From c0632d2f8a8c7ac4071f1590d2bbd307410bf5cf Mon Sep 17 00:00:00 2001
From: Anshul Singhvi <anshulsinghvi@gmail.com>
Date: Fri, 16 Jan 2026 06:52:10 -0500
Subject: [PATCH] Add tests for GeoInterface.coordtype and fix method ambiguity

Add comprehensive tests for coordtype covering Point, Line, LineString,
Polygon, MultiPoint, MultiLineString, MultiPolygon, Triangle, and Mesh
types with different coordinate types (Int, Float32, Float64).

Fix method ambiguity in coordtype implementation by using specific
GeoInterface traits instead of AbstractGeometryTrait, avoiding conflicts
with GeoInterface's fallback methods.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 ext/GeometryBasicsGeoInterfaceExt.jl | 26 +++++++++++--
 test/geointerface.jl                 | 58 ++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+), 4 deletions(-)

diff --git a/ext/GeometryBasicsGeoInterfaceExt.jl b/ext/GeometryBasicsGeoInterfaceExt.jl
index 8464acd3..48cbcca7 100644
--- a/ext/GeometryBasicsGeoInterfaceExt.jl
+++ b/ext/GeometryBasicsGeoInterfaceExt.jl
@@ -160,11 +160,29 @@ function _collect_with_type(::Type{PT}, geom) where {PT <: Point{2}}
 end
 
 # coordtype implementation - GeometryBasics encodes coordinate type in eltype
+# Use specific traits to avoid method ambiguity with GeoInterface fallbacks
 if isdefined(GeoInterface, :coordtype)
-    # For types with coordinate type T as a type parameter
-    GeoInterface.coordtype(::GeoInterface.AbstractGeometryTrait, geom::Point{Dim,T}) where {Dim,T} = T
-    GeoInterface.coordtype(::GeoInterface.AbstractGeometryTrait, geom::AbstractGeometry{Dim,T}) where {Dim,T} = T
-    GeoInterface.coordtype(::GeoInterface.AbstractGeometryTrait, geom::Simplex{Dim,T,N}) where {Dim,T,N} = T
+    # Point
+    GeoInterface.coordtype(::GeoInterface.PointTrait, geom::Point{Dim,T}) where {Dim,T} = T
+    # Line
+    GeoInterface.coordtype(::GeoInterface.LineTrait, geom::Line{Dim,T}) where {Dim,T} = T
+    # LineString
+    GeoInterface.coordtype(::GeoInterface.LineStringTrait, geom::LineString{Dim,T}) where {Dim,T} = T
+    # Polygon
+    GeoInterface.coordtype(::GeoInterface.PolygonTrait, geom::Polygon{Dim,T}) where {Dim,T} = T
+    # MultiPoint
+    GeoInterface.coordtype(::GeoInterface.MultiPointTrait, geom::MultiPoint{Dim,T}) where {Dim,T} = T
+    # MultiLineString
+    GeoInterface.coordtype(::GeoInterface.MultiLineStringTrait, geom::MultiLineString{Dim,T}) where {Dim,T} = T
+    # MultiPolygon
+    GeoInterface.coordtype(::GeoInterface.MultiPolygonTrait, geom::MultiPolygon{Dim,T}) where {Dim,T} = T
+    # Ngon (uses PolygonTrait)
+    GeoInterface.coordtype(::GeoInterface.PolygonTrait, geom::Ngon{Dim,T,N}) where {Dim,T,N} = T
+    # Simplex (can have PointTrait, LineStringTrait, or PolygonTrait depending on N)
+    GeoInterface.coordtype(::GeoInterface.PointTrait, geom::Simplex{Dim,T,1}) where {Dim,T} = T
+    GeoInterface.coordtype(::GeoInterface.LineStringTrait, geom::Simplex{Dim,T,2}) where {Dim,T} = T
+    GeoInterface.coordtype(::GeoInterface.PolygonTrait, geom::Simplex{Dim,T,3}) where {Dim,T} = T
+    # Mesh
     GeoInterface.coordtype(::GeoInterface.PolyhedralSurfaceTrait, geom::Mesh{Dim,T,E,V}) where {Dim,T,E,V} = T
 end
 
diff --git a/test/geointerface.jl b/test/geointerface.jl
index 1c62aee7..18d623b6 100644
--- a/test/geointerface.jl
+++ b/test/geointerface.jl
@@ -129,3 +129,61 @@ end
     @test ext.Y == (0.0f0, 1.0f0)
     @test ext.Z == (0.0f0, 1.0f0)
 end
+
+@testset "coordtype" begin
+    if isdefined(GeoInterface, :coordtype)
+        # Point
+        point_int = Point(2, 3)
+        point_float = Point(2.0, 3.0)
+        point_float32 = Point{2,Float32}(2.0, 3.0)
+        point_3d = Point{3,Float64}(1.0, 2.0, 3.0)
+        @test GeoInterface.coordtype(point_int) == Int
+        @test GeoInterface.coordtype(point_float) == Float64
+        @test GeoInterface.coordtype(point_float32) == Float32
+        @test GeoInterface.coordtype(point_3d) == Float64
+
+        # Line (AbstractGeometry)
+        line = Line(Point(2, 3), Point(4, 5))
+        line_float = Line(Point(2.0, 3.0), Point(4.0, 5.0))
+        @test GeoInterface.coordtype(line) == Int
+        @test GeoInterface.coordtype(line_float) == Float64
+
+        # LineString
+        linestring = LineString(Point{2,Int}[(10, 10), (20, 20), (10, 40)])
+        linestring_float = LineString(Point{2,Float64}[(10.0, 10.0), (20.0, 20.0)])
+        @test GeoInterface.coordtype(linestring) == Int
+        @test GeoInterface.coordtype(linestring_float) == Float64
+
+        # MultiPoint
+        mp = MultiPoint([Point(2, 3), Point(4, 5)])
+        mp_float = MultiPoint([Point(2.0, 3.0), Point(4.0, 5.0)])
+        @test GeoInterface.coordtype(mp) == Int
+        @test GeoInterface.coordtype(mp_float) == Float64
+
+        # MultiLineString
+        mls = MultiLineString([linestring, linestring])
+        mls_float = MultiLineString([linestring_float, linestring_float])
+        @test GeoInterface.coordtype(mls) == Int
+        @test GeoInterface.coordtype(mls_float) == Float64
+
+        # Polygon
+        poly_float32 = Polygon(rand(Point{2,Float32}, 5))
+        poly_float64 = Polygon(rand(Point{2,Float64}, 5))
+        @test GeoInterface.coordtype(poly_float32) == Float32
+        @test GeoInterface.coordtype(poly_float64) == Float64
+
+        # MultiPolygon
+        mpoly = MultiPolygon([poly_float32, poly_float32])
+        @test GeoInterface.coordtype(mpoly) == Float32
+
+        # Simplex (Triangle is Ngon which is a Simplex)
+        triangle = Triangle(Point(1, 2), Point(3, 4), Point(5, 6))
+        triangle_float = Triangle(Point(1.0, 2.0), Point(3.0, 4.0), Point(5.0, 6.0))
+        @test GeoInterface.coordtype(triangle) == Int
+        @test GeoInterface.coordtype(triangle_float) == Float64
+
+        # Mesh
+        mesh = triangle_mesh(Sphere(Point3f(0), 1))
+        @test GeoInterface.coordtype(mesh) == Float32
+    end
+end