Better expansion behaviour 🐪

This makes expansion behaviour inheritable by placing it into the area and passing it down during layouting instead of computing some approximation of what we want during execution.

3 files changed, 16 insertions, 3 deletions

diff --git a/tests/ref/expand.png b/tests/ref/expand.png
new file mode 100644
index 00000000..fc1f5de9
--- /dev/null
+++ b/tests/ref/expand.png
diff --git a/tests/typ/expand.typ b/tests/typ/expand.typ
new file mode 100644
index 00000000..3b242928
--- /dev/null
+++ b/tests/typ/expand.typ
@@ -0,0 +1,14 @@
+// Test fit/fill expansion.
+
+---
+#let right(body) = align(right, body)
+#let pad(body) = pad(left: 10pt, right: 10pt, body)
+
+// Top-level paragraph fills page, boxed paragraph only when width is fixed.
+L #right[R] \
+#box(width: 50pt)[L #right[R]] \
+#box[L #right[R]] \
+
+// Pad inherits expansion behaviour.
+#pad[PL #right[PR]] \
+#box(pad[PL #right[PR]])
diff --git a/tests/typeset.rs b/tests/typeset.rs
index 232dfa5c..ff0e44bc 100644
--- a/tests/typeset.rs
+++ b/tests/typeset.rs
@@ -20,8 +20,8 @@ use typst::eval::{EvalContext, Scope, Value, ValueArgs, ValueFunc};
 use typst::exec::State;
 use typst::export::pdf;
 use typst::font::FsIndexExt;
-use typst::geom::{Length, Point, Sides, Size, Spec};
-use typst::layout::{Element, Expansion, Fill, Frame, Geometry, Image, Shape};
+use typst::geom::{Length, Point, Sides, Size};
+use typst::layout::{Element, Fill, Frame, Geometry, Image, Shape};
 use typst::library;
 use typst::parse::{LineMap, Scanner};
 use typst::shaping::Shaped;
@@ -202,7 +202,6 @@ fn test_part(
     // large and fit them to match their content.
     let mut state = State::default();
     state.page.size = Size::new(Length::pt(120.0), Length::raw(f64::INFINITY));
-    state.page.expand = Spec::new(Expansion::Fill, Expansion::Fit);
     state.page.margins = Sides::uniform(Some(Length::pt(10.0).into()));
 
     let Pass { output: mut frames, diags } = typeset(env, &src, &scope, state);