Merge pull request #19255 from geetanshjuneja/master

Add children modules feature

crates/ide/src/children_modules.rs

@@ -0,0 +1,123 @@
+use hir::Semantics;
+use ide_db::{FilePosition, RootDatabase};
+use syntax::{
+    algo::find_node_at_offset,
+    ast::{self, AstNode},
+};
+
+use crate::NavigationTarget;
+
+// Feature: Children Modules
+//
+// Navigates to the children modules of the current module.
+//
+// | Editor  | Action Name |
+// |---------|-------------|
+// | VS Code | **rust-analyzer: Locate children modules** |
+
+/// This returns `Vec` because a module may be included from several places.
+pub(crate) fn children_modules(db: &RootDatabase, position: FilePosition) -> Vec<NavigationTarget> {
+    let sema = Semantics::new(db);
+    let source_file = sema.parse_guess_edition(position.file_id);
+    // First go to the parent module which contains the cursor
+    let module = find_node_at_offset::<ast::Module>(source_file.syntax(), position.offset);
+
+    match module {
+        Some(module) => {
+            // Return all the children module inside the ItemList of the parent module
+            sema.to_def(&module)
+                .into_iter()
+                .flat_map(|module| module.children(db))
+                .map(|module| NavigationTarget::from_module_to_decl(db, module).call_site())
+                .collect()
+        }
+        None => {
+            // Return all the children module inside the source file
+            sema.file_to_module_defs(position.file_id)
+                .flat_map(|module| module.children(db))
+                .map(|module| NavigationTarget::from_module_to_decl(db, module).call_site())
+                .collect()
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use ide_db::FileRange;
+
+    use crate::fixture;
+
+    fn check_children_module(#[rust_analyzer::rust_fixture] ra_fixture: &str) {
+        let (analysis, position, expected) = fixture::annotations(ra_fixture);
+        let navs = analysis.children_modules(position).unwrap();
+        let navs = navs
+            .iter()
+            .map(|nav| FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() })
+            .collect::<Vec<_>>();
+        assert_eq!(expected.into_iter().map(|(fr, _)| fr).collect::<Vec<_>>(), navs);
+    }
+
+    #[test]
+    fn test_resolve_children_module() {
+        check_children_module(
+            r#"
+//- /lib.rs
+$0
+mod foo;
+  //^^^
+
+//- /foo.rs
+// empty
+"#,
+        );
+    }
+
+    #[test]
+    fn test_resolve_children_module_on_module_decl() {
+        check_children_module(
+            r#"
+//- /lib.rs
+mod $0foo;
+//- /foo.rs
+mod bar;
+  //^^^
+
+//- /foo/bar.rs
+// empty
+"#,
+        );
+    }
+
+    #[test]
+    fn test_resolve_children_module_for_inline() {
+        check_children_module(
+            r#"
+//- /lib.rs
+mod foo {
+    mod $0bar {
+        mod baz {}
+    }     //^^^
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_resolve_multi_child_module() {
+        check_children_module(
+            r#"
+//- /main.rs
+$0
+mod foo;
+  //^^^
+mod bar;
+  //^^^
+//- /foo.rs
+// empty
+
+//- /bar.rs
+// empty
+"#,
+        );
+    }
+}

crates/ide/src/lib.rs

@@ -20,6 +20,7 @@ mod navigation_target;
 
 mod annotations;
 mod call_hierarchy;
+mod children_modules;
 mod doc_links;
 mod expand_macro;
 mod extend_selection;
@@ -605,6 +606,11 @@ impl Analysis {
         self.with_db(|db| parent_module::parent_module(db, position))
     }
 
+    /// Returns vec of `mod name;` declaration which are created by the current module.
+    pub fn children_modules(&self, position: FilePosition) -> Cancellable<Vec<NavigationTarget>> {
+        self.with_db(|db| children_modules::children_modules(db, position))
+    }
+
     /// Returns crates that this file belongs to.
     pub fn crates_for(&self, file_id: FileId) -> Cancellable<Vec<Crate>> {
         self.with_db(|db| parent_module::crates_for(db, file_id))