rust-analyzer/crates/ide/src/view_item_tree.rs

use hir::{db::DefDatabase, Semantics};
use ide_db::{FileId, RootDatabase};
use span::EditionedFileId;

// 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 {
    let sema = Semantics::new(db);
    let file_id = sema
        .attach_first_edition(file_id)
        .unwrap_or_else(|| EditionedFileId::current_edition(file_id));
    db.file_item_tree(file_id.into()).pretty_print(db, file_id.edition())
}