chrono: Add support for NaiveDate (#56)

* chrono: Add support for NaiveDate

* Fix actual conversion of NaiveDate to Int64

* Do not use duplicate method names

* Include test method in tests

* Fix deprecation warnings

* Apply formatting

src/chrono.rs

@@ -53,6 +53,26 @@ impl IntoDart for chrono::DateTime<chrono::Local> {
     }
 }
 
+impl IntoDart for chrono::NaiveDate {
+    /// on the other side of FFI, value should be reconstructed like:
+    ///
+    /// - hydrate into Dart [DateTime](https://api.dart.dev/stable/2.18.0/dart-core/DateTime/DateTime.fromMicrosecondsSinceEpoch.html)
+    ///   `DateTime.fromMicrosecondsSinceEpoch(raw, isUtc: true);`
+    ///
+    /// - hydrate into Rust [NaiveDateTime](chrono::NaiveDate)
+    ///   ```rust,ignore
+    ///   let s = (raw / 1_000_000) as i64;
+    ///   let ns = (raw.rem_euclid(1_000_000) * 1_000) as u32;
+    ///   chrono::NaiveDateTime::from_timestamp(s, ns)
+    ///   ```
+    ///
+    ///   note that it could overflow under the same conditions as of [chrono::NaiveDateTime::from_timestamp](https://docs.rs/chrono/0.4.20/chrono/naive/struct.NaiveDateTime.html#method.from_timestamp)
+    fn into_dart(self) -> DartCObject {
+        self.signed_duration_since(chrono::NaiveDate::MIN)
+            .into_dart()
+    }
+}
+
 impl IntoDart for chrono::NaiveDateTime {
     /// on the other side of FFI, value should be reconstructed like:
     ///
@@ -137,6 +157,32 @@ impl DartTypedDataTypeTrait for chrono::DateTime<chrono::Local> {
     }
 }
 
+impl IntoDart for Vec<chrono::NaiveDate> {
+    fn into_dart(self) -> DartCObject {
+        self.iter()
+            .map(|lhs| lhs.signed_duration_since(chrono::NaiveDate::MIN))
+            .collect::<Vec<_>>()
+            .into_dart()
+    }
+}
+
+impl<const N: usize> IntoDart for [chrono::NaiveDate; N] {
+    fn into_dart(self) -> DartCObject {
+        let vec: Vec<_> = self.into();
+        vec.into_dart()
+    }
+}
+
+impl DartTypedDataTypeTrait for chrono::NaiveDate {
+    fn dart_typed_data_type() -> DartTypedDataType {
+        DartTypedDataType::Int64
+    }
+
+    fn function_pointer_of_free_zero_copy_buffer() -> DartHandleFinalizer {
+        free_zero_copy_buffer_i64
+    }
+}
+
 impl IntoDart for Vec<chrono::NaiveDateTime> {
     fn into_dart(self) -> DartCObject {
         self.iter()

tests/containers.rs

@@ -197,6 +197,7 @@ fn main() {
     assert!(isolate.post(return_backtrace()));
     #[cfg(feature = "chrono")]
     {
+        assert!(isolate.post(return_chrono_naive_date()));
         assert!(isolate.post(return_chrono_naive_date_time()));
         assert!(isolate.post(return_chrono_date_time_utc()));
         assert!(isolate.post(return_chrono_date_time_local()));
@@ -236,9 +237,17 @@ fn return_backtrace() -> backtrace::Backtrace {
     backtrace::Backtrace::new()
 }
 
+#[cfg(feature = "chrono")]
+fn return_chrono_naive_date() -> chrono::NaiveDate {
+    chrono::NaiveDate::from_ymd_opt(1776, 7, 4)
+        .expect("The input date for testing is required to be valid")
+}
 #[cfg(feature = "chrono")]
 fn return_chrono_naive_date_time() -> chrono::NaiveDateTime {
-    chrono::NaiveDate::from_ymd(2016, 7, 8).and_hms_micro(9, 10, 11, 123_456)
+    chrono::NaiveDate::from_ymd_opt(2016, 7, 8)
+        .map(|nd| nd.and_hms_micro_opt(9, 10, 11, 123_456))
+        .flatten()
+        .expect("The input date and time for testing are required to be valid")
 }
 #[cfg(feature = "chrono")]
 fn return_chrono_date_time_utc() -> chrono::DateTime<chrono::Utc> {