From 56f607b55fc37b4e7b99311071d89c10e9eb0d73 Mon Sep 17 00:00:00 2001
From: Sam Deans <sdeans0@protonmail.com>
Date: Tue, 15 Apr 2025 19:41:12 +0100
Subject: [PATCH] feat: allow optional altitude

---
 pydantic_geojson/_base.py              | 23 ++++++++++++--
 tests/test_coordinates.py              | 44 ++++++++++++++++++++++++++
 tests/test_feature_on_lat_lon_limit.py |  2 +-
 tests/test_line_string.py              |  2 +-
 4 files changed, 67 insertions(+), 4 deletions(-)
 create mode 100644 tests/test_coordinates.py

diff --git a/pydantic_geojson/_base.py b/pydantic_geojson/_base.py
index 8c7f957..32f58a2 100644
--- a/pydantic_geojson/_base.py
+++ b/pydantic_geojson/_base.py
@@ -34,6 +34,13 @@
     ),
 ]
 
+AltField = Annotated[
+    Union[float, int],
+    Field(
+        title="Coordinate altitude",
+    ),
+]
+
 PointFieldType = Annotated[Literal[POINT], Field(POINT, title="Point")]  # type: ignore
 
 MultiPointFieldType = Annotated[
@@ -104,10 +111,22 @@
 class Coordinates(NamedTuple):
     lon: LonField
     lat: LatField
+    alt: Optional[AltField] = None
 
     def __eq__(self, other):
-        # Note that +180 and -180 are not considered equal here
-        return math.isclose(self.lon, other.lon) and math.isclose(self.lat, other.lat)
+        # Note that +180 and -180 are not considered equal latitude here
+        lon_equal = math.isclose(self.lon, other.lon)
+        lat_equal = math.isclose(self.lat, other.lat)
+        alt_equal = (
+            self.alt is None
+            and other.alt is None
+            or (
+                self.alt is not None
+                and other.alt is not None
+                and math.isclose(self.alt, other.alt)
+            )
+        )
+        return lon_equal and lat_equal and alt_equal
 
 
 def check_linear_ring(linear_ring: List[Coordinates]) -> List[Coordinates]:
diff --git a/tests/test_coordinates.py b/tests/test_coordinates.py
new file mode 100644
index 0000000..961a395
--- /dev/null
+++ b/tests/test_coordinates.py
@@ -0,0 +1,44 @@
+import pytest
+from pydantic_geojson._base import Coordinates
+
+
+@pytest.mark.parametrize(
+    "coord_one,coord_two,is_equal",
+    [
+        (
+            Coordinates(0, 0, None),
+            Coordinates(0, 0, None),
+            True,
+        ),  # None and None are equivalent
+        (
+            Coordinates(0, 0, 0),
+            Coordinates(0, 0, 0),
+            True,
+        ),  # Zero and Zero are equivalent
+        (
+            Coordinates(0, 0, None),
+            Coordinates(0, 0, 0),
+            False,
+        ),  # Altiture not specified for coord_one
+        (Coordinates(1, 0, None), Coordinates(0, 0, None), False),  # Latitude not equal
+        (
+            Coordinates(0, 1, None),
+            Coordinates(0, 0, None),
+            False,
+        ),  # Longitude not equal
+        (
+            Coordinates(0, 0, 1),
+            Coordinates(0, 0, 0),
+            False,
+        ),  # Altitude specified but not equal
+        (
+            Coordinates(180, 0, None),
+            Coordinates(-180, 0, None),
+            False,
+        ),  # Plus and minus 180 latitude are not considered equal
+    ],
+)
+def test_coordinate_equality(coord_one, coord_two, is_equal):
+    assert (
+        coord_one == coord_two
+    ) == is_equal, f"Result of {coord_one} == {coord_two} should be {is_equal}"
diff --git a/tests/test_feature_on_lat_lon_limit.py b/tests/test_feature_on_lat_lon_limit.py
index 7a50500..d8daa39 100644
--- a/tests/test_feature_on_lat_lon_limit.py
+++ b/tests/test_feature_on_lat_lon_limit.py
@@ -33,7 +33,7 @@ def test_loads_model_linestring(self):
         coordinates = ls_model.coordinates
 
         for lsi_key, ls_item in enumerate(coordinates):
-            lon, lat = ls_item
+            lon, lat, _ = ls_item
             assert data_linestring["coordinates"][lsi_key] == [lon, lat]
 
         assert ls_model.type == data_linestring["type"]
diff --git a/tests/test_line_string.py b/tests/test_line_string.py
index 3e0257c..af7823d 100644
--- a/tests/test_line_string.py
+++ b/tests/test_line_string.py
@@ -33,7 +33,7 @@ def test_loads_model(self, valid_linestring_data):
         coordinates = ls_model.coordinates
 
         for lsi_key, ls_item in enumerate(coordinates):
-            lon, lat = ls_item
+            lon, lat, _ = ls_item
             assert valid_linestring_data["coordinates"][lsi_key] == [lon, lat]
 
         assert ls_model.type == valid_linestring_data["type"]