1 files changed, 110 insertions, 98 deletions

diff --git a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
index a8d6355bd..66f274fa7 100644
--- a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -5,7 +5,7 @@ use hir::{Module, ModuleDef, Name, Variant};
 use ide_db::{
     defs::Definition,
     helpers::{
-        insert_use::{insert_use, ImportScope},
+        insert_use::{insert_use, ImportScope, InsertUseConfig},
         mod_path_to_ast,
     },
     search::FileReference,
@@ -13,9 +13,9 @@ use ide_db::{
 };
 use rustc_hash::FxHashSet;
 use syntax::{
-    algo::{find_node_at_offset, SyntaxRewriter},
-    ast::{self, edit::IndentLevel, make, AstNode, NameOwner, VisibilityOwner},
-    SourceFile, SyntaxElement, SyntaxNode, T,
+    algo::find_node_at_offset,
+    ast::{self, make, AstNode, NameOwner, VisibilityOwner},
+    ted, SyntaxNode, T,
 };
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
@@ -62,40 +62,50 @@ pub(crate) fn extract_struct_from_enum_variant(
             let mut visited_modules_set = FxHashSet::default();
             let current_module = enum_hir.module(ctx.db());
             visited_modules_set.insert(current_module);
-            let mut def_rewriter = None;
+            // record file references of the file the def resides in, we only want to swap to the edited file in the builder once
+            let mut def_file_references = None;
             for (file_id, references) in usages {
-                let mut rewriter = SyntaxRewriter::default();
-                let source_file = ctx.sema.parse(file_id);
-                for reference in references {
-                    update_reference(
-                        ctx,
-                        &mut rewriter,
-                        reference,
-                        &source_file,
-                        &enum_module_def,
-                        &variant_hir_name,
-                        &mut visited_modules_set,
-                    );
-                }
                 if file_id == ctx.frange.file_id {
-                    def_rewriter = Some(rewriter);
+                    def_file_references = Some(references);
                     continue;
                 }
                 builder.edit_file(file_id);
-                builder.rewrite(rewriter);
+                let source_file = builder.make_ast_mut(ctx.sema.parse(file_id));
+                let processed = process_references(
+                    ctx,
+                    &mut visited_modules_set,
+                    source_file.syntax(),
+                    &enum_module_def,
+                    &variant_hir_name,
+                    references,
+                );
+                processed.into_iter().for_each(|(path, node, import)| {
+                    apply_references(ctx.config.insert_use, path, node, import)
+                });
             }
-            let mut rewriter = def_rewriter.unwrap_or_default();
-            update_variant(&mut rewriter, &variant);
-            extract_struct_def(
-                &mut rewriter,
-                &enum_ast,
-                variant_name.clone(),
-                &field_list,
-                &variant.parent_enum().syntax().clone().into(),
-                enum_ast.visibility(),
-            );
             builder.edit_file(ctx.frange.file_id);
-            builder.rewrite(rewriter);
+            let source_file = builder.make_ast_mut(ctx.sema.parse(ctx.frange.file_id));
+            let variant = builder.make_ast_mut(variant.clone());
+            if let Some(references) = def_file_references {
+                let processed = process_references(
+                    ctx,
+                    &mut visited_modules_set,
+                    source_file.syntax(),
+                    &enum_module_def,
+                    &variant_hir_name,
+                    references,
+                );
+                processed.into_iter().for_each(|(path, node, import)| {
+                    apply_references(ctx.config.insert_use, path, node, import)
+                });
+            }
+
+            let def = create_struct_def(variant_name.clone(), &field_list, enum_ast.visibility());
+            let start_offset = &variant.parent_enum().syntax().clone();
+            ted::insert_raw(ted::Position::before(start_offset), def.syntax());
+            ted::insert_raw(ted::Position::before(start_offset), &make::tokens::blank_line());
+
+            update_variant(&variant);
         },
     )
 }
@@ -136,34 +146,11 @@ fn existing_definition(db: &RootDatabase, variant_name: &ast::Name, variant: &Va
         .any(|(name, _)| name.to_string() == variant_name.to_string())
 }
 
-fn insert_import(
-    ctx: &AssistContext,
-    rewriter: &mut SyntaxRewriter,
-    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_prefixed(db, *enum_module_def, ctx.config.insert_use.prefix_kind);
-    if let Some(mut mod_path) = mod_path {
-        mod_path.pop_segment();
-        mod_path.push_segment(variant_hir_name.clone());
-        let scope = ImportScope::find_insert_use_container(scope_node, &ctx.sema)?;
-        *rewriter += insert_use(&scope, mod_path_to_ast(&mod_path), ctx.config.insert_use);
-    }
-    Some(())
-}
-
-fn extract_struct_def(
-    rewriter: &mut SyntaxRewriter,
-    enum_: &ast::Enum,
+fn create_struct_def(
     variant_name: ast::Name,
     field_list: &Either<ast::RecordFieldList, ast::TupleFieldList>,
-    start_offset: &SyntaxElement,
     visibility: Option<ast::Visibility>,
-) -> Option<()> {
+) -> ast::Struct {
     let pub_vis = Some(make::visibility_pub());
     let field_list = match field_list {
         Either::Left(field_list) => {
@@ -180,65 +167,90 @@ fn extract_struct_def(
         .into(),
     };
 
-    rewriter.insert_before(
-        start_offset,
-        make::struct_(visibility, variant_name, None, field_list).syntax(),
-    );
-    rewriter.insert_before(start_offset, &make::tokens::blank_line());
-
-    if let indent_level @ 1..=usize::MAX = IndentLevel::from_node(enum_.syntax()).0 as usize {
-        rewriter
-            .insert_before(start_offset, &make::tokens::whitespace(&" ".repeat(4 * indent_level)));
-    }
-    Some(())
+    make::struct_(visibility, variant_name, None, field_list).clone_for_update()
 }
 
-fn update_variant(rewriter: &mut SyntaxRewriter, variant: &ast::Variant) -> Option<()> {
+fn update_variant(variant: &ast::Variant) -> Option<()> {
     let name = variant.name()?;
     let tuple_field = make::tuple_field(None, make::ty(&name.text()));
     let replacement = make::variant(
         name,
         Some(ast::FieldList::TupleFieldList(make::tuple_field_list(iter::once(tuple_field)))),
-    );
-    rewriter.replace(variant.syntax(), replacement.syntax());
+    )
+    .clone_for_update();
+    ted::replace(variant.syntax(), replacement.syntax());
     Some(())
 }
 
-fn update_reference(
+fn apply_references(
+    insert_use_cfg: InsertUseConfig,
+    segment: ast::PathSegment,
+    node: SyntaxNode,
+    import: Option<(ImportScope, hir::ModPath)>,
+) {
+    if let Some((scope, path)) = import {
+        insert_use(&scope, mod_path_to_ast(&path), insert_use_cfg);
+    }
+    ted::insert_raw(
+        ted::Position::before(segment.syntax()),
+        make::path_from_text(&format!("{}", segment)).clone_for_update().syntax(),
+    );
+    ted::insert_raw(ted::Position::before(segment.syntax()), make::token(T!['(']));
+    ted::insert_raw(ted::Position::after(&node), make::token(T![')']));
+}
+
+fn process_references(
     ctx: &AssistContext,
-    rewriter: &mut SyntaxRewriter,
-    reference: FileReference,
-    source_file: &SourceFile,
+    visited_modules: &mut FxHashSet<Module>,
+    source_file: &SyntaxNode,
     enum_module_def: &ModuleDef,
     variant_hir_name: &Name,
-    visited_modules_set: &mut FxHashSet<Module>,
-) -> Option<()> {
+    refs: Vec<FileReference>,
+) -> Vec<(ast::PathSegment, SyntaxNode, Option<(ImportScope, hir::ModPath)>)> {
+    // we have to recollect here eagerly as we are about to edit the tree we need to calculate the changes
+    // and corresponding nodes up front
+    refs.into_iter()
+        .flat_map(|reference| {
+            let (segment, scope_node, module) =
+                reference_to_node(&ctx.sema, source_file, reference)?;
+            if !visited_modules.contains(&module) {
+                let mod_path = module.find_use_path_prefixed(
+                    ctx.sema.db,
+                    *enum_module_def,
+                    ctx.config.insert_use.prefix_kind,
+                );
+                if let Some(mut mod_path) = mod_path {
+                    mod_path.pop_segment();
+                    mod_path.push_segment(variant_hir_name.clone());
+                    let scope = ImportScope::find_insert_use_container(&scope_node)?;
+                    visited_modules.insert(module);
+                    return Some((segment, scope_node, Some((scope, mod_path))));
+                }
+            }
+            Some((segment, scope_node, None))
+        })
+        .collect()
+}
+
+fn reference_to_node(
+    sema: &hir::Semantics<RootDatabase>,
+    source_file: &SyntaxNode,
+    reference: FileReference,
+) -> Option<(ast::PathSegment, SyntaxNode, hir::Module)> {
     let offset = reference.range.start();
-    let (segment, expr) = if let Some(path_expr) =
-        find_node_at_offset::<ast::PathExpr>(source_file.syntax(), offset)
-    {
+    if let Some(path_expr) = find_node_at_offset::<ast::PathExpr>(source_file, offset) {
         // tuple variant
-        (path_expr.path()?.segment()?, path_expr.syntax().parent()?)
-    } else if let Some(record_expr) =
-        find_node_at_offset::<ast::RecordExpr>(source_file.syntax(), offset)
-    {
+        Some((path_expr.path()?.segment()?, path_expr.syntax().parent()?))
+    } else if let Some(record_expr) = find_node_at_offset::<ast::RecordExpr>(source_file, offset) {
         // record variant
-        (record_expr.path()?.segment()?, record_expr.syntax().clone())
+        Some((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, &expr, &module, enum_module_def, variant_hir_name).is_some()
-        {
-            visited_modules_set.insert(module);
-        }
+        None
     }
-    rewriter.insert_after(segment.syntax(), &make::token(T!['(']));
-    rewriter.insert_after(segment.syntax(), segment.syntax());
-    rewriter.insert_after(&expr, &make::token(T![')']));
-    Some(())
+    .and_then(|(segment, expr)| {
+        let module = sema.scope(&expr).module()?;
+        Some((segment, expr, module))
+    })
 }
 
 #[cfg(test)]
@@ -345,7 +357,7 @@ mod my_mod {
 
         pub struct MyField(pub u8, pub u8);
 
-        pub enum MyEnum {
+pub enum MyEnum {
             MyField(MyField),
         }
     }