fix: improve indent for insert_use e.g complete import

crates/ide-db/src/imports/insert_use.rs

@@ -436,6 +436,9 @@ fn insert_use_with_editor_(
             Some((tree, node))
         });
 
+    let newline =
+        |nl, node: &SyntaxNode| make.whitespace(&format!("{nl}{}", IndentLevel::from_node(node)));
+
     if group_imports {
         // Iterator that discards anything that's not in the required grouping
         // This implementation allows the user to rearrange their import groups as this only takes the first group that fits
@@ -455,16 +458,16 @@ fn insert_use_with_editor_(
             cov_mark::hit!(insert_group);
             // insert our import before that element
             return syntax_editor.insert_all(
-                Position::before(node),
-                vec![use_item.syntax().clone().into(), make.whitespace("\n").into()],
+                Position::before(&node),
+                vec![use_item.syntax().clone().into(), newline("\n", &node).into()],
             );
         }
         if let Some(node) = last {
             cov_mark::hit!(insert_group_last);
             // there is no element after our new import, so append it to the end of the group
             return syntax_editor.insert_all(
-                Position::after(node),
-                vec![make.whitespace("\n").into(), use_item.syntax().clone().into()],
+                Position::after(&node),
+                vec![newline("\n", &node).into(), use_item.syntax().clone().into()],
             );
         }
 
@@ -479,7 +482,7 @@ fn insert_use_with_editor_(
             cov_mark::hit!(insert_group_new_group);
             syntax_editor.insert_all(
                 Position::before(&node),
-                vec![use_item.syntax().clone().into(), make.whitespace("\n\n").into()],
+                vec![use_item.syntax().clone().into(), newline("\n\n", &node).into()],
             );
             return;
         }
@@ -488,7 +491,7 @@ fn insert_use_with_editor_(
             cov_mark::hit!(insert_group_no_group);
             syntax_editor.insert_all(
                 Position::after(&node),
-                vec![make.whitespace("\n\n").into(), use_item.syntax().clone().into()],
+                vec![newline("\n\n", &node).into(), use_item.syntax().clone().into()],
             );
             return;
         }
@@ -497,8 +500,8 @@ fn insert_use_with_editor_(
         if let Some((_, node)) = path_node_iter.last() {
             cov_mark::hit!(insert_no_grouping_last);
             syntax_editor.insert_all(
-                Position::after(node),
-                vec![make.whitespace("\n").into(), use_item.syntax().clone().into()],
+                Position::after(&node),
+                vec![newline("\n", &node).into(), use_item.syntax().clone().into()],
             );
             return;
         }
@@ -545,14 +548,22 @@ fn insert_use_with_editor_(
     } else {
         match l_curly {
             Some(b) => {
-                cov_mark::hit!(insert_empty_module);
+                let close_ws = if let Some(next) = syntax::algo::next_non_trivia_token(b.clone())
+                    && next.kind() == SyntaxKind::R_CURLY
+                {
+                    cov_mark::hit!(insert_empty_module);
+                    newline("\n", scope_syntax)
+                } else {
+                    cov_mark::hit!(insert_first_of_module);
+                    make.whitespace("\n")
+                };
                 let indent = IndentLevel::from_node(scope_syntax) + 1;
                 syntax_editor.insert_all(
                     Position::after(&b),
                     vec![
                         make.whitespace(&format!("\n{indent}")).into(),
                         use_item.syntax().clone().into(),
-                        make.whitespace("\n").into(),
+                        close_ws.into(),
                     ],
                 );
             }

crates/ide-db/src/imports/insert_use/tests.rs

@@ -22,6 +22,83 @@ struct Struct;
     );
 }
 
+#[test]
+fn insert_in_module_indent() {
+    cov_mark::check!(insert_group);
+    check(
+        "foo::bar",
+        r#"
+mod tests {
+    $0use xxx;
+}
+"#,
+        r#"
+mod tests {
+    use foo::bar;
+    use xxx;
+}
+"#,
+        ImportGranularity::Crate,
+    );
+
+    cov_mark::check!(insert_group_last);
+    check(
+        "foo::bar",
+        r#"
+mod tests {
+    $0use aaa;
+}
+"#,
+        r#"
+mod tests {
+    use aaa;
+    use foo::bar;
+}
+"#,
+        ImportGranularity::Crate,
+    );
+
+    cov_mark::check!(insert_group_new_group);
+    check_none(
+        "std::fmt",
+        r#"
+mod tests {
+    $0use foo::bar::A;
+    use foo::bar::D;
+}
+"#,
+        r#"
+mod tests {
+    use std::fmt;
+
+    use foo::bar::A;
+    use foo::bar::D;
+}
+"#,
+    );
+
+    cov_mark::check!(insert_first_of_module);
+    check_none(
+        "baz::Baz",
+        r#"
+mod foo {
+    mod bar {
+        const _: Baz$0 = ();
+    }
+}
+"#,
+        r#"
+mod foo {
+    mod bar {
+        use baz::Baz;
+
+        const _: Baz = ();
+    }
+}
+"#,
+    );
+}
+
 #[test]
 fn respects_cfg_attr_fn_body() {
     check(
@@ -473,11 +550,15 @@ fn insert_empty_module() {
     check(
         "foo::bar",
         r"
-mod x {$0}
+mod indent {
+    mod x {$0}
+}
 ",
         r"
-mod x {
-    use foo::bar;
+mod indent {
+    mod x {
+        use foo::bar;
+    }
 }
 ",
         ImportGranularity::Item,
@@ -549,6 +630,7 @@ fn main() {}",
 
 #[test]
 fn inserts_after_single_line_inner_comments() {
+    cov_mark::check_count!(insert_empty_inner_attr, 2);
     check_none(
         "foo::bar::Baz",
         "//! Single line inner comments do not allow any code before them.",