1 files changed, 68 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/goto_type_definition.rs b/crates/ra_ide_api/src/goto_type_definition.rs
new file mode 100644
index 000000000..b6a3c1c3a
--- /dev/null
+++ b/crates/ra_ide_api/src/goto_type_definition.rs
@@ -0,0 +1,68 @@
+use ra_db::SourceDatabase;
+use ra_syntax::{
+    AstNode, ast,
+    algo::find_token_at_offset
+};
+
+use crate::{FilePosition, NavigationTarget, db::RootDatabase, RangeInfo};
+
+pub(crate) fn goto_type_definition(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    let file = db.parse(position.file_id);
+
+    let node = find_token_at_offset(file.syntax(), position.offset).find_map(|token| {
+        token
+            .parent()
+            .ancestors()
+            .find(|n| ast::Expr::cast(*n).is_some() || ast::Pat::cast(*n).is_some())
+    })?;
+
+    let analyzer = hir::SourceAnalyzer::new(db, position.file_id, node, None);
+
+    let ty: hir::Ty = if let Some(ty) = ast::Expr::cast(node).and_then(|e| analyzer.type_of(db, e))
+    {
+        ty
+    } else if let Some(ty) = ast::Pat::cast(node).and_then(|p| analyzer.type_of_pat(db, p)) {
+        ty
+    } else {
+        return None;
+    };
+
+    if let Some((adt_def, _)) = ty.as_adt() {
+        let nav = NavigationTarget::from_adt_def(db, adt_def);
+        return Some(RangeInfo::new(node.range(), vec![nav]));
+    };
+
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check_goto(fixture: &str, expected: &str) {
+        let (analysis, pos) = analysis_and_position(fixture);
+
+        let mut navs = analysis.goto_type_definition(pos).unwrap().unwrap().info;
+        assert_eq!(navs.len(), 1);
+        let nav = navs.pop().unwrap();
+        nav.assert_match(expected);
+    }
+
+    #[test]
+    fn goto_type_definition_works_simple() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            fn foo() {
+                let f: Foo;
+                f<|>
+            }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+    }
+}