month, section),
         _render_zero(request, month),
+        _render_group_totals(request, month),
     )
 
 
@@ -184,7 +193,10 @@ def delete_month_entry(
     if section is None:
         raise HTTPException(status_code=404, detail="entry not found")
     db.refresh(month)
-    extras: list[HTMLResponse] = [_render_zero(request, month)]
+    extras: list[HTMLResponse] = [
+        _render_zero(request, month),
+        _render_group_totals(request, month),
+    ]
     if section == Section.debt_minimum:
         extras.append(_render_target(request, db, month))
     return _append_oob(_render_section(request, month, section), *extras)
@@ -222,6 +234,7 @@ def update_month_entry(
     return _append_oob(
         _render_section(request, month, updated.section),
         _render_zero(request, month),
+        _render_group_totals(request, month),
     )
 
 

src/quartermaster/service.py

@@ -6,7 +6,14 @@ from decimal import Decimal
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
-from quartermaster.models import DebtTarget, Entry, Section
+from quartermaster.groups import (
+    GROUP_DEFAULT_OPEN,
+    GROUP_LABELS,
+    Group,
+    group_order,
+    sections_in_group,
+)
+from quartermaster.models import SECTION_LABELS, DebtTarget, Entry, Section
 
 
 def zero_tone(value: Decimal) -> str:
@@ -23,6 +30,15 @@ class SectionView:
     total: Decimal
 
 
+@dataclass(frozen=True)
+class BudgetGroupView:
+    group: Group
+    label: str
+    default_open: bool
+    sections: list[SectionView]
+    total: Decimal
+
+
 def list_entries(db: Session, section: Section) -> list[Entry]:
     stmt = select(Entry).where(Entry.section == section).order_by(Entry.id)
     return list(db.scalars(stmt))
@@ -32,6 +48,33 @@ def section_total(entries: list[Entry]) -> Decimal:
     return sum((e.amount for e in entries), Decimal("0"))
 
 
+def section_view(db: Session, section: Section) -> SectionView:
+    entries = list_entries(db, section)
+    return SectionView(
+        section=section,
+        label=SECTION_LABELS[section],
+        entries=entries,
+        total=section_total(entries),
+    )
+
+
+def budget_group_views(db: Session) -> list[BudgetGroupView]:
+    views: list[BudgetGroupView] = []
+    for group in group_order():
+        sections = [section_view(db, s) for s in sections_in_group(group)]
+        total = sum((sv.total for sv in sections), Decimal("0"))
+        views.append(
+            BudgetGroupView(
+                group=group,
+                label=GROUP_LABELS[group],
+                default_open=GROUP_DEFAULT_OPEN[group],
+                sections=sections,
+                total=total,
+            )
+        )
+    return views
+
+
 def budget_zero(db: Session) -> Decimal:
     stmt = select(Entry)
     total_income = Decimal("0")

src/quartermaster/static/app.css

@@ -157,6 +157,70 @@ button[type=submit] {
   border-bottom-style: dashed;
 }
 
+/* Section groups --------------------------------------------------------- */
+
+details.group {
+  margin-top: 1rem;
+  border-top: 2px solid var(--ink);
+}
+
+details.group:last-of-type {
+  border-bottom: 2px solid var(--ink);
+}
+
+details.group > summary {
+  display: flex;
+  align-items: baseline;
+  gap: 0.5rem;
+  padding: 0.6rem 0.5rem;
+  cursor: pointer;
+  list-style: none;
+  user-select: none;
+}
+
+details.group > summary::-webkit-details-marker { display: none; }
+
+details.group > summary .chevron {
+  display: inline-block;
+  width: 0.8rem;
+  transition: transform 0.12s ease-out;
+  color: var(--muted);
+}
+
+details.group > summary .chevron::before {
+  content: "\25B6"; /* black right-pointing triangle */
+  font-size: 0.7rem;
+}
+
+details.group[open] > summary .chevron {
+  transform: rotate(90deg);
+}
+
+details.group > summary .group-name {
+  flex: 1;
+  font-size: 1.05rem;
+  font-weight: 700;
+  text-transform: uppercase;
+  letter-spacing: 0.08em;
+}
+
+details.group > summary .group-total {
+  font-variant-numeric: tabular-nums;
+  font-weight: 700;
+  color: var(--accent);
+  font-size: 1.05rem;
+}
+
+details.group > .section {
+  margin-top: 0.5rem;
+  margin-bottom: 1rem;
+  padding-left: 1rem;
+}
+
+details.group > .section:last-child {
+  margin-bottom: 0.75rem;
+}
+
 /* Zero Amount widget ----------------------------------------------------- */
 
 :root {

src/quartermaster/templates/index.html

@@ -19,13 +19,20 @@
     {% endif %}
   </nav>
   {% include "partials/budget_zero.html" %}
-  {% for section in sections %}
-    {% if section.section.value == 'debt_minimum' %}
+  {% for g in groups %}
+    <details class="group" id="group-{{ g.group.value }}"{% if g.default_open %} open{% endif %}>
+      <summary class="group-header">
+        <span class="chevron" aria-hidden="true"></span>
+        <span class="group-name">{{ g.label }}</span>
+        <span class="group-total" id="group-total-{{ g.group.value }}">${{ '%.2f' | format(g.total) }}</span>
+      </summary>
+      {% for section in g.sections %}
         {% include "partials/section.html" %}
+        {% if g.group.value == 'committed' and section.section.value == 'debt_minimum' %}
           {% include "partials/target_card.html" %}
-    {% else %}
-      {% include "partials/section.html" %}
         {% endif %}
       {% endfor %}
+    </details>
+  {% endfor %}
 </div>
 {% endblock %}

src/quartermaster/templates/month.html

@@ -3,13 +3,24 @@
 <div class="budget">
   {% include "partials/month_nav.html" %}
   {% include "partials/month_zero.html" %}
-  {% for section in sections %}
-    {% if section.section.value == 'debt_minimum' %}
+  {% for g in groups %}
+    <details class="group" id="group-{{ g.group.value }}"{% if g.default_open %} open{% endif %}>
+      <summary class="group-header">
+        <span class="chevron" aria-hidden="true"></span>
+        <span class="group-name">{{ g.label }}</span>
+        <span class="group-total" id="group-total-{{ g.group.value }}">
+          <span class="applied">${{ '%.2f' | format(g.total_applied) }}</span>
+          <span class="divider">/</span>
+          <span class="planned">${{ '%.2f' | format(g.total_planned) }}</span>
+        </span>
+      </summary>
+      {% for section in g.sections %}
         {% include "partials/month_section.html" %}
+        {% if g.group.value == 'committed' and section.section.value == 'debt_minimum' %}
           {% include "partials/month_target.html" %}
-    {% else %}
-      {% include "partials/month_section.html" %}
         {% endif %}
       {% endfor %}
+    </details>
+  {% endfor %}
 </div>
 {% endblock %}

src/quartermaster/templates/partials/budget_group_totals.html

@@ -0,0 +1,3 @@
+{% for g in groups -%}
+<span class="group-total" id="group-total-{{ g.group.value }}" hx-swap-oob="outerHTML">${{ '%.2f' | format(g.total) }}</span>
+{% endfor -%}

src/quartermaster/templates/partials/month_group_totals.html

@@ -0,0 +1,7 @@
+{% for g in groups -%}
+<span class="group-total" id="group-total-{{ g.group.value }}" hx-swap-oob="outerHTML">
+  <span class="applied">${{ '%.2f' | format(g.total_applied) }}</span>
+  <span class="divider">/</span>
+  <span class="planned">${{ '%.2f' | format(g.total_planned) }}</span>
+</span>
+{% endfor -%}

tests/test_groups.py

@@ -0,0 +1,164 @@
+from __future__ import annotations
+
+from decimal import Decimal
+
+from quartermaster import month_service, service
+from quartermaster.groups import (
+    GROUP_DEFAULT_OPEN,
+    GROUP_OF_SECTION,
+    Group,
+    group_order,
+    sections_in_group,
+)
+from quartermaster.models import Section
+
+
+def test_every_section_maps_to_a_group():
+    for s in Section:
+        assert s in GROUP_OF_SECTION, f"{s} is not assigned to a group"
+
+
+def test_group_order_is_stable():
+    assert group_order() == [
+        Group.income,
+        Group.committed,
+        Group.savings,
+        Group.flexible,
+    ]
+
+
+def test_sinking_fund_is_in_savings_group():
+    assert GROUP_OF_SECTION[Section.sinking_fund] == Group.savings
+    assert Section.sinking_fund in sections_in_group(Group.savings)
+
+
+def test_defaults_match_spec():
+    assert GROUP_DEFAULT_OPEN[Group.income] is True
+    assert GROUP_DEFAULT_OPEN[Group.committed] is False
+    assert GROUP_DEFAULT_OPEN[Group.savings] is False
+    assert GROUP_DEFAULT_OPEN[Group.flexible] is True
+
+
+def test_committed_group_contains_fixed_and_debt_minimum():
+    committed_sections = sections_in_group(Group.committed)
+    assert Section.fixed_bill in committed_sections
+    assert Section.debt_minimum in committed_sections
+    # debt_target is a pointer, not a section; not part of the enum
+    assert len(committed_sections) == 2
+
+
+def test_budget_group_views_totals(db):
+    service.add_entry(db, Section.income, "Paycheck", Decimal("2500.00"))
+    service.add_entry(db, Section.fixed_bill, "Rent", Decimal("1200.00"))
+    service.add_entry(db, Section.debt_minimum, "Card A", Decimal("40.00"))
+    service.add_entry(db, Section.sinking_fund, "Emergency", Decimal("300.00"))
+    service.add_entry(db, Section.food, "Groceries", Decimal("500.00"))
+    views = {v.group: v for v in service.budget_group_views(db)}
+    assert views[Group.income].total == Decimal("2500.00")
+    assert views[Group.committed].total == Decimal("1240.00")
+    assert views[Group.savings].total == Decimal("300.00")
+    assert views[Group.flexible].total == Decimal("500.00")
+
+
+def test_month_group_views_planned_and_applied(db):
+    service.add_entry(db, Section.income, "Paycheck", Decimal("2500.00"))
+    service.add_entry(db, Section.fixed_bill, "Rent", Decimal("1200.00"))
+    service.add_entry(db, Section.sinking_fund, "Emergency", Decimal("300.00"))
+    month = month_service.create_month(db, "2026-04")
+    # seed applied values
+    rent = next(e for e in month.entries if e.origin_name == "Rent")
+    month_service.update_month_entry(
+        db, month, rent.id, applied=Decimal("1200.00")
+    )
+    db.refresh(month)
+    views = {v.group: v for v in month_service.month_group_views(month)}
+    assert views[Group.income].total_planned == Decimal("2500.00")
+    assert views[Group.income].total_applied == Decimal("0.00")
+    assert views[Group.committed].total_planned == Decimal("1200.00")
+    assert views[Group.committed].total_applied == Decimal("1200.00")
+    assert views[Group.savings].total_planned == Decimal("300.00")
+    assert views[Group.savings].total_applied == Decimal("0.00")
+    assert views[Group.flexible].total_planned == Decimal("0.00")
+
+
+def test_budget_page_renders_details_groups(client):
+    response = client.get("/")
+    assert response.status_code == 200
+    # four <details class="group"> blocks
+    assert response.text.count('class="group"') >= 4
+    # default open state: income and flexible open, committed and savings closed
+    assert 'id="group-income"' in response.text
+    assert 'id="group-committed"' in response.text
+    assert 'id="group-savings"' in response.text
+    assert 'id="group-flexible"' in response.text
+    # income has " open" in its details tag; committed does not
+    income_tag_start = response.text.index('id="group-income"')
+    income_chunk = response.text[income_tag_start - 80 : income_tag_start + 80]
+    assert " open" in income_chunk
+    committed_tag_start = response.text.index('id="group-committed"')
+    committed_chunk = response.text[
+        committed_tag_start - 80 : committed_tag_start + 80
+    ]
+    assert " open" not in committed_chunk
+
+
+def test_add_entry_returns_group_total_oob(client):
+    response = client.post(
+        "/sections/income/entries",
+        data={"name": "Paycheck", "amount": "2500.00"},
+    )
+    assert response.status_code == 200
+    assert 'id="group-total-income"' in response.text
+    assert 'hx-swap-oob="outerHTML"' in response.text
+
+
+def test_sinking_fund_entry_ends_up_in_savings_group_total(client):
+    response = client.post(
+        "/sections/sinking_fund/entries",
+        data={"name": "Emergency", "amount": "500.00"},
+    )
+    assert response.status_code == 200
+    # OOB response contains group-total-savings with 500
+    assert 'id="group-total-savings"' in response.text
+    assert "$500.00" in response.text
+
+
+def test_month_page_renders_group_headers_with_paired_totals(client):
+    client.post(
+        "/sections/income/entries",
+        data={"name": "Paycheck", "amount": "2500.00"},
+    )
+    client.post("/month/2026-04/create")
+    response = client.get("/month/2026-04")
+    assert response.status_code == 200
+    assert 'id="group-committed"' in response.text
+    assert 'id="group-total-income"' in response.text
+
+
+def test_month_mutation_returns_group_total_oob(client):
+    client.post(
+        "/sections/income/entries",
+        data={"name": "Paycheck", "amount": "2500.00"},
+    )
+    client.post("/month/2026-04/create")
+    response = client.post(
+        "/month/2026-04/entries/1", data={"applied": "2500.00"}
+    )
+    assert response.status_code == 200
+    assert 'id="group-total-income"' in response.text
+
+
+def test_sinking_fund_section_shows_on_budget_page(client):
+    response = client.get("/")
+    assert "Sinking Funds" in response.text
+
+
+def test_sinking_fund_section_shows_on_month_page(client):
+    client.post(
+        "/sections/sinking_fund/entries",
+        data={"name": "Emergency", "amount": "500.00"},
+    )
+    client.post("/month/2026-04/create")
+    response = client.get("/month/2026-04")
+    assert "Sinking Funds" in response.text
+    assert "Emergency" in response.text