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]>

2 files changed, 21 insertions, 0 deletions

diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index f4b90db3a..ff2a54117 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -50,6 +50,7 @@ mod typing;
 mod markdown_remove;
 mod doc_links;
 mod view_crate_graph;
+mod view_item_tree;
 
 use std::sync::Arc;
 
@@ -288,6 +289,10 @@ impl Analysis {
         self.with_db(|db| view_hir::view_hir(&db, position))
     }
 
+    pub fn view_item_tree(&self, file_id: FileId) -> Cancelable<String> {
+        self.with_db(|db| view_item_tree::view_item_tree(&db, file_id))
+    }
+
     /// Renders the crate graph to GraphViz "dot" syntax.
     pub fn view_crate_graph(&self) -> Cancelable<Result<String, String>> {
         self.with_db(|db| view_crate_graph::view_crate_graph(&db))
diff --git a/crates/ide/src/view_item_tree.rs b/crates/ide/src/view_item_tree.rs
new file mode 100644
index 000000000..3dc03085d
--- /dev/null
+++ b/crates/ide/src/view_item_tree.rs
@@ -0,0 +1,16 @@
+use hir::db::DefDatabase;
+use ide_db::base_db::FileId;
+use ide_db::RootDatabase;
+
+// Feature: Debug ItemTree
+//
+// Displays the ItemTree of the currently open file, for debugging.
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Debug ItemTree**
+// |===
+pub(crate) fn view_item_tree(db: &RootDatabase, file_id: FileId) -> String {
+    db.file_item_tree(file_id.into()).pretty_print()
+}