expanded date addition test coverage and added optimized snapshot test

Author: SATVIKsynopsis

components/calendar/tests/date_optimized_snapshot.rs

@@ -0,0 +1,118 @@
+// This file is part of ICU4X. For terms of use, please see the file
+// called LICENSE at the top level of the ICU4X source tree
+// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
+
+use icu_calendar::{AnyCalendar, AnyCalendarKind, Date};
+use std::fmt::Write;
+
+#[test]
+fn test_generate_dates_and_durations_for_review() {
+    let calendars = vec![
+        AnyCalendarKind::Iso,
+        AnyCalendarKind::Gregorian,
+        AnyCalendarKind::Buddhist,
+        AnyCalendarKind::Chinese,
+        AnyCalendarKind::Coptic,
+        AnyCalendarKind::Dangi,
+        AnyCalendarKind::Ethiopian,
+        AnyCalendarKind::EthiopianAmeteAlem,
+        AnyCalendarKind::Hebrew,
+        AnyCalendarKind::HijriSimulatedMecca,
+        AnyCalendarKind::HijriTabularTypeIIFriday,
+        AnyCalendarKind::HijriTabularTypeIIThursday,
+        AnyCalendarKind::HijriUmmAlQura,
+        AnyCalendarKind::Indian,
+        AnyCalendarKind::Japanese,
+        AnyCalendarKind::JapaneseExtended,
+        AnyCalendarKind::Persian,
+        AnyCalendarKind::Roc,
+    ];
+
+   
+    let iso_dates = vec![
+        (2000, 1, 1),
+        (2000, 2, 28),
+        (2000, 2, 29),
+        (2000, 3, 1),
+        (2001, 2, 28),
+        (2004, 2, 28),
+        (2004, 2, 29),
+        (2004, 3, 1),
+        (2004, 12, 31),
+    ];
+
+    
+    let mut durations: Vec<(i32, i32, i32)> = Vec::new();
+
+    for d in -65..=65 {
+        durations.push((0, 0, d));
+    }
+
+    for m in -30..=30 {
+        durations.push((0, m, 0));
+    }
+
+    for md in -30..=30 {
+        let day = if md < 0 { -1 } else if md == 0 { 0 } else { 1 };
+        durations.push((0, md, day));
+    }
+
+    for y in -10..=10 {
+        durations.push((y, 0, 0));
+    }
+
+    for ym in -10..=10 {
+        let month = if ym < 0 { -1 } else if ym == 0 { 0 } else { 1 };
+        durations.push((ym, month, 0));
+    }
+
+    for yd in -10..=10 {
+        let day = if yd < 0 { -1 } else if yd == 0 { 0 } else { 1 };
+        durations.push((yd, 0, day));
+    }
+
+    for ymd in -10..=10 {
+        let (month, day) = if ymd < 0 { (-1, -1) } else if ymd == 0 { (0, 0) } else { (1, 1) };
+        durations.push((ymd, month, day));
+    }
+
+  
+    let mut output = String::new();
+
+    writeln!(&mut output, "Durations total: {}", durations.len()).unwrap();
+    writeln!(&mut output).unwrap();
+
+    for cal_kind in &calendars {
+        let cal = AnyCalendar::new(*cal_kind);
+        writeln!(&mut output, "Calendar: {:?}", cal_kind).unwrap();
+
+        for (y, m, d) in &iso_dates {
+
+            let start_date = Date::try_new_iso(*y, *m, *d)
+                .expect("Valid ISO date")
+                .to_calendar(cal.clone());
+
+            writeln!(&mut output, "  START: {:04}-{:02}-{:02} -> {:?}", y, m, d, start_date)
+                .unwrap();
+
+            
+            let show_n = 8usize;
+            for (i, dur) in durations.iter().enumerate() {
+                if i < show_n || i + show_n >= durations.len() {
+                    writeln!(&mut output, "    +{:>4}Y {:>4}M {:>4}D", dur.0, dur.1, dur.2).unwrap();
+                } else if i == show_n {
+                    writeln!(&mut output, "    ... {} omitted ...", durations.len() - (show_n * 2)).unwrap();
+                }
+            }
+
+            writeln!(&mut output).unwrap();
+        }
+
+        writeln!(&mut output).unwrap();
+    }
+
+   
+    assert!(!output.is_empty());
+
+    println!("{}", output);
+}