feat(v1.5.0): Relations, Rollups, Formulas — FormulaEngine, RollupEngine, API

- FormulaEngine: 19 functions (prop, if, concat, round, now, today, dateAdd, replace, ...)
- RollupEngine: 12 aggregations (count, sum, avg, min, max, range, unique, percent_checked)
- API relation: POST /db/{id}/properties/relation + /link (bidirectional)
- API rollup: POST /db/rollup/compute
- API formula: POST /db/formula/evaluate
- FKs fix: related_collection_id/relation_property_id/target_property_id → ON DELETE SET NULL
- 43/43 tests passent (+5 tests v1.5)
- Version 1.4.0 → 1.5.0
- Docs: ROADMAP, CHANGELOG à jour

tests/test_app.py

@@ -34,7 +34,7 @@ def test_health(client):
     data = resp.json()
     assert "status" in data
     assert data["db"] is True
-    assert data["version"] == "1.4.0"
+    assert data["version"] == "1.5.0"
 
 
 def test_dashboard(client):
@@ -191,7 +191,7 @@ def test_csrf_protects_sync(client):
 
 def test_version_in_health(client):
     resp = client.get("/api/health")
-    assert resp.json()["version"] == "1.4.0"
+    assert resp.json()["version"] == "1.5.0"
 
 
 def test_db_tables_exist(client):
@@ -359,7 +359,7 @@ def test_boards_as_collections(client):
     assert isinstance(data["boards"], list)
 
 
-# ── v1.4.0: Collection Properties ──
+# ── v1.5.0: Collection Properties ──
 
 def test_property_types_api(client):
     """GET /db/property-types/api — should list available types."""
@@ -467,3 +467,141 @@ def test_collection_properties_validation(client):
     assert resp.status_code == 400
 
     client.delete(f"/db/api/{coll_id}")
+
+
+# ── v1.5.0: Relations, Rollups, Formulas ──
+
+def test_create_relation_property(client):
+    """Create a relation property between two collections."""
+    r1 = client.post("/db/api", json={"name": "Projects"})
+    r2 = client.post("/db/api", json={"name": "Tasks"})
+    c1, c2 = r1.json()["id"], r2.json()["id"]
+
+    resp = client.post(f"/db/{c1}/properties/relation", json={
+        "name": "Tasks", "related_collection_id": c2, "reverse_name": "Project",
+    })
+    assert resp.status_code == 200
+    assert resp.json()["prop_type"] == "relation"
+
+    resp2 = client.get(f"/db/{c2}/properties/api")
+    names = [p["name"] for p in resp2.json()["properties"]]
+    assert "Project" in names
+
+    client.delete(f"/db/api/{c2}")  # c2 first (has reverse FK → c1)
+    client.delete(f"/db/api/{c1}")
+
+
+def test_link_pages_via_relation(client):
+    """Link two pages via a relation and verify reverse."""
+    r1 = client.post("/db/api", json={"name": "A"})
+    r2 = client.post("/db/api", json={"name": "B"})
+    c1, c2 = r1.json()["id"], r2.json()["id"]
+
+    rel = client.post(f"/db/{c1}/properties/relation", json={
+        "name": "Items", "related_collection_id": c2, "reverse_name": "Parent",
+    })
+    prop_id = rel.json()["id"]
+
+    p1 = client.post(f"/db/{c1}/pages/api", json={"title": "Page A"})
+    p2 = client.post(f"/db/{c2}/pages/api", json={"title": "Page B"})
+    pid1, pid2 = p1.json()["id"], p2.json()["id"]
+
+    resp = client.post(f"/db/{c1}/properties/relation/link", json={
+        "property_id": prop_id, "source_page_id": pid1, "target_page_id": pid2,
+    })
+    assert resp.status_code == 200
+
+    src = client.get(f"/db/pages/{pid1}/api").json()
+    props = json.loads(src["property_values_json"])
+    assert pid2 in props.get(str(prop_id), [])
+
+    tgt = client.get(f"/db/pages/{pid2}/api").json()
+    tprops = json.loads(tgt["property_values_json"])
+    assert any(pid1 in (v if isinstance(v, list) else []) for v in tprops.values())
+
+    client.delete(f"/db/api/{c2}")  # c2 first
+    client.delete(f"/db/api/{c1}")
+
+
+def test_rollup_compute(client):
+    """Compute rollup aggregation via relation."""
+    r1 = client.post("/db/api", json={"name": "Proj"})
+    r2 = client.post("/db/api", json={"name": "Task"})
+    c1, c2 = r1.json()["id"], r2.json()["id"]
+
+    rel = client.post(f"/db/{c1}/properties/relation", json={
+        "name": "TaskList", "related_collection_id": c2, "reverse_name": "ParentProj",
+    })
+    rel_id = rel.json()["id"]
+
+    num = client.post(f"/db/{c2}/properties/api", json={"name": "Hours", "prop_type": "number"})
+    num_id = num.json()["id"]
+
+    proj = client.post(f"/db/{c1}/pages/api", json={"title": "Proj1"})
+    pid = proj.json()["id"]
+
+    t1 = client.post(f"/db/{c2}/pages/api", json={"title": "Task 1", "properties": {str(num_id): 5}})
+    t2 = client.post(f"/db/{c2}/pages/api", json={"title": "Task 2", "properties": {str(num_id): 10}})
+
+    client.post(f"/db/{c1}/properties/relation/link", json={
+        "property_id": rel_id, "source_page_id": pid, "target_page_id": t1.json()["id"],
+    })
+    client.post(f"/db/{c1}/properties/relation/link", json={
+        "property_id": rel_id, "source_page_id": pid, "target_page_id": t2.json()["id"],
+    })
+
+    resp = client.post("/db/rollup/compute", json={
+        "collection_id": c1, "relation_property_id": rel_id,
+        "target_property_id": num_id, "page_id": pid, "function": "sum",
+    })
+    assert resp.status_code == 200
+    assert resp.json()["result"] == 15.0
+
+    resp2 = client.post("/db/rollup/compute", json={
+        "collection_id": c1, "relation_property_id": rel_id,
+        "target_property_id": num_id, "page_id": pid, "function": "count",
+    })
+    assert resp2.json()["result"] == 2
+
+    client.delete(f"/db/api/{c2}")  # c2 first
+    client.delete(f"/db/api/{c1}")
+
+
+def test_formula_evaluate(client):
+    """Evaluate formula expressions."""
+    # Function-based expressions work
+    resp = client.post("/db/formula/evaluate", json={
+        "expression": "round(3.14159, 2)", "context": {},
+    })
+    assert resp.status_code == 200
+    assert resp.json()["result"] == 3.14
+
+    resp = client.post("/db/formula/evaluate", json={
+        "expression": "if(prop('Done'), 'OK', 'Pending')",
+        "context": {"Done": True},
+    })
+    assert resp.json()["result"] == "OK"
+
+    resp = client.post("/db/formula/evaluate", json={
+        "expression": "concat(prop('First'), ' ', prop('Last'))",
+        "context": {"First": "John", "Last": "Doe"},
+    })
+    assert resp.json()["result"] == "John Doe"
+
+    resp = client.post("/db/formula/evaluate", json={
+        "expression": "length(prop('Text'))",
+        "context": {"Text": "Hello"},
+    })
+    assert resp.json()["result"] == 5
+
+    resp = client.post("/db/formula/evaluate", json={
+        "expression": "toNumber('42')",
+        "context": {},
+    })
+    assert resp.json()["result"] == 42.0
+
+
+def test_formula_empty_expression(client):
+    """Empty expression should return 400."""
+    resp = client.post("/db/formula/evaluate", json={"expression": "", "context": {}})
+    assert resp.status_code == 400