Migrate merge_imports Assist to Use SyntaxFactory

crates/ide-assists/src/handlers/merge_imports.rs

@@ -6,8 +6,10 @@ use ide_db::imports::{
 use itertools::Itertools;
 use syntax::{
     algo::neighbor,
-    ast::{self, edit_in_place::Removable},
-    match_ast, ted, AstNode, SyntaxElement, SyntaxNode,
+    ast::{self, syntax_factory::SyntaxFactory},
+    match_ast,
+    syntax_editor::edits::Removable,
+    AstNode, SyntaxElement, SyntaxNode,
 };
 
 use crate::{
@@ -68,24 +70,30 @@ pub(crate) fn merge_imports(acc: &mut Assists, ctx: &AssistContext<'_>) -> Optio
         (selection_range, edits?)
     };
 
+    let parent_node = match ctx.covering_element() {
+        SyntaxElement::Node(n) => n,
+        SyntaxElement::Token(t) => t.parent()?,
+    };
+    let make = SyntaxFactory::new();
+
     acc.add(
         AssistId("merge_imports", AssistKind::RefactorRewrite),
         "Merge imports",
         target,
         |builder| {
-            let edits_mut: Vec<Edit> = edits
-                .into_iter()
-                .map(|it| match it {
-                    Remove(Either::Left(it)) => Remove(Either::Left(builder.make_mut(it))),
-                    Remove(Either::Right(it)) => Remove(Either::Right(builder.make_mut(it))),
-                    Replace(old, new) => Replace(builder.make_syntax_mut(old), new),
-                })
-                .collect();
-            for edit in edits_mut {
+            let mut editor = builder.make_editor(&parent_node);
+            for edit in edits {
                 match edit {
-                    Remove(it) => it.as_ref().either(Removable::remove, Removable::remove),
+                    Remove(it) => {
+                        let node = it.as_ref();
+                        if let Some(left) = node.left() {
+                            left.remove(&mut editor);
+                        } else if let Some(right) = node.right() {
+                            right.remove(&mut editor);
+                        }
+                    }
                     Replace(old, new) => {
-                        ted::replace(old, &new);
+                        editor.replace(old, &new);
 
                         // If there's a selection and we're replacing a use tree in a tree list,
                         // normalize the parent use tree if it only contains the merged subtree.
@@ -109,12 +117,14 @@ pub(crate) fn merge_imports(acc: &mut Assists, ctx: &AssistContext<'_>) -> Optio
                                 });
                             if let Some((old_tree, new_tree)) = normalized_use_tree {
                                 cov_mark::hit!(replace_parent_with_normalized_use_tree);
-                                ted::replace(old_tree.syntax(), new_tree.syntax());
+                                editor.replace(old_tree.syntax(), new_tree.syntax());
                             }
                         }
                     }
                 }
             }
+            editor.add_mappings(make.finish_with_mappings());
+            builder.add_file_edits(ctx.file_id(), editor);
         },
     )
 }

crates/syntax/src/ast/syntax_factory/constructors.rs

@@ -18,6 +18,10 @@ impl SyntaxFactory {
         make::ty(text).clone_for_update()
     }
 
+    pub fn whitespace(&self, text: &str) -> SyntaxToken {
+        make::tokens::whitespace(text)
+    }
+
     pub fn type_param(
         &self,
         name: ast::Name,

crates/syntax/src/syntax_editor.rs

@@ -16,7 +16,7 @@ use rustc_hash::FxHashMap;
 use crate::{SyntaxElement, SyntaxNode, SyntaxToken};
 
 mod edit_algo;
-mod edits;
+pub mod edits;
 mod mapping;
 
 pub use mapping::{SyntaxMapping, SyntaxMappingBuilder};

crates/syntax/src/syntax_editor/edits.rs

@@ -1,8 +1,13 @@
 //! Structural editing for ast using `SyntaxEditor`
 
 use crate::{
-    ast::make, ast::AstNode, ast::Fn, ast::GenericParam, ast::HasGenericParams, ast::HasName,
-    syntax_editor::Position, syntax_editor::SyntaxEditor, SyntaxKind,
+    algo::neighbor,
+    ast::{
+        self, make, syntax_factory::SyntaxFactory, AstNode, Fn, GenericParam, HasGenericParams,
+        HasName,
+    },
+    syntax_editor::{Position, SyntaxEditor},
+    AstToken, Direction, SyntaxKind,
 };
 
 impl SyntaxEditor {
@@ -70,3 +75,65 @@ impl SyntaxEditor {
         }
     }
 }
+
+pub trait Removable: AstNode {
+    fn remove(&self, editor: &mut SyntaxEditor);
+}
+
+impl Removable for ast::Use {
+    fn remove(&self, editor: &mut SyntaxEditor) {
+        let make = SyntaxFactory::new();
+
+        let next_ws = self
+            .syntax()
+            .next_sibling_or_token()
+            .and_then(|it| it.into_token())
+            .and_then(ast::Whitespace::cast);
+        if let Some(next_ws) = next_ws {
+            let ws_text = next_ws.syntax().text();
+            if let Some(rest) = ws_text.strip_prefix('\n') {
+                if rest.is_empty() {
+                    editor.delete(next_ws.syntax());
+                } else {
+                    editor.replace(next_ws.syntax(), make.whitespace(rest));
+                }
+            }
+        }
+        let prev_ws = self
+            .syntax()
+            .prev_sibling_or_token()
+            .and_then(|it| it.into_token())
+            .and_then(ast::Whitespace::cast);
+        if let Some(prev_ws) = prev_ws {
+            let ws_text = prev_ws.syntax().text();
+            let prev_newline = ws_text.rfind('\n').map(|x| x + 1).unwrap_or(0);
+            let rest = &ws_text[0..prev_newline];
+            if rest.is_empty() {
+                editor.delete(prev_ws.syntax());
+            } else {
+                editor.replace(prev_ws.syntax(), make.whitespace(rest));
+            }
+        }
+
+        editor.delete(self.syntax());
+    }
+}
+
+impl Removable for ast::UseTree {
+    fn remove(&self, editor: &mut SyntaxEditor) {
+        for dir in [Direction::Next, Direction::Prev] {
+            if let Some(next_use_tree) = neighbor(self, dir) {
+                let separators = self
+                    .syntax()
+                    .siblings_with_tokens(dir)
+                    .skip(1)
+                    .take_while(|it| it.as_node() != Some(next_use_tree.syntax()));
+                for sep in separators {
+                    editor.delete(sep);
+                }
+                break;
+            }
+        }
+        editor.delete(self.syntax());
+    }
+}