Tests for jump from click/cursor (#4297)

3 files changed, 98 insertions, 9 deletions

diff --git a/crates/typst-ide/Cargo.toml b/crates/typst-ide/Cargo.toml
index 01f7a106..4e87f99b 100644
--- a/crates/typst-ide/Cargo.toml
+++ b/crates/typst-ide/Cargo.toml
@@ -22,7 +22,7 @@ serde = { workspace = true }
 unscanny = { workspace = true }
 
 [dev-dependencies]
-typst-assets = { workspace = true }
+typst-assets = { workspace = true, features = ["fonts"] }
 typst-dev-assets = { workspace = true }
 once_cell = { workspace = true }
 
diff --git a/crates/typst-ide/src/jump.rs b/crates/typst-ide/src/jump.rs
index 45186d5b..3427a0c5 100644
--- a/crates/typst-ide/src/jump.rs
+++ b/crates/typst-ide/src/jump.rs
@@ -126,11 +126,8 @@ pub fn jump_from_cursor(
 
     let span = node.span();
     for (i, page) in document.pages.iter().enumerate() {
-        if let Some(pos) = find_in_frame(&page.frame, span) {
-            return Some(Position {
-                page: NonZeroUsize::new(i + 1).unwrap(),
-                point: pos,
-            });
+        if let Some(point) = find_in_frame(&page.frame, span) {
+            return Some(Position { page: NonZeroUsize::new(i + 1).unwrap(), point });
         }
     }
 
@@ -168,3 +165,72 @@ fn is_in_rect(pos: Point, size: Size, click: Point) -> bool {
         && pos.y <= click.y
         && pos.y + size.y >= click.y
 }
+
+#[cfg(test)]
+mod tests {
+    use std::num::NonZeroUsize;
+
+    use typst::eval::Tracer;
+    use typst::layout::{Abs, Point, Position};
+
+    use super::{jump_from_click, jump_from_cursor, Jump};
+    use crate::tests::TestWorld;
+
+    fn point(x: f64, y: f64) -> Point {
+        Point::new(Abs::pt(x), Abs::pt(y))
+    }
+
+    fn cursor(cursor: usize) -> Option<Jump> {
+        Some(Jump::Source(TestWorld::main_id(), cursor))
+    }
+
+    fn pos(page: usize, x: f64, y: f64) -> Option<Position> {
+        Some(Position {
+            page: NonZeroUsize::new(page).unwrap(),
+            point: point(x, y),
+        })
+    }
+
+    macro_rules! assert_approx_eq {
+        ($l:expr, $r:expr) => {
+            assert!(($l.to_raw() - $r.to_raw()).abs() < 0.1, "{:?} ≉ {:?}", $l, $r);
+        };
+    }
+
+    #[track_caller]
+    fn test_click(text: &str, click: Point, expected: Option<Jump>) {
+        let world = TestWorld::new(text);
+        let doc = typst::compile(&world, &mut Tracer::new()).unwrap();
+        assert_eq!(jump_from_click(&world, &doc, &doc.pages[0].frame, click), expected);
+    }
+
+    #[track_caller]
+    fn test_cursor(text: &str, cursor: usize, expected: Option<Position>) {
+        let world = TestWorld::new(text);
+        let doc = typst::compile(&world, &mut Tracer::new()).unwrap();
+        let pos = jump_from_cursor(&doc, &world.main, cursor);
+        assert_eq!(pos.is_some(), expected.is_some());
+        if let (Some(pos), Some(expected)) = (pos, expected) {
+            assert_eq!(pos.page, expected.page);
+            assert_approx_eq!(pos.point.x, expected.point.x);
+            assert_approx_eq!(pos.point.y, expected.point.y);
+        }
+    }
+
+    #[test]
+    fn test_jump_from_click() {
+        let s = "*Hello* #box[ABC] World";
+        test_click(s, point(0.0, 0.0), None);
+        test_click(s, point(70.0, 5.0), None);
+        test_click(s, point(45.0, 15.0), cursor(14));
+        test_click(s, point(48.0, 15.0), cursor(15));
+        test_click(s, point(72.0, 10.0), cursor(20));
+    }
+
+    #[test]
+    fn test_jump_from_cursor() {
+        let s = "*Hello* #box[ABC] World";
+        test_cursor(s, 12, None);
+        test_cursor(s, 14, pos(1, 37.55, 16.58));
+    }
+}
diff --git a/crates/typst-ide/src/lib.rs b/crates/typst-ide/src/lib.rs
index 117e75ab..1f8562fd 100644
--- a/crates/typst-ide/src/lib.rs
+++ b/crates/typst-ide/src/lib.rs
@@ -95,9 +95,10 @@ fn summarize_font_family<'a>(variants: impl Iterator<Item = &'a FontInfo>) -> Ec
 mod tests {
     use once_cell::sync::Lazy;
     use typst::diag::{FileError, FileResult};
-    use typst::foundations::{Bytes, Datetime};
+    use typst::foundations::{Bytes, Datetime, Smart};
+    use typst::layout::{Abs, Margin, PageElem};
     use typst::syntax::{FileId, Source};
-    use typst::text::{Font, FontBook};
+    use typst::text::{Font, FontBook, TextElem, TextSize};
     use typst::utils::LazyHash;
     use typst::{Library, World};
 
@@ -117,6 +118,12 @@ mod tests {
             let main = Source::detached(text);
             Self { main, base: &*BASE }
         }
+
+        /// The ID of the main file in a `TestWorld`.
+        pub fn main_id() -> FileId {
+            static ID: Lazy<FileId> = Lazy::new(|| Source::detached("").id());
+            *ID
+        }
     }
 
     impl World for TestWorld {
@@ -168,10 +175,26 @@ mod tests {
                 .collect();
 
             Self {
-                library: LazyHash::new(Library::default()),
+                library: LazyHash::new(library()),
                 book: LazyHash::new(FontBook::from_fonts(&fonts)),
                 fonts,
             }
         }
     }
+
+    /// The extended standard library for testing.
+    fn library() -> Library {
+        // Set page width to 120pt with 10pt margins, so that the inner page is
+        // exactly 100pt wide. Page height is unbounded and font size is 10pt so
+        // that it multiplies to nice round numbers.
+        let mut lib = Library::default();
+        lib.styles
+            .set(PageElem::set_width(Smart::Custom(Abs::pt(120.0).into())));
+        lib.styles.set(PageElem::set_height(Smart::Auto));
+        lib.styles.set(PageElem::set_margin(Margin::splat(Some(Smart::Custom(
+            Abs::pt(10.0).into(),
+        )))));
+        lib.styles.set(TextElem::set_size(TextSize(Abs::pt(10.0).into())));
+        lib
+    }
 }