Add support for date & time handling (#435)

3 files changed, 96 insertions, 2 deletions

diff --git a/tests/src/benches.rs b/tests/src/benches.rs
index 9e9b98d0..aeddcaf9 100644
--- a/tests/src/benches.rs
+++ b/tests/src/benches.rs
@@ -3,7 +3,7 @@ use std::path::Path;
 use comemo::{Prehashed, Track, Tracked};
 use iai::{black_box, main, Iai};
 use typst::diag::{FileError, FileResult};
-use typst::eval::Library;
+use typst::eval::{Datetime, Library};
 use typst::font::{Font, FontBook};
 use typst::geom::Color;
 use typst::syntax::{Source, SourceId};
@@ -147,4 +147,8 @@ impl World for BenchWorld {
     fn file(&self, path: &Path) -> FileResult<Buffer> {
         Err(FileError::NotFound(path.into()))
     }
+
+    fn today(&self, _: Option<i64>) -> Option<Datetime> {
+        Some(Datetime::from_ymd(1970, 1, 1).unwrap())
+    }
 }
diff --git a/tests/src/tests.rs b/tests/src/tests.rs
index f295869f..c2d0cc68 100644
--- a/tests/src/tests.rs
+++ b/tests/src/tests.rs
@@ -22,7 +22,7 @@ use walkdir::WalkDir;
 
 use typst::diag::{bail, FileError, FileResult};
 use typst::doc::{Document, Frame, FrameItem, Meta};
-use typst::eval::{func, Library, Value};
+use typst::eval::{func, Datetime, Library, Value};
 use typst::font::{Font, FontBook};
 use typst::geom::{Abs, Color, RgbaColor, Sides, Smart};
 use typst::syntax::{Source, SourceId, Span, SyntaxNode};
@@ -296,6 +296,10 @@ impl World for TestWorld {
             .get_or_init(|| read(path).map(Buffer::from))
             .clone()
     }
+
+    fn today(&self, _: Option<i64>) -> Option<Datetime> {
+        Some(Datetime::from_ymd(1970, 1, 1).unwrap())
+    }
 }
 
 impl TestWorld {
diff --git a/tests/typ/compute/construct.typ b/tests/typ/compute/construct.typ
index ee0a24b0..9c05a6d0 100644
--- a/tests/typ/compute/construct.typ
+++ b/tests/typ/compute/construct.typ
@@ -73,3 +73,89 @@
 
 ---
 #assert(range(2, 5) == (2, 3, 4))
+
+---
+// Test displaying of dates.
+#test(datetime(year: 2023, month: 4, day: 29).display(), "2023-04-29")
+#test(datetime(year: 2023, month: 4, day: 29).display("[year]"), "2023")
+#test(
+  datetime(year: 2023, month: 4, day: 29)
+    .display("[year repr:last_two]"),
+  "23",
+)
+#test(
+  datetime(year: 2023, month: 4, day: 29)
+    .display("[year] [month repr:long] [day] [week_number] [weekday]"),
+  "2023 April 29 17 Saturday",
+)
+
+// Test displaying of times
+#test(datetime(hour: 14, minute: 26, second: 50).display(), "14:26:50")
+#test(datetime(hour: 14, minute: 26, second: 50).display("[hour]"), "14")
+#test(
+  datetime(hour: 14, minute: 26, second: 50)
+    .display("[hour repr:12 padding:none]"),
+  "2",
+)
+#test(
+  datetime(hour: 14, minute: 26, second: 50)
+    .display("[hour], [minute], [second]"), "14, 26, 50",
+)
+
+// Test displaying of datetimes
+#test(
+  datetime(year: 2023, month: 4, day: 29, hour: 14, minute: 26, second: 50).display(),
+  "2023-04-29 14:26:50",
+)
+
+// Test getting the year/month/day etc. of a datetime
+#let d = datetime(year: 2023, month: 4, day: 29, hour: 14, minute: 26, second: 50)
+#test(d.year(), 2023)
+#test(d.month(), 4)
+#test(d.weekday(), 6)
+#test(d.day(), 29)
+#test(d.hour(), 14)
+#test(d.minute(), 26)
+#test(d.second(), 50)
+
+#let e = datetime(year: 2023, month: 4, day: 29)
+#test(e.hour(), none)
+#test(e.minute(), none)
+#test(e.second(), none)
+
+// Test today
+#test(datetime.today().display(), "1970-01-01")
+#test(datetime.today(offset: auto).display(), "1970-01-01")
+#test(datetime.today(offset: 2).display(), "1970-01-01")
+
+---
+// Error: 10-12 at least one of date or time must be fully specified
+#datetime()
+
+---
+// Error: 10-42 time is invalid
+#datetime(hour: 25, minute: 0, second: 0)
+
+---
+// Error: 10-41 date is invalid
+#datetime(year: 2000, month: 2, day: 30)
+
+---
+// Error: 26-35 missing closing bracket for bracket at index 0
+#datetime.today().display("[year")
+
+---
+// Error: 26-39 invalid component name 'nothing' at index 1
+#datetime.today().display("[nothing]")
+
+---
+// Error: 26-51 invalid modifier 'wrong' at index 6
+#datetime.today().display("[year wrong:last_two]")
+
+---
+// Error: 26-34 expected component name at index 2
+#datetime.today().display("  []")
+
+---
+// Error: 26-36 failed to format datetime in the requested format
+#datetime.today().display("[hour]")