Merge #8916

8916: ItemTree pretty-printing r=jonas-schievink a=jonas-schievink

This adds a printer for `ItemTree` contents, and a few tests to ensure that `ItemTree` lowering works like we expect it to. It also adds a new "Debug ItemTree" command that can be used to see the `ItemTree` of the currently open file. The pretty-printed output is usually close enough to Rust syntax that we can even use Rust syntax highlighting.

This is similar to the old `ItemTree` tests we had, but produces significantly more readable output, so these should actually carry their weight.

Co-authored-by: Jonas Schievink <[email protected]>

1 files changed, 11 insertions, 0 deletions

diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 7440e7d29..528270d49 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -1,6 +1,9 @@
 //! A simplified AST that only contains items.
 
 mod lower;
+mod pretty;
+#[cfg(test)]
+mod tests;
 
 use std::{
     any::type_name,
@@ -205,6 +208,10 @@ impl ItemTree {
         }
     }
 
+    pub fn pretty_print(&self) -> String {
+        pretty::print_item_tree(self)
+    }
+
     fn data(&self) -> &ItemTreeData {
         self.data.as_ref().expect("attempted to access data of empty ItemTree")
     }
@@ -776,6 +783,10 @@ impl<T> IdRange<T> {
     fn new(range: Range<Idx<T>>) -> Self {
         Self { range: range.start.into_raw().into()..range.end.into_raw().into(), _p: PhantomData }
     }
+
+    fn is_empty(&self) -> bool {
+        self.range.is_empty()
+    }
 }
 
 impl<T> Iterator for IdRange<T> {