4 files changed, 262 insertions, 49 deletions

diff --git a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
index 84662d832..067afabf2 100644
--- a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -5,10 +5,9 @@ use hir::{AsName, EnumVariant, Module, ModuleDef, Name};
 use ide_db::{defs::Definition, search::Reference, RootDatabase};
 use rustc_hash::{FxHashMap, FxHashSet};
 use syntax::{
-    algo::find_node_at_offset,
-    algo::SyntaxRewriter,
-    ast::{self, edit::IndentLevel, make, ArgListOwner, AstNode, NameOwner, VisibilityOwner},
-    SourceFile, SyntaxElement,
+    algo::{find_node_at_offset, SyntaxRewriter},
+    ast::{self, edit::IndentLevel, make, AstNode, NameOwner, VisibilityOwner},
+    SourceFile, SyntaxElement, SyntaxNode, T,
 };
 
 use crate::{
@@ -130,17 +129,21 @@ fn existing_definition(db: &RootDatabase, variant_name: &ast::Name, variant: &En
 fn insert_import(
     ctx: &AssistContext,
     rewriter: &mut SyntaxRewriter,
-    path: &ast::PathExpr,
+    scope_node: &SyntaxNode,
     module: &Module,
     enum_module_def: &ModuleDef,
     variant_hir_name: &Name,
 ) -> Option<()> {
     let db = ctx.db();
-    let mod_path = module.find_use_path(db, enum_module_def.clone());
+    let mod_path = module.find_use_path_prefixed(
+        db,
+        enum_module_def.clone(),
+        ctx.config.insert_use.prefix_kind,
+    );
     if let Some(mut mod_path) = mod_path {
         mod_path.segments.pop();
         mod_path.segments.push(variant_hir_name.clone());
-        let scope = ImportScope::find_insert_use_container(path.syntax(), ctx)?;
+        let scope = ImportScope::find_insert_use_container(scope_node, ctx)?;
 
         *rewriter += insert_use(&scope, mod_path_to_ast(&mod_path), ctx.config.insert_use.merge);
     }
@@ -204,27 +207,31 @@ fn update_reference(
     variant_hir_name: &Name,
     visited_modules_set: &mut FxHashSet<Module>,
 ) -> Option<()> {
-    let path_expr: ast::PathExpr = find_node_at_offset::<ast::PathExpr>(
-        source_file.syntax(),
-        reference.file_range.range.start(),
-    )?;
-    let call = path_expr.syntax().parent().and_then(ast::CallExpr::cast)?;
-    let list = call.arg_list()?;
-    let segment = path_expr.path()?.segment()?;
-    let module = ctx.sema.scope(&path_expr.syntax()).module()?;
+    let offset = reference.file_range.range.start();
+    let (segment, expr) = if let Some(path_expr) =
+        find_node_at_offset::<ast::PathExpr>(source_file.syntax(), offset)
+    {
+        // tuple variant
+        (path_expr.path()?.segment()?, path_expr.syntax().parent()?.clone())
+    } else if let Some(record_expr) =
+        find_node_at_offset::<ast::RecordExpr>(source_file.syntax(), offset)
+    {
+        // record variant
+        (record_expr.path()?.segment()?, record_expr.syntax().clone())
+    } else {
+        return None;
+    };
+
+    let module = ctx.sema.scope(&expr).module()?;
     if !visited_modules_set.contains(&module) {
-        if insert_import(ctx, rewriter, &path_expr, &module, enum_module_def, variant_hir_name)
-            .is_some()
+        if insert_import(ctx, rewriter, &expr, &module, enum_module_def, variant_hir_name).is_some()
         {
             visited_modules_set.insert(module);
         }
     }
-
-    let lparen = syntax::SyntaxElement::from(list.l_paren_token()?);
-    let rparen = syntax::SyntaxElement::from(list.r_paren_token()?);
-    rewriter.insert_after(&lparen, segment.syntax());
-    rewriter.insert_after(&lparen, &lparen);
-    rewriter.insert_before(&rparen, &rparen);
+    rewriter.insert_after(segment.syntax(), &make::token(T!['(']));
+    rewriter.insert_after(segment.syntax(), segment.syntax());
+    rewriter.insert_after(&expr, &make::token(T![')']));
     Some(())
 }
 
@@ -320,7 +327,7 @@ fn another_fn() {
             r#"use my_mod::my_other_mod::MyField;
 
 mod my_mod {
-    use my_other_mod::MyField;
+    use self::my_other_mod::MyField;
 
     fn another_fn() {
         let m = my_other_mod::MyEnum::MyField(MyField(1, 1));
@@ -346,6 +353,33 @@ fn another_fn() {
     }
 
     #[test]
+    fn extract_record_fix_references() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            r#"
+enum E {
+    <|>V { i: i32, j: i32 }
+}
+
+fn f() {
+    let e = E::V { i: 9, j: 2 };
+}
+"#,
+            r#"
+struct V{ pub i: i32, pub j: i32 }
+
+enum E {
+    V(V)
+}
+
+fn f() {
+    let e = E::V(V { i: 9, j: 2 });
+}
+"#,
+        )
+    }
+
+    #[test]
     fn test_several_files() {
         check_assist(
             extract_struct_from_enum_variant,
@@ -372,9 +406,7 @@ enum E {
 mod foo;
 
 //- /foo.rs
-use V;
-
-use crate::E;
+use crate::{E, V};
 fn f() {
     let e = E::V(V(9, 2));
 }
@@ -384,7 +416,6 @@ fn f() {
 
     #[test]
     fn test_several_files_record() {
-        // FIXME: this should fix the usage as well!
         check_assist(
             extract_struct_from_enum_variant,
             r#"
@@ -401,6 +432,7 @@ fn f() {
 }
 "#,
             r#"
+//- /main.rs
 struct V{ pub i: i32, pub j: i32 }
 
 enum E {
@@ -408,10 +440,42 @@ enum E {
 }
 mod foo;
 
+//- /foo.rs
+use crate::{E, V};
+fn f() {
+    let e = E::V(V { i: 9, j: 2 });
+}
 "#,
         )
     }
 
+    #[test]
+    fn test_extract_struct_record_nested_call_exp() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            r#"
+enum A { <|>One { a: u32, b: u32 } }
+
+struct B(A);
+
+fn foo() {
+    let _ = B(A::One { a: 1, b: 2 });
+}
+"#,
+            r#"
+struct One{ pub a: u32, pub b: u32 }
+
+enum A { One(One) }
+
+struct B(A);
+
+fn foo() {
+    let _ = B(A::One(One { a: 1, b: 2 }));
+}
+"#,
+        );
+    }
+
     fn check_not_applicable(ra_fixture: &str) {
         let fixture =
             format!("//- /main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
diff --git a/crates/assists/src/handlers/remove_unused_param.rs b/crates/assists/src/handlers/remove_unused_param.rs
index 5fccca54b..1ff5e92b0 100644
--- a/crates/assists/src/handlers/remove_unused_param.rs
+++ b/crates/assists/src/handlers/remove_unused_param.rs
@@ -73,7 +73,8 @@ fn process_usage(
     let source_file = ctx.sema.parse(usage.file_range.file_id);
     let call_expr: ast::CallExpr =
         find_node_at_range(source_file.syntax(), usage.file_range.range)?;
-    if call_expr.expr()?.syntax().text_range() != usage.file_range.range {
+    let call_expr_range = call_expr.expr()?.syntax().text_range();
+    if !call_expr_range.contains_range(usage.file_range.range) {
         return None;
     }
     let arg = call_expr.arg_list()?.args().nth(arg_to_remove)?;
@@ -118,6 +119,53 @@ fn b() { foo(9, ) }
     }
 
     #[test]
+    fn remove_unused_qualified_call() {
+        check_assist(
+            remove_unused_param,
+            r#"
+mod bar { pub fn foo(x: i32, <|>y: i32) { x; } }
+fn b() { bar::foo(9, 2) }
+"#,
+            r#"
+mod bar { pub fn foo(x: i32) { x; } }
+fn b() { bar::foo(9) }
+"#,
+        );
+    }
+
+    #[test]
+    fn remove_unused_turbofished_func() {
+        check_assist(
+            remove_unused_param,
+            r#"
+pub fn foo<T>(x: T, <|>y: i32) { x; }
+fn b() { foo::<i32>(9, 2) }
+"#,
+            r#"
+pub fn foo<T>(x: T) { x; }
+fn b() { foo::<i32>(9) }
+"#,
+        );
+    }
+
+    #[test]
+    fn remove_unused_generic_unused_param_func() {
+        check_assist(
+            remove_unused_param,
+            r#"
+pub fn foo<T>(x: i32, <|>y: T) { x; }
+fn b() { foo::<i32>(9, 2) }
+fn b2() { foo(9, 2) }
+"#,
+            r#"
+pub fn foo<T>(x: i32) { x; }
+fn b() { foo::<i32>(9) }
+fn b2() { foo(9) }
+"#,
+        );
+    }
+
+    #[test]
     fn keep_used() {
         mark::check!(keep_used);
         check_assist_not_applicable(
@@ -128,4 +176,37 @@ fn main() { foo(9, 2) }
 "#,
         );
     }
+
+    #[test]
+    fn remove_across_files() {
+        check_assist(
+            remove_unused_param,
+            r#"
+//- /main.rs
+fn foo(x: i32, <|>y: i32) { x; }
+
+mod foo;
+
+//- /foo.rs
+use super::foo;
+
+fn bar() {
+    let _ = foo(1, 2);
+}
+"#,
+            r#"
+//- /main.rs
+fn foo(x: i32) { x; }
+
+mod foo;
+
+//- /foo.rs
+use super::foo;
+
+fn bar() {
+    let _ = foo(1);
+}
+"#,
+        )
+    }
 }
diff --git a/crates/assists/src/utils.rs b/crates/assists/src/utils.rs
index 7071fe96b..7bd338e99 100644
--- a/crates/assists/src/utils.rs
+++ b/crates/assists/src/utils.rs
@@ -257,6 +257,12 @@ pub mod convert {
     }
 }
 
+pub mod default {
+    pub trait Default {
+       fn default() -> Self;
+    }
+}
+
 pub mod iter {
     pub use self::traits::{collect::IntoIterator, iterator::Iterator};
     mod traits {
@@ -327,7 +333,7 @@ pub mod option {
 }
 
 pub mod prelude {
-    pub use crate::{convert::From, iter::{IntoIterator, Iterator}, option::Option::{self, *}};
+    pub use crate::{convert::From, iter::{IntoIterator, Iterator}, option::Option::{self, *}, default::Default};
 }
 #[prelude_import]
 pub use prelude::*;
@@ -345,6 +351,10 @@ pub use prelude::*;
         self.find_enum("core:option:Option")
     }
 
+    pub fn core_default_Default(&self) -> Option<Trait> {
+        self.find_trait("core:default:Default")
+    }
+
     pub fn core_iter_Iterator(&self) -> Option<Trait> {
         self.find_trait("core:iter:traits:iterator:Iterator")
     }
diff --git a/crates/assists/src/utils/insert_use.rs b/crates/assists/src/utils/insert_use.rs
index 84a0dffdd..af3fc96b6 100644
--- a/crates/assists/src/utils/insert_use.rs
+++ b/crates/assists/src/utils/insert_use.rs
@@ -9,7 +9,7 @@ use syntax::{
         edit::{AstNodeEdit, IndentLevel},
         make, AstNode, PathSegmentKind, VisibilityOwner,
     },
-    InsertPosition, SyntaxElement, SyntaxNode,
+    AstToken, InsertPosition, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxToken,
 };
 use test_utils::mark;
 
@@ -63,27 +63,30 @@ impl ImportScope {
         }
     }
 
-    fn insert_pos_after_inner_attribute(&self) -> (InsertPosition<SyntaxElement>, AddBlankLine) {
-        // check if the scope has inner attributes, we dont want to insert in front of them
-        match self
-            .as_syntax_node()
-            .children()
-            // no flat_map here cause we want to short circuit the iterator
-            .map(ast::Attr::cast)
-            .take_while(|attr| {
-                attr.as_ref().map(|attr| attr.kind() == ast::AttrKind::Inner).unwrap_or(false)
+    fn insert_pos_after_last_inner_element(&self) -> (InsertPosition<SyntaxElement>, AddBlankLine) {
+        self.as_syntax_node()
+            .children_with_tokens()
+            .filter(|child| match child {
+                NodeOrToken::Node(node) => is_inner_attribute(node.clone()),
+                NodeOrToken::Token(token) => is_inner_comment(token.clone()),
             })
             .last()
-            .flatten()
-        {
-            Some(attr) => {
-                (InsertPosition::After(attr.syntax().clone().into()), AddBlankLine::BeforeTwice)
-            }
-            None => self.first_insert_pos(),
-        }
+            .map(|last_inner_element| {
+                (InsertPosition::After(last_inner_element.into()), AddBlankLine::BeforeTwice)
+            })
+            .unwrap_or_else(|| self.first_insert_pos())
     }
 }
 
+fn is_inner_attribute(node: SyntaxNode) -> bool {
+    ast::Attr::cast(node).map(|attr| attr.kind()) == Some(ast::AttrKind::Inner)
+}
+
+fn is_inner_comment(token: SyntaxToken) -> bool {
+    ast::Comment::cast(token).and_then(|comment| comment.kind().doc)
+        == Some(ast::CommentPlacement::Inner)
+}
+
 /// Insert an import path into the given file/node. A `merge` value of none indicates that no import merging is allowed to occur.
 pub(crate) fn insert_use<'a>(
     scope: &ImportScope,
@@ -558,7 +561,7 @@ fn find_insert_position(
                             (InsertPosition::After(node.into()), AddBlankLine::BeforeTwice)
                         }
                         // there are no imports in this file at all
-                        None => scope.insert_pos_after_inner_attribute(),
+                        None => scope.insert_pos_after_last_inner_element(),
                     },
                 }
             }
@@ -830,12 +833,67 @@ use foo::bar;",
             "foo::bar",
             r"#![allow(unused_imports)]
 
+#![no_std]
 fn main() {}",
             r"#![allow(unused_imports)]
 
-use foo::bar;
+#![no_std]
 
+use foo::bar;
 fn main() {}",
+        );
+    }
+
+    #[test]
+    fn inserts_after_single_line_inner_comments() {
+        check_none(
+            "foo::bar::Baz",
+            "//! Single line inner comments do not allow any code before them.",
+            r#"//! Single line inner comments do not allow any code before them.
+
+use foo::bar::Baz;"#,
+        );
+    }
+
+    #[test]
+    fn inserts_after_multiline_inner_comments() {
+        check_none(
+            "foo::bar::Baz",
+            r#"/*! Multiline inner comments do not allow any code before them. */
+
+/*! Still an inner comment, cannot place any code before. */
+fn main() {}"#,
+            r#"/*! Multiline inner comments do not allow any code before them. */
+
+/*! Still an inner comment, cannot place any code before. */
+
+use foo::bar::Baz;
+fn main() {}"#,
+        )
+    }
+
+    #[test]
+    fn inserts_after_all_inner_items() {
+        check_none(
+            "foo::bar::Baz",
+            r#"#![allow(unused_imports)]
+/*! Multiline line comment 2 */
+
+
+//! Single line comment 1
+#![no_std]
+//! Single line comment 2
+fn main() {}"#,
+            r#"#![allow(unused_imports)]
+/*! Multiline line comment 2 */
+
+
+//! Single line comment 1
+#![no_std]
+//! Single line comment 2
+
+use foo::bar::Baz;
+fn main() {}"#,
         )
     }