code review changes

internal/env/parse_test.go

@@ -12,7 +12,7 @@ import (
 
 func TestParseURL(t *testing.T) {
 	type tcase struct {
-		in          string
+		in          any
 		expected    *url.URL
 		expectedErr error
 	}
@@ -57,6 +57,10 @@ func TestParseURL(t *testing.T) {
 			in:          "https://go-spatial.org/tegola/_20_%+off_60000_",
 			expectedErr: url.EscapeError(""),
 		},
+		"nil": {
+			in:       nil,
+			expected: nil,
+		},
 	}
 
 	for name, tc := range tests {

internal/env/types.go

@@ -171,6 +171,10 @@ func (t *URL) UnmarshalTOML(v any) error {
 		return err
 	}
 
+	if u == nil {
+		return nil
+	}
+
 	*t = URL(*u)
 	return nil
 }

internal/env/types_test.go

@@ -0,0 +1,69 @@
+package env_test
+
+import (
+	"errors"
+	"net/url"
+	"testing"
+
+	"github.com/go-spatial/tegola/internal/env"
+	"github.com/go-test/deep"
+)
+
+func TestURLUnmarshalTOML(t *testing.T) {
+	type tcase struct {
+		in          any
+		expected    env.URL
+		expectedErr error
+	}
+
+	fn := func(tc tcase) func(*testing.T) {
+		return func(t *testing.T) {
+			got := env.URL{}
+			err := got.UnmarshalTOML(tc.in)
+			if tc.expectedErr != nil {
+				if err == nil {
+					t.Errorf("expected err %v, got nil", tc.expectedErr.Error())
+					return
+				}
+
+				// compare error messages
+				if errors.Is(tc.expectedErr, err) {
+					t.Errorf("invalid error. expected %v, got %v", tc.expectedErr, err)
+					return
+				}
+
+				return
+			}
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+
+			if diff := deep.Equal(got, tc.expected); diff != nil {
+				t.Fatalf("expected does not match go: %v", diff)
+			}
+		}
+	}
+
+	tests := map[string]tcase{
+		"happy path": {
+			in: "https://go-spatial.org/tegola",
+			expected: env.URL{
+				Scheme: "https",
+				Host:   "go-spatial.org",
+				Path:   "/tegola",
+			},
+		},
+		"invalid url escape": {
+			in:          "https://go-spatial.org/tegola/_20_%+off_60000_",
+			expectedErr: url.EscapeError(""),
+		},
+		"nil": {
+			in:       nil,
+			expected: env.URL{},
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, fn(tc))
+	}
+}