added linear slider

server/tests/test_elevation.py

@@ -64,6 +64,34 @@ def test_build_profile_reports_unreachable(monkeypatch):
     assert "unreachable" in profile["api_error"]
 
 
+def test_resample_track_path_count_even_spacing():
+    pts = [{"lat": 55.0, "lon": 37.0}, {"lat": 55.01, "lon": 37.0}]
+    samples = elev.resample_track_path_count(pts, 50)
+    assert len(samples) == 50
+    assert samples[0]["dist_m"] == 0.0
+    assert samples[-1]["dist_m"] > samples[0]["dist_m"]
+    gaps = [samples[i]["dist_m"] - samples[i - 1]["dist_m"] for i in range(1, len(samples))]
+    assert max(gaps) - min(gaps) < 1.0
+
+
+def test_build_profile_target_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_elevations_batch",
+        lambda lats, lons: [100.0 + i for i in range(len(lats))],
+    )
+
+    profile = elev.build_elevation_profile(
+        [{"lat": 55.0, "lon": 37.0}, {"lat": 55.01, "lon": 37.0}],
+        target_points=120,
+    )
+
+    assert len(profile["points"]) == 120
+    assert profile["step_m"] > 0
+
+
 def test_find_nearest_hill_unreachable(monkeypatch):
     monkeypatch.setattr(
         elev,