add trait promotion without array (#159)

* add trait promotion without array

* support FeatureCollection + tests

* Apply suggestion from code review

* Get tests working, propagate crs and extent up

* Update src/wrappers.jl

---------

Co-authored-by: Anshul Singhvi <anshulsinghvi@gmail.com>
Co-authored-by: Rafael Schouten <rafaelschouten@gmail.com>

src/wrappers.jl

@@ -172,16 +172,23 @@ for (geomtype, trait, childtype, child_trait, length_check, nesting) in (
         # But not if geom is already a WrapperGeometry
         convert(::Type{$geomtype}, ::$trait, geom::$geomtype) = geom
     end
+
     @eval function $geomtype{Z,M}(geom::T; extent::E=nothing, crs::C=nothing) where {Z,M,T,E,C}
         Z isa Union{Bool,Nothing} || throw(ArgumentError("Z Parameter must be `true`, `false` or `nothing`"))
         M isa Union{Bool,Nothing} || throw(ArgumentError("M Parameter must be `true`, `false` or `nothing`"))
 
-        # Wrap some geometry at the same level
+        # Is geom a single geometry ?
         if isgeometry(geom)
-            geomtrait(geom) isa $trait || _argument_error(T, $trait)
-            Z1 = isnothing(Z) ? is3d(geom) : Z
-            M1 = isnothing(M) ? ismeasured(geom) : M
-            return $geomtype{Z1,M1,T,E,C}(geom, extent, crs)
+            if geomtrait(geom) isa $child_trait
+                # If geom is a child_trait, then make geom a vector and call again
+                return $geomtype([geom]; extent, crs)
+            else
+                # Wrap some geometry at the same level
+                geomtrait(geom) isa $trait || _argument_error(T, $trait)
+                Z1 = isnothing(Z) ? is3d(geom) : Z
+                M1 = isnothing(M) ? ismeasured(geom) : M
+                return $geomtype{Z1,M1,T,E,C}(geom, extent, crs)
+            end
 
         # Otherwise wrap an array of child geometries
         elseif geom isa AbstractArray
@@ -428,6 +435,13 @@ end
 function FeatureCollection(parent; crs=nothing, extent=nothing)
     if isfeaturecollection(parent)
         FeatureCollection(parent, crs, extent)
+    elseif isfeature(parent)
+        # If `parent` is a single feature, wrap it in a featurecollection
+        FeatureCollection(
+            [parent], 
+            isnothing(crs) ? Wrappers.crs(parent) : crs, 
+            isnothing(extent) ? Wrappers.extent(parent) : extent
+        )
     else
         features = (parent isa AbstractArray) ? parent : collect(parent) 
         all(f -> isfeature(f), features) || _child_feature_error()

test/test_wrappers.jl

@@ -152,6 +152,7 @@ linearring_crs = GI.LinearRing(linearring; crs=EPSG(4326))
 
 # Polygon
 polygon = GI.Polygon([linearring, linearring])
+@test GI.Polygon([linearring]) == GI.Polygon(linearring)
 @test polygon == GI.Polygon(polygon)
 @test GI.getgeom(polygon, 1) === linearring
 @test collect(GI.getgeom(polygon)) == [linearring, linearring]
@@ -179,6 +180,7 @@ polygon3d = GI.Polygon([linearring3d, linearring3d])
 # MultiPoint
 multipoint = GI.MultiPoint([(1, 2), (3, 4), (3, 2), (1, 4), (7, 8), (9, 10)])
 @test multipoint == GI.MultiPoint(multipoint)
+@test GI.MultiPoint([(1, 2)]) == GI.MultiPoint((1, 2))
 @test GI.getgeom(multipoint, 1) === (1, 2)
 @test !GI.is3d(multipoint)
 @test GI.ncoord(multipoint) == 2
@@ -192,6 +194,7 @@ multipoint_crs = GI.MultiPoint(multipoint; crs=EPSG(4326))
 # GeometryCollection
 geoms = [line, linestring, linearring, multipoint, (1, 2)]
 collection = GI.GeometryCollection(geoms)
+@test GI.GeometryCollection([line]) == GI.GeometryCollection(line)
 @test collection == GI.GeometryCollection(collection)
 @test GI.getgeom(collection) == geoms
 @test GI.testgeometry(collection)
@@ -205,6 +208,7 @@ collection_crs = GI.GeometryCollection(collection; crs=EPSG(4326))
 # MultiCurve
 multicurve = GI.MultiCurve([linestring, linearring])
 @test collect(GI.getpoint(multicurve)) == vcat(collect(GI.getpoint(linestring)), collect(GI.getpoint(linearring)))
+@test GI.MultiCurve([linestring]) == GI.MultiCurve(linestring)
 @test multicurve == GI.MultiCurve(multicurve)
 @test GI.getgeom(multicurve, 1) === linestring
 @test !GI.is3d(multicurve)
@@ -221,6 +225,7 @@ multicurve_crs = GI.MultiCurve(multicurve; crs=EPSG(4326))
 polygon = GI.Polygon([linearring, linearring])
 multipolygon = GI.MultiPolygon([polygon])
 @test multipolygon == GI.MultiPolygon(multipolygon)
+@test multipolygon == GI.MultiPolygon(polygon)
 @test GI.getgeom(multipolygon, 1) === polygon
 @test !GI.is3d(multipolygon)
 @test GI.ncoord(multipolygon) == 2
@@ -238,6 +243,7 @@ multipolygon_crs = GI.MultiPolygon(multipolygon; crs=EPSG(4326))
 # PolyhedralSurface
 polyhedralsurface = GI.PolyhedralSurface([polygon, polygon])
 @test polyhedralsurface == GI.PolyhedralSurface(polyhedralsurface)
+@test GI.PolyhedralSurface(polygon) == GI.PolyhedralSurface(polygon)
 @test !GI.is3d(polyhedralsurface)
 @test GI.ncoord(polyhedralsurface) == 2
 @test @inferred(GI.extent(polyhedralsurface)) == Extent(X=(1, 5), Y=(2, 6))
@@ -281,7 +287,11 @@ feature = GI.Feature(multipolygon;
 @test_throws ArgumentError GI.Feature(:not_a_feature; properties=(x=1, y=2, z=3))
 
 # Feature Collection
-fc = GI.FeatureCollection([feature]; crs=EPSG(4326), extent=GI.extent(feature))
+fc_unwrapped = GI.FeatureCollection(feature; crs=EPSG(4326), extent=GI.extent(feature))
+fc = GI.FeatureCollection(fc_unwrapped.parent; crs=EPSG(4326), extent=GI.extent(feature)) # so that `==` works since the underlying array is the same
+@test fc_unwrapped == fc
+@test GI.crs(fc) == GI.crs(GI.FeatureCollection(feature; crs=EPSG(4326), extent=GI.extent(feature)))
+@test GI.extent(fc) == GI.extent(GI.FeatureCollection(feature; crs=EPSG(4326), extent=GI.extent(feature)))
 @test fc === GI.FeatureCollection(fc)
 @test GI.crs(fc) == EPSG(4326)
 @test GI.extent(fc) == fc.extent