adjust valid day values

Author: Lollyde

Cargo.lock

@@ -23,6 +23,7 @@ test_lib = []
 
 # Template dependencies
 chrono = { version = "0.4.38", optional = true }
+const-str = "0.7.0"
 dhat = { version = "0.3.3", optional = true }
 pico-args = "0.5.0"
 tinyjson = "2.5.1"

Cargo.toml

@@ -133,7 +133,7 @@ fn main() {
                     None => {
                         eprintln!(
                             "`today` command can only be run between the 1st and \
-                            the 25th of december. Please use `scaffold` with a specific day."
+                            the 12th of december. Please use `scaffold` with a specific day."
                         );
                         process::exit(1)
                     }

src/main.rs

@@ -8,7 +8,8 @@ use chrono::{Datelike, FixedOffset, Utc};
 #[cfg(feature = "today")]
 const SERVER_UTC_OFFSET: i32 = -5;
 
-/// A valid day number of advent (i.e. an integer in range 1 to 25).
+/// A valid day number of advent (i.e. an integer in range 1 to 12).
+/// Before the year 2025, allow integers up to 25.
 ///
 /// # Display
 /// This value displays as a two digit number.
@@ -21,11 +22,20 @@ const SERVER_UTC_OFFSET: i32 = -5;
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct Day(u8);
 
+macro_rules! day_count {
+    () => {
+        match const_str::parse!(env!("AOC_YEAR"), u16) < 2025 {
+            true => 25u8,
+            false => 12u8,
+        }
+    }
+}
+
 impl Day {
     /// Creates a [`Day`] from the provided value if it's in the valid range,
     /// returns [`None`] otherwise.
     pub const fn new(day: u8) -> Option<Self> {
-        if day == 0 || day > 25 {
+        if day == 0 || day > day_count!() {
             return None;
         }
         Some(Self(day))
@@ -39,11 +49,12 @@ impl Day {
 
 #[cfg(feature = "today")]
 impl Day {
-    /// Returns the current day if it's between the 1st and the 25th of december, `None` otherwise.
+    /// Returns the current day if it's between the 1st and the 12th of december, `None` otherwise.
+    /// Accepts days up to the 25th if the Year is before 2025.
     pub fn today() -> Option<Self> {
         let offset = FixedOffset::east_opt(SERVER_UTC_OFFSET * 3600)?;
         let today = Utc::now().with_timezone(&offset);
-        if today.month() == 12 && today.day() <= 25 {
+        if today.month() == day_count!() as u32 && today.day() <= day_count!() as u32 {
             Self::new(u8::try_from(today.day()).ok()?)
         } else {
             None
@@ -88,18 +99,18 @@ impl Error for DayFromStrError {}
 
 impl Display for DayFromStrError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.write_str("expecting a day number between 1 and 25")
+        f.write_str("expecting a day number between 1 and {{day_count!()}}")
     }
 }
 
 /* -------------------------------------------------------------------------- */
 
-/// An iterator that yields every day of advent from the 1st to the 25th.
+/// An iterator that yields every day of advent from the 1st to the 12th.
 pub fn all_days() -> AllDays {
     AllDays::new()
 }
 
-/// An iterator that yields every day of advent from the 1st to the 25th.
+/// An iterator that yields every day of advent from the 1st to the 12th.
 pub struct AllDays {
     current: u8,
 }
@@ -115,10 +126,10 @@ impl Iterator for AllDays {
     type Item = Day;
 
     fn next(&mut self) -> Option<Self::Item> {
-        if self.current > 25 {
+        if self.current > day_count!() {
             return None;
         }
-        // NOTE: the iterator starts at 1 and we have verified that the value is not above 25.
+        // NOTE: the iterator starts at 1 and we have verified that the value is not above 12.
         let day = Day(self.current);
         self.current += 1;
 
@@ -134,7 +145,7 @@ macro_rules! day {
     ($day:expr) => {
         const {
             $crate::template::Day::new($day)
-                .expect("invalid day number, expecting a value between 1 and 25")
+                .expect("invalid day number, expecting a value between 1 and 12")
         }
     };
 }
@@ -161,19 +172,21 @@ mod tests {
         assert_eq!(iter.next(), Some(Day(10)));
         assert_eq!(iter.next(), Some(Day(11)));
         assert_eq!(iter.next(), Some(Day(12)));
-        assert_eq!(iter.next(), Some(Day(13)));
-        assert_eq!(iter.next(), Some(Day(14)));
-        assert_eq!(iter.next(), Some(Day(15)));
-        assert_eq!(iter.next(), Some(Day(16)));
-        assert_eq!(iter.next(), Some(Day(17)));
-        assert_eq!(iter.next(), Some(Day(18)));
-        assert_eq!(iter.next(), Some(Day(19)));
-        assert_eq!(iter.next(), Some(Day(20)));
-        assert_eq!(iter.next(), Some(Day(21)));
-        assert_eq!(iter.next(), Some(Day(22)));
-        assert_eq!(iter.next(), Some(Day(23)));
-        assert_eq!(iter.next(), Some(Day(24)));
-        assert_eq!(iter.next(), Some(Day(25)));
+        if day_count!() > 12 {
+            assert_eq!(iter.next(), Some(Day(13)));
+            assert_eq!(iter.next(), Some(Day(14)));
+            assert_eq!(iter.next(), Some(Day(15)));
+            assert_eq!(iter.next(), Some(Day(16)));
+            assert_eq!(iter.next(), Some(Day(17)));
+            assert_eq!(iter.next(), Some(Day(18)));
+            assert_eq!(iter.next(), Some(Day(19)));
+            assert_eq!(iter.next(), Some(Day(20)));
+            assert_eq!(iter.next(), Some(Day(21)));
+            assert_eq!(iter.next(), Some(Day(22)));
+            assert_eq!(iter.next(), Some(Day(23)));
+            assert_eq!(iter.next(), Some(Day(24)));
+            assert_eq!(iter.next(), Some(Day(25)));
+        }
         assert_eq!(iter.next(), None);
     }
 }