fix(parser): always return altitude as a float

A coordinate declaring an altitude produced a float, one omitting it
produced the integer 0, so the type of the same key depended on the
input. The array shape documented on parsePointCoordinates() claims
float in both cases, and PHPStan believed it.

Callers comparing strictly, or encoding to JSON and diffing the result,
saw 0 where they had been told to expect 0.0.

Author: danielebarbaro

src/Traits/ParsesCoordinates.php

@@ -16,7 +16,7 @@ protected function parsePointCoordinates(string $coordinates): array
         return [
             'longitude' => (float) $parts[0],
             'latitude' => (float) ($parts[1] ?? 0),
-            'altitude' => isset($parts[2]) ? (float) $parts[2] : 0,
+            'altitude' => isset($parts[2]) ? (float) $parts[2] : 0.0,
         ];
     }
 
@@ -35,7 +35,7 @@ protected function parseLineStringCoordinates(string $coordinates): array
                 $coords[] = [
                     'longitude' => (float) $parts[0],
                     'latitude' => (float) $parts[1],
-                    'altitude' => isset($parts[2]) ? (float) $parts[2] : 0,
+                    'altitude' => isset($parts[2]) ? (float) $parts[2] : 0.0,
                 ];
             }
         }

tests/AltitudeTest.php

@@ -0,0 +1,47 @@
+<?php
+
+use PlinCode\KmlParser\KmlParser;
+
+function kmlWithCoordinates(string $coordinates): string
+{
+    return <<<XML
+<?xml version="1.0" encoding="UTF-8"?>
+<kml xmlns="http://www.opengis.net/kml/2.2">
+    <Document>
+        <Placemark>
+            <Point>
+                <coordinates>{$coordinates}</coordinates>
+            </Point>
+        </Placemark>
+        <Placemark>
+            <LineString>
+                <coordinates>{$coordinates} 7.9,45.9</coordinates>
+            </LineString>
+        </Placemark>
+    </Document>
+</kml>
+XML;
+}
+
+it('returns a float altitude when the coordinate omits it', function () {
+    $placemarks = (new KmlParser)->loadFromString(kmlWithCoordinates('7.7,45.8'))->getPlacemarks();
+
+    expect($placemarks[0]['coordinates']['altitude'])->toBeFloat()
+        ->and($placemarks[1]['coordinates'][0]['altitude'])->toBeFloat()
+        ->and($placemarks[1]['coordinates'][1]['altitude'])->toBeFloat();
+});
+
+it('returns a float altitude when the coordinate declares it', function () {
+    $placemark = (new KmlParser)->loadFromString(kmlWithCoordinates('7.7,45.8,12'))->getPlacemarks()[0];
+
+    expect($placemark['coordinates']['altitude'])->toBeFloat()
+        ->and($placemark['coordinates']['altitude'])->toBe(12.0);
+});
+
+it('keeps the altitude a float through to GeoJSON', function () {
+    $geometry = (new KmlParser)->loadFromString(kmlWithCoordinates('7.7,45.8'))
+        ->toGeoJson()['features'][0]['geometry'];
+
+    expect($geometry['coordinates'][2])->toBeFloat()
+        ->and($geometry['coordinates'])->toBe([7.7, 45.8, 0.0]);
+});