Merge #3121

3121: Do not add imports before inner attributes r=matklad a=SomeoneToIgnore

Current `insert_use_statement` function adds imports before inner attributes which results in compiler errors:
<img width="1440" alt="image" src="https://user-images.githubusercontent.com/2690773/74344019-a3749500-4db4-11ea-9d88-f71e903e795a.png">


Co-authored-by: Kirill Bulatov <mail4score@gmail.com>

crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs

@@ -431,7 +431,12 @@ fn best_action_for_target(
                 .find(|n| n.text_range().start() < anchor.text_range().start())
                 .or_else(|| Some(anchor));
 
-            ImportAction::add_new_use(anchor, false)
+            let add_after_anchor = anchor
+                .clone()
+                .and_then(ast::Attr::cast)
+                .map(|attr| attr.kind() == ast::AttrKind::Inner)
+                .unwrap_or(false);
+            ImportAction::add_new_use(anchor, add_after_anchor)
         }
     }
 }
@@ -958,6 +963,28 @@ mod foo {
 
         Debug<|>
     }
+}
+    ",
+        );
+    }
+
+    #[test]
+    fn inserts_imports_after_inner_attributes() {
+        check_assist(
+            replace_qualified_name_with_use,
+            "
+#![allow(dead_code)]
+
+fn main() {
+    std::fmt::Debug<|>
+}
+    ",
+            "
+#![allow(dead_code)]
+use std::fmt::Debug;
+
+fn main() {
+    Debug<|>
 }
     ",
         );

crates/ra_syntax/src/ast.rs

@@ -18,8 +18,8 @@ use crate::{
 pub use self::{
     expr_extensions::{ArrayExprKind, BinOp, ElseBranch, LiteralKind, PrefixOp, RangeOp},
     extensions::{
-        FieldKind, PathSegmentKind, SelfParamKind, SlicePatComponents, StructKind, TypeBoundKind,
+        AttrKind, FieldKind, PathSegmentKind, SelfParamKind, SlicePatComponents, StructKind,
-        VisibilityKind,
+        TypeBoundKind, VisibilityKind,
     },
     generated::*,
     tokens::*,
@@ -217,10 +217,7 @@ fn test_doc_comment_multi_line_block_strips_suffix() {
 #[test]
 fn test_comments_preserve_trailing_whitespace() {
     let file = SourceFile::parse(
-        r#"
+        "\n/// Representation of a Realm.   \n/// In the specification these are called Realm Records.\nstruct Realm {}",
-/// Representation of a Realm.   
-/// In the specification these are called Realm Records.
-struct Realm {}"#,
     )
     .ok()
     .unwrap();

crates/ra_syntax/src/ast/extensions.rs

@@ -37,6 +37,12 @@ fn text_of_first_token(node: &SyntaxNode) -> &SmolStr {
     node.green().children().next().and_then(|it| it.into_token()).unwrap().text()
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AttrKind {
+    Inner,
+    Outer,
+}
+
 impl ast::Attr {
     pub fn as_simple_atom(&self) -> Option<SmolStr> {
         match self.input() {
@@ -71,6 +77,18 @@ impl ast::Attr {
             _ => None,
         }
     }
+
+    pub fn kind(&self) -> AttrKind {
+        let first_token = self.syntax().first_token();
+        let first_token_kind = first_token.as_ref().map(SyntaxToken::kind);
+        let second_token_kind =
+            first_token.and_then(|token| token.next_token()).as_ref().map(SyntaxToken::kind);
+
+        match (first_token_kind, second_token_kind) {
+            (Some(SyntaxKind::POUND), Some(SyntaxKind::EXCL)) => AttrKind::Inner,
+            _ => AttrKind::Outer,
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]