added subprox

server/tests/test_elevation.py

@@ -93,3 +93,36 @@ def test_find_nearest_hill_picks_nearest_peak(monkeypatch):
     result = elev.find_nearest_hill(55.75, 37.62, radius_m=2000, step_m=300, min_prominence_m=8)
     assert result["ok"] is True
     assert result["hill"]["elevation_m"] >= 120.0
+
+
+def test_build_elevation_grid_delta(monkeypatch):
+    monkeypatch.setattr(elev, "_probe_checked_at", 0.0)
+    monkeypatch.setattr(elev, "probe_elevation_api", lambda force=False: {"ok": True, "error": None})
+
+    def fake_batch(lats, lons):
+        return [100.0 + (la - 55.75) * 1000.0 for la, lo in zip(lats, lons)]
+
+    monkeypatch.setattr(elev, "fetch_elevation_m", lambda lat, lon: 100.0)
+    monkeypatch.setattr(elev, "fetch_elevations_batch", fake_batch)
+
+    result = elev.build_elevation_grid(55.75, 37.62, radius_m=100, step_m=10)
+    assert result["ok"] is True
+    assert result["step_m"] == 10
+    assert len(result["points"]) > 0
+    assert result["min_delta_m"] <= 0 <= result["max_delta_m"]
+    assert all("delta_m" in p for p in result["points"])
+
+
+def test_build_elevation_grid_limits_points(monkeypatch):
+    monkeypatch.setattr(elev, "_probe_checked_at", 0.0)
+    monkeypatch.setattr(elev, "probe_elevation_api", lambda force=False: {"ok": True, "error": None})
+    monkeypatch.setattr(elev, "fetch_elevation_m", lambda lat, lon: 50.0)
+    monkeypatch.setattr(
+        elev,
+        "fetch_elevations_batch",
+        lambda lats, lons: [50.0] * len(lats),
+    )
+
+    step = elev._resolve_grid_step(55.75, 37.62, 500.0, 5.0)
+    cells = elev._sample_circular_grid(55.75, 37.62, 500.0, step)
+    assert len(cells) <= elev._MAX_GRID_POINTS