Remove error from Envelope's TransformXY method

geom/type_envelope.go

@@ -281,13 +281,12 @@ func (e Envelope) Distance(o Envelope) (float64, bool) {
 }
 
 // TransformXY transforms this Envelope into another Envelope according to fn.
-// TODO: remove the error here as well.
-func (e Envelope) TransformXY(fn func(XY) XY) (Envelope, error) {
+func (e Envelope) TransformXY(fn func(XY) XY) Envelope {
 	min, max, ok := e.MinMaxXYs()
 	if !ok {
-		return Envelope{}, nil
+		return Envelope{}
 	}
-	return NewEnvelope([]XY{fn(min), fn(max)})
+	return newUncheckedEnvelope(fn(min), fn(max))
 }
 
 // AsBox converts this Envelope to an rtree.Box.

geom/type_envelope_test.go

@@ -566,8 +566,7 @@ func TestEnvelopeTransformXY(t *testing.T) {
 		{twoPtEnv(1, 2, 3, 4), twoPtEnv(1.5, 5, 4.5, 10)},
 	} {
 		t.Run(strconv.Itoa(i), func(t *testing.T) {
-			got, err := tc.input.TransformXY(transform)
-			expectNoErr(t, err)
+			got := tc.input.TransformXY(transform)
 			expectEnvEq(t, got, tc.want)
 		})
 	}
@@ -577,10 +576,9 @@ func BenchmarkEnvelopeTransformXY(b *testing.B) {
 	input := twoPtEnv(1, 2, 3, 4)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		_, err := input.TransformXY(func(in XY) XY {
+		input.TransformXY(func(in XY) XY {
 			return XY{in.X * 1.5, in.Y * 2.5}
 		})
-		expectNoErr(b, err)
 	}
 }