start implementing PartialOrd for Directive

CHANGELOG.md

@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 * Support booking method in open account directive
 * implement `std::error::Error` for `ConversionError`
 * implement `FromStr` for `Directive<D>` where `D: Decimal`
+* implement `PartialOrd` for `Directive<D>`
 
 
 ## [2.0.0-beta.2] - 2023-07-08

src/lib.rs

@@ -43,6 +43,7 @@
 //! # Ok(()) }
 //! ```
 
+use std::cmp::Ordering;
 use std::{collections::HashSet, fs::File, io::Read, path::PathBuf, str::FromStr};
 
 use nom::{
@@ -292,6 +293,15 @@ impl<D: Decimal> FromStr for Directive<D> {
     }
 }
 
+impl<D> PartialOrd for Directive<D>
+where
+    Directive<D>: PartialEq,
+{
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.date.cmp(&other.date))
+    }
+}
+
 /// Directive specific content
 #[allow(missing_docs)]
 #[derive(Debug, Clone, PartialEq)]

tests/util_spec.rs

@@ -94,3 +94,16 @@ fn directive_from_str(
     let from_str: Directive<f64> = input.parse().unwrap();
     assert_eq!(from_file, from_str);
 }
+
+#[rstest]
+#[case("2023-07-09 open Assets:Cash", "2023-07-10 open Assets:Cash")]
+#[case("2023-07-09 open Assets:Cash", "2023-08-08 open Assets:Cash")]
+#[case("2023-07-09 open Assets:Cash", "2024-06-08 open Assets:Cash")]
+fn directive_ord(#[case] smaller: Directive<f64>, #[case] bigger: Directive<f64>) {
+    assert!(smaller < bigger);
+    assert!(smaller <= bigger);
+    assert_eq!(smaller, smaller.clone());
+    assert_eq!(bigger, bigger.clone());
+    assert!(bigger > smaller);
+    assert!(bigger >= smaller);
+}