Make route colors optional

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 description = "Read GTFS (public transit timetables) files"
 name = "gtfs-structures"
-version = "0.44.0"
+version = "0.45.0"
 authors = [
     "Tristram Gräbener <tristramg@gmail.com>",
     "Antoine Desbordes <antoine.desbordes@gmail.com>",

src/objects.rs

@@ -340,20 +340,20 @@ pub struct Route {
     pub order: Option<u32>,
     /// Route color designation that matches public facing material
     #[serde(
-        deserialize_with = "deserialize_route_color",
-        serialize_with = "serialize_color",
+        deserialize_with = "deserialize_optional_color",
+        serialize_with = "serialize_optional_color",
         rename = "route_color",
-        default = "default_route_color"
+        default
     )]
-    pub color: RGB8,
+    pub color: Option<RGB8>,
     /// Legible color to use for text drawn against a background of [Route::route_color]
     #[serde(
-        deserialize_with = "deserialize_route_text_color",
-        serialize_with = "serialize_color",
+        deserialize_with = "deserialize_optional_color",
+        serialize_with = "serialize_optional_color",
         rename = "route_text_color",
         default
     )]
-    pub text_color: RGB8,
+    pub text_color: Option<RGB8>,
     /// Indicates whether a rider can board the transit vehicle anywhere along the vehicle’s travel path
     #[serde(default)]
     pub continuous_pickup: ContinuousPickupDropOff,
@@ -362,6 +362,20 @@ pub struct Route {
     pub continuous_drop_off: ContinuousPickupDropOff,
 }
 
+impl Route {
+    /// Legible color to use for text drawn against a background of [Route::route_color]
+    /// Defaults to white (FFFFFF) when omitted or left empty.
+    pub fn text_color(&self) -> RGB8 {
+        self.text_color.unwrap_or_default()
+    }
+
+    /// Legible color to use for text drawn against a background of [Route::route_color]
+    /// Defaults to black (000000) when omitted or left empty.
+    pub fn color(&self) -> RGB8 {
+        self.color.unwrap_or_else(default_route_color)
+    }
+}
+
 impl Type for Route {
     fn object_type(&self) -> ObjectType {
         ObjectType::Route
@@ -377,9 +391,9 @@ impl Id for Route {
 impl fmt::Display for Route {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         if let Some(long_name) = self.long_name.as_ref() {
-            write!(f, "{}", long_name)
+            write!(f, "{long_name}")
         } else if let Some(short_name) = self.short_name.as_ref() {
-            write!(f, "{}", short_name)
+            write!(f, "{short_name}")
         } else {
             write!(f, "{}", self.id)
         }

src/serde_helpers.rs

@@ -139,13 +139,7 @@ where
     }
 }
 
-pub fn parse_color(
-    s: &str,
-    default: impl std::ops::FnOnce() -> RGB8,
-) -> Result<RGB8, crate::Error> {
-    if s.is_empty() {
-        return Ok(default());
-    }
+pub fn parse_color(s: &str) -> Result<RGB8, crate::Error> {
     if s.len() != 6 {
         return Err(crate::Error::InvalidColor(s.to_owned()));
     }
@@ -158,26 +152,24 @@ pub fn parse_color(
     Ok(RGB8::new(r, g, b))
 }
 
-pub fn deserialize_route_color<'de, D>(de: D) -> Result<RGB8, D::Error>
-where
-    D: Deserializer<'de>,
-{
-    String::deserialize(de)
-        .and_then(|s| parse_color(&s, default_route_color).map_err(de::Error::custom))
-}
-
-pub fn deserialize_route_text_color<'de, D>(de: D) -> Result<RGB8, D::Error>
+pub fn deserialize_optional_color<'de, D>(de: D) -> Result<Option<RGB8>, D::Error>
 where
     D: Deserializer<'de>,
 {
-    String::deserialize(de).and_then(|s| parse_color(&s, RGB8::default).map_err(de::Error::custom))
+    Option::<&str>::deserialize(de)?
+        .map(|s| parse_color(s).map_err(de::Error::custom))
+        .transpose()
 }
 
-pub fn serialize_color<S>(color: &RGB8, serializer: S) -> Result<S::Ok, S::Error>
+pub fn serialize_optional_color<S>(color: &Option<RGB8>, serializer: S) -> Result<S::Ok, S::Error>
 where
     S: Serializer,
 {
-    serializer.serialize_str(format!("{:02X}{:02X}{:02X}", color.r, color.g, color.b).as_str())
+    match color {
+        Some(color) => serializer
+            .serialize_str(format!("{:02X}{:02X}{:02X}", color.r, color.g, color.b).as_str()),
+        None => serializer.serialize_none(),
+    }
 }
 
 pub fn default_route_color() -> RGB8 {

src/tests.rs

@@ -84,19 +84,19 @@ fn read_routes() {
     let gtfs = Gtfs::from_path("fixtures/basic").expect("impossible to read gtfs");
     assert_eq!(3, gtfs.routes.len());
     assert_eq!(RouteType::Bus, gtfs.get_route("1").unwrap().route_type);
-    assert_eq!(RGB8::new(0, 0, 0), gtfs.get_route("1").unwrap().color);
+    assert_eq!(RGB8::new(0, 0, 0), gtfs.get_route("1").unwrap().color());
     assert_eq!(
         RGB8::new(255, 255, 255),
-        gtfs.get_route("1").unwrap().text_color
+        gtfs.get_route("1").unwrap().text_color()
     );
-    assert_eq!(RGB8::new(0, 0, 0), gtfs.get_route("1").unwrap().color);
+    assert_eq!(RGB8::new(0, 0, 0), gtfs.get_route("1").unwrap().color());
     assert_eq!(
         RGB8::new(0, 0, 0),
-        gtfs.get_route("default_colors").unwrap().text_color
+        gtfs.get_route("default_colors").unwrap().text_color()
     );
     assert_eq!(
         RGB8::new(255, 255, 255),
-        gtfs.get_route("default_colors").unwrap().color
+        gtfs.get_route("default_colors").unwrap().color()
     );
     assert_eq!(Some(1), gtfs.get_route("1").unwrap().order);
     assert_eq!(
@@ -440,8 +440,8 @@ fn read_only_required_fields() {
     let fare_attribute = gtfs.fare_attributes.get("50").unwrap();
     let feed = &gtfs.feed_info[0];
     let shape = &gtfs.shapes.get("A_shp").unwrap()[0];
-    assert_eq!(route.color, RGB8::new(255, 255, 255));
-    assert_eq!(route.text_color, RGB8::new(0, 0, 0));
+    assert_eq!(route.color(), RGB8::new(255, 255, 255));
+    assert_eq!(route.text_color(), RGB8::new(0, 0, 0));
     assert_eq!(fare_attribute.transfer_duration, None);
     assert_eq!(feed.start_date, None);
     assert_eq!(feed.end_date, None);