13 files changed, 487 insertions, 215 deletions

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index e7745c6cd..58c8f083a 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -126,8 +126,8 @@ jobs:
     - run: npm ci
       working-directory: ./editors/code
 
-    # - run: npm audit || { sleep 10 && npm audit; } || { sleep 30 && npm audit; }
-    #   working-directory: ./editors/code
+    - run: npm audit || { sleep 10 && npm audit; } || { sleep 30 && npm audit; }
+      working-directory: ./editors/code
 
     - run: npm run lint
       working-directory: ./editors/code
diff --git a/Cargo.lock b/Cargo.lock
index f76857724..3f4d9204c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -594,9 +594,9 @@ checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 
 [[package]]
 name = "libc"
-version = "0.2.67"
+version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb147597cdf94ed43ab7a9038716637d2d1bf2bc571da995d0028dec06bd3018"
+checksum = "dea0c0405123bba743ee3f91f49b1c7cfb684eef0da0a50110f758ccf24cdff0"
 
 [[package]]
 name = "linked-hash-map"
@@ -845,9 +845,9 @@ checksum = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
 
 [[package]]
 name = "proc-macro-hack"
-version = "0.5.11"
+version = "0.5.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ecd45702f76d6d3c75a80564378ae228a85f0b59d2f3ed43c91b4a69eb2ebfc5"
+checksum = "f918f2b601f93baa836c1c2945faef682ba5b6d4828ecb45eeb7cc3c71b811b4"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1399,18 +1399,18 @@ checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 
 [[package]]
 name = "serde"
-version = "1.0.104"
+version = "1.0.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "414115f25f818d7dfccec8ee535d76949ae78584fc4f79a6f45a904bf8ab4449"
+checksum = "e707fbbf255b8fc8c3b99abb91e7257a622caeb20a9818cbadbeeede4e0932ff"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.104"
+version = "1.0.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "128f9e303a5a29922045a830221b8f78ec74a5f544944f3d5984f8ec3895ef64"
+checksum = "ac5d00fc561ba2724df6758a17de23df5914f20e41cb00f94d5b7ae42fffaff8"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1529,9 +1529,9 @@ checksum = "20431e104bfecc1a40872578dbc390e10290a0e9c35fffe3ce6f73c15a9dbfc2"
 
 [[package]]
 name = "thin-dst"
-version = "1.0.0"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c52fd98a9e4913c466d83381a59245691875d2f3e04611fca57f964bd8aa96e1"
+checksum = "db3c46be180f1af9673ebb27bc1235396f61ef6965b3fe0dbb2e624deb604f0e"
 
 [[package]]
 name = "thread_local"
diff --git a/crates/ra_assists/src/doc_tests/generated.rs b/crates/ra_assists/src/doc_tests/generated.rs
index 3f56dd508..aef6793e8 100644
--- a/crates/ra_assists/src/doc_tests/generated.rs
+++ b/crates/ra_assists/src/doc_tests/generated.rs
@@ -418,6 +418,20 @@ fn main() {
 }
 
 #[test]
+fn doctest_merge_imports() {
+    check(
+        "merge_imports",
+        r#####"
+use std::<|>fmt::Formatter;
+use std::io;
+"#####,
+        r#####"
+use std::{fmt::Formatter, io};
+"#####,
+    )
+}
+
+#[test]
 fn doctest_merge_match_arms() {
     check(
         "merge_match_arms",
diff --git a/crates/ra_assists/src/handlers/merge_imports.rs b/crates/ra_assists/src/handlers/merge_imports.rs
new file mode 100644
index 000000000..96b1ab86a
--- /dev/null
+++ b/crates/ra_assists/src/handlers/merge_imports.rs
@@ -0,0 +1,154 @@
+use std::iter::successors;
+
+use ast::{edit::AstNodeEdit, make};
+use ra_syntax::{ast, AstNode, AstToken, Direction, InsertPosition, SyntaxElement, T};
+
+use crate::{Assist, AssistCtx, AssistId};
+
+// Assist: merge_imports
+//
+// Merges two imports with a common prefix.
+//
+// ```
+// use std::<|>fmt::Formatter;
+// use std::io;
+// ```
+// ->
+// ```
+// use std::{fmt::Formatter, io};
+// ```
+pub(crate) fn merge_imports(ctx: AssistCtx) -> Option<Assist> {
+    let tree: ast::UseTree = ctx.find_node_at_offset()?;
+    let use_item = tree.syntax().parent().and_then(ast::UseItem::cast)?;
+    let (merged, to_delete) = [Direction::Prev, Direction::Next]
+        .iter()
+        .copied()
+        .filter_map(|dir| next_use_item(&use_item, dir))
+        .filter_map(|it| Some((it.clone(), it.use_tree()?)))
+        .find_map(|(use_item, use_tree)| {
+            Some((try_merge_trees(&tree, &use_tree)?, use_item.clone()))
+        })?;
+    let mut offset = ctx.frange.range.start();
+    ctx.add_assist(AssistId("merge_imports"), "Merge imports", |edit| {
+        edit.replace_ast(tree, merged);
+
+        let mut range = to_delete.syntax().text_range();
+        let next_ws = to_delete
+            .syntax()
+            .next_sibling_or_token()
+            .and_then(|it| it.into_token())
+            .and_then(ast::Whitespace::cast);
+        if let Some(ws) = next_ws {
+            range = range.extend_to(&ws.syntax().text_range())
+        }
+        edit.delete(range);
+        if range.end() <= offset {
+            offset -= range.len();
+        }
+        edit.set_cursor(offset);
+    })
+}
+
+fn next_use_item(this_use_item: &ast::UseItem, direction: Direction) -> Option<ast::UseItem> {
+    this_use_item.syntax().siblings(direction).skip(1).find_map(ast::UseItem::cast)
+}
+
+fn try_merge_trees(old: &ast::UseTree, new: &ast::UseTree) -> Option<ast::UseTree> {
+    let lhs_path = old.path()?;
+    let rhs_path = new.path()?;
+
+    let (lhs_prefix, rhs_prefix) = common_prefix(&lhs_path, &rhs_path)?;
+
+    let lhs = old.split_prefix(&lhs_prefix);
+    let rhs = new.split_prefix(&rhs_prefix);
+
+    let mut to_insert: Vec<SyntaxElement> = Vec::new();
+    to_insert.push(make::token(T![,]).into());
+    to_insert.push(make::tokens::single_space().into());
+    to_insert.extend(
+        rhs.use_tree_list()?
+            .syntax()
+            .children_with_tokens()
+            .filter(|it| it.kind() != T!['{'] && it.kind() != T!['}']),
+    );
+    let use_tree_list = lhs.use_tree_list()?;
+    let pos = InsertPosition::Before(use_tree_list.r_curly()?.into());
+    let use_tree_list = use_tree_list.insert_children(pos, to_insert);
+    Some(lhs.with_use_tree_list(use_tree_list))
+}
+
+fn common_prefix(lhs: &ast::Path, rhs: &ast::Path) -> Option<(ast::Path, ast::Path)> {
+    let mut res = None;
+    let mut lhs_curr = first_path(&lhs);
+    let mut rhs_curr = first_path(&rhs);
+    loop {
+        match (lhs_curr.segment(), rhs_curr.segment()) {
+            (Some(lhs), Some(rhs)) if lhs.syntax().text() == rhs.syntax().text() => (),
+            _ => break,
+        }
+        res = Some((lhs_curr.clone(), rhs_curr.clone()));
+
+        match (lhs_curr.parent_path(), rhs_curr.parent_path()) {
+            (Some(lhs), Some(rhs)) => {
+                lhs_curr = lhs;
+                rhs_curr = rhs;
+            }
+            _ => break,
+        }
+    }
+
+    res
+}
+
+fn first_path(path: &ast::Path) -> ast::Path {
+    successors(Some(path.clone()), |it| it.qualifier()).last().unwrap()
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::helpers::check_assist;
+
+    use super::*;
+
+    #[test]
+    fn test_merge_first() {
+        check_assist(
+            merge_imports,
+            r"
+use std::fmt<|>::Debug;
+use std::fmt::Display;
+",
+            r"
+use std::fmt<|>::{Debug, Display};
+",
+        )
+    }
+
+    #[test]
+    fn test_merge_second() {
+        check_assist(
+            merge_imports,
+            r"
+use std::fmt::Debug;
+use std::fmt<|>::Display;
+",
+            r"
+use std::fmt<|>::{Display, Debug};
+",
+        )
+    }
+
+    #[test]
+    #[ignore]
+    fn test_merge_nested() {
+        check_assist(
+            merge_imports,
+            r"
+use std::{fmt<|>::Debug, fmt::Display};
+",
+            r"
+use std::{fmt::{Debug, Display}};
+",
+        )
+    }
+}
diff --git a/crates/ra_assists/src/handlers/move_bounds.rs b/crates/ra_assists/src/handlers/move_bounds.rs
index 0b501f3e5..93f26f51a 100644
--- a/crates/ra_assists/src/handlers/move_bounds.rs
+++ b/crates/ra_assists/src/handlers/move_bounds.rs
@@ -1,6 +1,6 @@
 use ra_syntax::{
-    ast::{self, edit, make, AstNode, NameOwner, TypeBoundsOwner},
-    SyntaxElement,
+    ast::{self, edit::AstNodeEdit, make, AstNode, NameOwner, TypeBoundsOwner},
+    match_ast,
     SyntaxKind::*,
 };
 
@@ -34,15 +34,18 @@ pub(crate) fn move_bounds_to_where_clause(ctx: AssistCtx) -> Option<Assist> {
         return None;
     }
 
-    let anchor: SyntaxElement = match parent.kind() {
-        FN_DEF => ast::FnDef::cast(parent)?.body()?.syntax().clone().into(),
-        TRAIT_DEF => ast::TraitDef::cast(parent)?.item_list()?.syntax().clone().into(),
-        IMPL_DEF => ast::ImplDef::cast(parent)?.item_list()?.syntax().clone().into(),
-        ENUM_DEF => ast::EnumDef::cast(parent)?.variant_list()?.syntax().clone().into(),
-        STRUCT_DEF => parent
-            .children_with_tokens()
-            .find(|it| it.kind() == RECORD_FIELD_DEF_LIST || it.kind() == SEMI)?,
-        _ => return None,
+    let anchor = match_ast! {
+        match parent {
+            ast::FnDef(it) => it.body()?.syntax().clone().into(),
+            ast::TraitDef(it) => it.item_list()?.syntax().clone().into(),
+            ast::ImplDef(it) => it.item_list()?.syntax().clone().into(),
+            ast::EnumDef(it) => it.variant_list()?.syntax().clone().into(),
+            ast::StructDef(it) => {
+                it.syntax().children_with_tokens()
+                    .find(|it| it.kind() == RECORD_FIELD_DEF_LIST || it.kind() == SEMI)?
+            },
+            _ => return None
+        }
     };
 
     ctx.add_assist(AssistId("move_bounds_to_where_clause"), "Move to where clause", |edit| {
@@ -54,7 +57,7 @@ pub(crate) fn move_bounds_to_where_clause(ctx: AssistCtx) -> Option<Assist> {
                 (type_param, without_bounds)
             });
 
-        let new_type_param_list = edit::replace_descendants(&type_param_list, new_params);
+        let new_type_param_list = type_param_list.replace_descendants(new_params);
         edit.replace_ast(type_param_list.clone(), new_type_param_list);
 
         let where_clause = {
diff --git a/crates/ra_assists/src/handlers/split_import.rs b/crates/ra_assists/src/handlers/split_import.rs
index 292c39f59..d9244f22d 100644
--- a/crates/ra_assists/src/handlers/split_import.rs
+++ b/crates/ra_assists/src/handlers/split_import.rs
@@ -1,9 +1,6 @@
-use std::iter::{once, successors};
+use std::iter::successors;
 
-use ra_syntax::{
-    ast::{self, make},
-    AstNode, T,
-};
+use ra_syntax::{ast, AstNode, T};
 
 use crate::{Assist, AssistCtx, AssistId};
 
@@ -25,7 +22,10 @@ pub(crate) fn split_import(ctx: AssistCtx) -> Option<Assist> {
 
     let use_tree = top_path.syntax().ancestors().find_map(ast::UseTree::cast)?;
 
-    let new_tree = split_use_tree_prefix(&use_tree, &path)?;
+    let new_tree = use_tree.split_prefix(&path);
+    if new_tree == use_tree {
+        return None;
+    }
     let cursor = ctx.frange.range.start();
 
     ctx.add_assist(AssistId("split_import"), "Split import", |edit| {
@@ -35,23 +35,6 @@ pub(crate) fn split_import(ctx: AssistCtx) -> Option<Assist> {
     })
 }
 
-fn split_use_tree_prefix(use_tree: &ast::UseTree, prefix: &ast::Path) -> Option<ast::UseTree> {
-    let suffix = split_path_prefix(&prefix)?;
-    let use_tree = make::use_tree(suffix.clone(), use_tree.use_tree_list(), use_tree.alias());
-    let nested = make::use_tree_list(once(use_tree));
-    let res = make::use_tree(prefix.clone(), Some(nested), None);
-    Some(res)
-}
-
-fn split_path_prefix(prefix: &ast::Path) -> Option<ast::Path> {
-    let parent = prefix.parent_path()?;
-    let mut res = make::path_unqualified(parent.segment()?);
-    for p in successors(parent.parent_path(), |it| it.parent_path()) {
-        res = make::path_qualified(res, p.segment()?);
-    }
-    Some(res)
-}
-
 #[cfg(test)]
 mod tests {
     use crate::helpers::{check_assist, check_assist_target};
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 62fadcddd..b8704ea7d 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -93,66 +93,68 @@ pub fn resolved_assists(db: &RootDatabase, range: FileRange) -> Vec<ResolvedAssi
 mod handlers {
     use crate::AssistHandler;
 
+    mod add_custom_impl;
     mod add_derive;
     mod add_explicit_type;
     mod add_impl;
-    mod add_custom_impl;
+    mod add_missing_impl_members;
     mod add_new;
     mod apply_demorgan;
     mod auto_import;
-    mod invert_if;
-    mod flip_comma;
-    mod flip_binexpr;
-    mod flip_trait_bound;
     mod change_visibility;
+    mod early_return;
     mod fill_match_arms;
-    mod merge_match_arms;
-    mod introduce_variable;
+    mod flip_binexpr;
+    mod flip_comma;
+    mod flip_trait_bound;
     mod inline_local_variable;
+    mod introduce_variable;
+    mod invert_if;
+    mod merge_imports;
+    mod merge_match_arms;
+    mod move_bounds;
+    mod move_guard;
     mod raw_string;
+    mod remove_dbg;
     mod remove_mut;
     mod replace_if_let_with_match;
+    mod replace_qualified_name_with_use;
     mod split_import;
-    mod remove_dbg;
-    pub(crate) mod replace_qualified_name_with_use;
-    mod add_missing_impl_members;
-    mod move_guard;
-    mod move_bounds;
-    mod early_return;
 
     pub(crate) fn all() -> &'static [AssistHandler] {
         &[
+            add_custom_impl::add_custom_impl,
             add_derive::add_derive,
             add_explicit_type::add_explicit_type,
             add_impl::add_impl,
-            add_custom_impl::add_custom_impl,
+            add_missing_impl_members::add_missing_default_members,
+            add_missing_impl_members::add_missing_impl_members,
             add_new::add_new,
             apply_demorgan::apply_demorgan,
-            invert_if::invert_if,
+            auto_import::auto_import,
             change_visibility::change_visibility,
+            early_return::convert_to_guarded_return,
             fill_match_arms::fill_match_arms,
-            merge_match_arms::merge_match_arms,
-            flip_comma::flip_comma,
             flip_binexpr::flip_binexpr,
+            flip_comma::flip_comma,
             flip_trait_bound::flip_trait_bound,
-            introduce_variable::introduce_variable,
-            replace_if_let_with_match::replace_if_let_with_match,
-            split_import::split_import,
-            remove_dbg::remove_dbg,
-            replace_qualified_name_with_use::replace_qualified_name_with_use,
-            add_missing_impl_members::add_missing_impl_members,
-            add_missing_impl_members::add_missing_default_members,
             inline_local_variable::inline_local_variable,
-            move_guard::move_guard_to_arm_body,
-            move_guard::move_arm_cond_to_match_guard,
+            introduce_variable::introduce_variable,
+            invert_if::invert_if,
+            merge_imports::merge_imports,
+            merge_match_arms::merge_match_arms,
             move_bounds::move_bounds_to_where_clause,
+            move_guard::move_arm_cond_to_match_guard,
+            move_guard::move_guard_to_arm_body,
             raw_string::add_hash,
             raw_string::make_raw_string,
             raw_string::make_usual_string,
             raw_string::remove_hash,
+            remove_dbg::remove_dbg,
             remove_mut::remove_mut,
-            early_return::convert_to_guarded_return,
-            auto_import::auto_import,
+            replace_if_let_with_match::replace_if_let_with_match,
+            replace_qualified_name_with_use::replace_qualified_name_with_use,
+            split_import::split_import,
         ]
     }
 }
diff --git a/crates/ra_syntax/src/ast/edit.rs b/crates/ra_syntax/src/ast/edit.rs
index 40a04b9c5..68dae008f 100644
--- a/crates/ra_syntax/src/ast/edit.rs
+++ b/crates/ra_syntax/src/ast/edit.rs
@@ -23,7 +23,7 @@ impl ast::BinExpr {
     pub fn replace_op(&self, op: SyntaxKind) -> Option<ast::BinExpr> {
         let op_node: SyntaxElement = self.op_details()?.0.into();
         let to_insert: Option<SyntaxElement> = Some(make::token(op).into());
-        Some(replace_children(self, single_node(op_node), to_insert))
+        Some(self.replace_children(single_node(op_node), to_insert))
     }
 }
 
@@ -39,10 +39,10 @@ impl ast::FnDef {
         } else {
             to_insert.push(make::tokens::single_space().into());
             to_insert.push(body.syntax().clone().into());
-            return insert_children(self, InsertPosition::Last, to_insert);
+            return self.insert_children(InsertPosition::Last, to_insert);
         };
         to_insert.push(body.syntax().clone().into());
-        replace_children(self, single_node(old_body_or_semi), to_insert)
+        self.replace_children(single_node(old_body_or_semi), to_insert)
     }
 }
 
@@ -75,7 +75,7 @@ impl ast::ItemList {
         let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
         let to_insert: ArrayVec<[SyntaxElement; 2]> =
             [ws.ws().into(), item.syntax().clone().into()].into();
-        insert_children(self, position, to_insert)
+        self.insert_children(position, to_insert)
     }
 
     fn l_curly(&self) -> Option<SyntaxElement> {
@@ -106,8 +106,8 @@ impl ast::ItemList {
         let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
         let to_insert = iter::once(ws.ws().into());
         match existing_ws {
-            None => insert_children(self, InsertPosition::After(l_curly), to_insert),
-            Some(ws) => replace_children(self, single_node(ws), to_insert),
+            None => self.insert_children(InsertPosition::After(l_curly), to_insert),
+            Some(ws) => self.replace_children(single_node(ws), to_insert),
         }
     }
 }
@@ -184,7 +184,7 @@ impl ast::RecordFieldList {
             InsertPosition::After(anchor) => after_field!(anchor),
         };
 
-        insert_children(self, position, to_insert)
+        self.insert_children(position, to_insert)
     }
 
     fn l_curly(&self) -> Option<SyntaxElement> {
@@ -203,7 +203,7 @@ impl ast::TypeParam {
             Some(it) => it.syntax().clone().into(),
             None => colon.clone().into(),
         };
-        replace_children(self, colon.into()..=end, iter::empty())
+        self.replace_children(colon.into()..=end, iter::empty())
     }
 }
 
@@ -211,8 +211,7 @@ impl ast::Path {
     #[must_use]
     pub fn with_segment(&self, segment: ast::PathSegment) -> ast::Path {
         if let Some(old) = self.segment() {
-            return replace_children(
-                self,
+            return self.replace_children(
                 single_node(old.syntax().clone()),
                 iter::once(segment.syntax().clone().into()),
             );
@@ -234,8 +233,7 @@ impl ast::PathSegment {
 
     fn _with_type_args(&self, type_args: ast::TypeArgList, turbo: bool) -> ast::PathSegment {
         if let Some(old) = self.type_arg_list() {
-            return replace_children(
-                self,
+            return self.replace_children(
                 single_node(old.syntax().clone()),
                 iter::once(type_args.syntax().clone().into()),
             );
@@ -245,7 +243,7 @@ impl ast::PathSegment {
             to_insert.push(make::token(T![::]).into());
         }
         to_insert.push(type_args.syntax().clone().into());
-        insert_children(self, InsertPosition::Last, to_insert)
+        self.insert_children(InsertPosition::Last, to_insert)
     }
 }
 
@@ -253,7 +251,7 @@ impl ast::UseItem {
     #[must_use]
     pub fn with_use_tree(&self, use_tree: ast::UseTree) -> ast::UseItem {
         if let Some(old) = self.use_tree() {
-            return replace_descendants(self, iter::once((old, use_tree)));
+            return self.replace_descendants(iter::once((old, use_tree)));
         }
         self.clone()
     }
@@ -263,7 +261,7 @@ impl ast::UseTree {
     #[must_use]
     pub fn with_path(&self, path: ast::Path) -> ast::UseTree {
         if let Some(old) = self.path() {
-            return replace_descendants(self, iter::once((old, path)));
+            return self.replace_descendants(iter::once((old, path)));
         }
         self.clone()
     }
@@ -271,10 +269,30 @@ impl ast::UseTree {
     #[must_use]
     pub fn with_use_tree_list(&self, use_tree_list: ast::UseTreeList) -> ast::UseTree {
         if let Some(old) = self.use_tree_list() {
-            return replace_descendants(self, iter::once((old, use_tree_list)));
+            return self.replace_descendants(iter::once((old, use_tree_list)));
         }
         self.clone()
     }
+
+    #[must_use]
+    pub fn split_prefix(&self, prefix: &ast::Path) -> ast::UseTree {
+        let suffix = match split_path_prefix(&prefix) {
+            Some(it) => it,
+            None => return self.clone(),
+        };
+        let use_tree = make::use_tree(suffix.clone(), self.use_tree_list(), self.alias());
+        let nested = make::use_tree_list(iter::once(use_tree));
+        return make::use_tree(prefix.clone(), Some(nested), None);
+
+        fn split_path_prefix(prefix: &ast::Path) -> Option<ast::Path> {
+            let parent = prefix.parent_path()?;
+            let mut res = make::path_unqualified(parent.segment()?);
+            for p in iter::successors(parent.parent_path(), |it| it.parent_path()) {
+                res = make::path_qualified(res, p.segment()?);
+            }
+            Some(res)
+        }
+    }
 }
 
 #[must_use]
@@ -295,19 +313,6 @@ fn strip_attrs_and_docs_inner(mut node: SyntaxNode) -> SyntaxNode {
     node
 }
 
-#[must_use]
-pub fn replace_descendants<N: AstNode, D: AstNode>(
-    parent: &N,
-    replacement_map: impl IntoIterator<Item = (D, D)>,
-) -> N {
-    let map = replacement_map
-        .into_iter()
-        .map(|(from, to)| (from.syntax().clone().into(), to.syntax().clone().into()))
-        .collect::<FxHashMap<SyntaxElement, _>>();
-    let new_syntax = algo::replace_descendants(parent.syntax(), |n| map.get(n).cloned());
-    N::cast(new_syntax).unwrap()
-}
-
 #[derive(Debug, Clone, Copy)]
 pub struct IndentLevel(pub u8);
 
@@ -411,31 +416,48 @@ fn prev_tokens(token: SyntaxToken) -> impl Iterator<Item = SyntaxToken> {
     iter::successors(Some(token), |token| token.prev_token())
 }
 
-#[must_use]
-fn insert_children<N: AstNode>(
-    parent: &N,
-    position: InsertPosition<SyntaxElement>,
-    to_insert: impl IntoIterator<Item = SyntaxElement>,
-) -> N {
-    let new_syntax = algo::insert_children(parent.syntax(), position, to_insert);
-    N::cast(new_syntax).unwrap()
+pub trait AstNodeEdit: AstNode + Sized {
+    #[must_use]
+    fn insert_children(
+        &self,
+        position: InsertPosition<SyntaxElement>,
+        to_insert: impl IntoIterator<Item = SyntaxElement>,
+    ) -> Self {
+        let new_syntax = algo::insert_children(self.syntax(), position, to_insert);
+        Self::cast(new_syntax).unwrap()
+    }
+
+    #[must_use]
+    fn replace_children(
+        &self,
+        to_replace: RangeInclusive<SyntaxElement>,
+        to_insert: impl IntoIterator<Item = SyntaxElement>,
+    ) -> Self {
+        let new_syntax = algo::replace_children(self.syntax(), to_replace, to_insert);
+        Self::cast(new_syntax).unwrap()
+    }
+
+    #[must_use]
+    fn replace_descendants<D: AstNode>(
+        &self,
+        replacement_map: impl IntoIterator<Item = (D, D)>,
+    ) -> Self {
+        let map = replacement_map
+            .into_iter()
+            .map(|(from, to)| (from.syntax().clone().into(), to.syntax().clone().into()))
+            .collect::<FxHashMap<SyntaxElement, _>>();
+        let new_syntax = algo::replace_descendants(self.syntax(), |n| map.get(n).cloned());
+        Self::cast(new_syntax).unwrap()
+    }
 }
 
+impl<N: AstNode> AstNodeEdit for N {}
+
 fn single_node(element: impl Into<SyntaxElement>) -> RangeInclusive<SyntaxElement> {
     let element = element.into();
     element.clone()..=element
 }
 
-#[must_use]
-fn replace_children<N: AstNode>(
-    parent: &N,
-    to_replace: RangeInclusive<SyntaxElement>,
-    to_insert: impl IntoIterator<Item = SyntaxElement>,
-) -> N {
-    let new_syntax = algo::replace_children(parent.syntax(), to_replace, to_insert);
-    N::cast(new_syntax).unwrap()
-}
-
 #[test]
 fn test_increase_indent() {
     let arm_list = {
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index d5986e8b4..c3ae8f90e 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -167,6 +167,20 @@ impl ast::UseTreeList {
             .and_then(ast::UseTree::cast)
             .expect("UseTreeLists are always nested in UseTrees")
     }
+    pub fn l_curly(&self) -> Option<SyntaxToken> {
+        self.token(T!['{'])
+    }
+
+    pub fn r_curly(&self) -> Option<SyntaxToken> {
+        self.token(T!['}'])
+    }
+
+    fn token(&self, kind: SyntaxKind) -> Option<SyntaxToken> {
+        self.syntax()
+            .children_with_tokens()
+            .filter_map(|it| it.into_token())
+            .find(|it| it.kind() == kind)
+    }
 }
 
 impl ast::ImplDef {
diff --git a/crates/ra_syntax/src/lib.rs b/crates/ra_syntax/src/lib.rs
index e3f74da6d..cef926ed3 100644
--- a/crates/ra_syntax/src/lib.rs
+++ b/crates/ra_syntax/src/lib.rs
@@ -179,10 +179,10 @@ macro_rules! match_ast {
     (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
 
     (match ($node:expr) {
-        $( ast::$ast:ident($it:ident) => $res:block, )*
+        $( ast::$ast:ident($it:ident) => $res:expr, )*
         _ => $catch_all:expr $(,)?
     }) => {{
-        $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
+        $( if let Some($it) = ast::$ast::cast($node.clone()) { $res } else )*
         { $catch_all }
     }};
 }
diff --git a/docs/user/assists.md b/docs/user/assists.md
index 9861332af..e2850b4dd 100644
--- a/docs/user/assists.md
+++ b/docs/user/assists.md
@@ -402,6 +402,19 @@ fn main() {
 }
 ```
 
+## `merge_imports`
+
+Merges two imports with a common prefix.
+
+```rust
+// BEFORE
+use std::┃fmt::Formatter;
+use std::io;
+
+// AFTER
+use std::{fmt::Formatter, io};
+```
+
 ## `merge_match_arms`
 
 Merges identical match arms.
diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index c1fe620ef..787f1b17a 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -48,17 +48,6 @@
                 "builtin-modules": "^3.1.0",
                 "is-module": "^1.0.0",
                 "resolve": "^1.14.2"
-            },
-            "dependencies": {
-                "resolve": {
-                    "version": "1.15.0",
-                    "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.15.0.tgz",
-                    "integrity": "sha512-+hTmAldEGE80U2wJJDC1lebb5jWqvTYAfm3YZ1ckk1gBr0MnCqUKlwK1e+anaFljIl+F5tR5IoZcm4ZDA1zMQw==",
-                    "dev": true,
-                    "requires": {
-                        "path-parse": "^1.0.6"
-                    }
-                }
             }
         },
         "@rollup/pluginutils": {
@@ -70,6 +59,12 @@
                 "estree-walker": "^1.0.1"
             }
         },
+        "@types/color-name": {
+            "version": "1.1.1",
+            "resolved": "https://registry.npmjs.org/@types/color-name/-/color-name-1.1.1.tgz",
+            "integrity": "sha512-rr+OQyAjxze7GgWrSaJwydHStIhHq2lvY3BOC2Mj7KnzI7XK0Uw1TOOdI9lDoajEbSWLiYgoo4f1R51erQfhPQ==",
+            "dev": true
+        },
         "@types/eslint-visitor-keys": {
             "version": "1.0.0",
             "resolved": "https://registry.npmjs.org/@types/eslint-visitor-keys/-/eslint-visitor-keys-1.0.0.tgz",
@@ -120,12 +115,12 @@
             "dev": true
         },
         "@typescript-eslint/eslint-plugin": {
-            "version": "2.23.0",
-            "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-2.23.0.tgz",
-            "integrity": "sha512-8iA4FvRsz8qTjR0L/nK9RcRUN3QtIHQiOm69FzV7WS3SE+7P7DyGGwh3k4UNR2JBbk+Ej2Io+jLAaqKibNhmtw==",
+            "version": "2.24.0",
+            "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-2.24.0.tgz",
+            "integrity": "sha512-wJRBeaMeT7RLQ27UQkDFOu25MqFOBus8PtOa9KaT5ZuxC1kAsd7JEHqWt4YXuY9eancX0GK9C68i5OROnlIzBA==",
             "dev": true,
             "requires": {
-                "@typescript-eslint/experimental-utils": "2.23.0",
+                "@typescript-eslint/experimental-utils": "2.24.0",
                 "eslint-utils": "^1.4.3",
                 "functional-red-black-tree": "^1.0.1",
                 "regexpp": "^3.0.0",
@@ -133,32 +128,32 @@
             }
         },
         "@typescript-eslint/experimental-utils": {
-            "version": "2.23.0",
-            "resolved": "https://registry.npmjs.org/@typescript-eslint/experimental-utils/-/experimental-utils-2.23.0.tgz",
-            "integrity": "sha512-OswxY59RcXH3NNPmq+4Kis2CYZPurRU6mG5xPcn24CjFyfdVli5mySwZz/g/xDbJXgDsYqNGq7enV0IziWGXVQ==",
+            "version": "2.24.0",
+            "resolved": "https://registry.npmjs.org/@typescript-eslint/experimental-utils/-/experimental-utils-2.24.0.tgz",
+            "integrity": "sha512-DXrwuXTdVh3ycNCMYmWhUzn/gfqu9N0VzNnahjiDJvcyhfBy4gb59ncVZVxdp5XzBC77dCncu0daQgOkbvPwBw==",
             "dev": true,
             "requires": {
                 "@types/json-schema": "^7.0.3",
-                "@typescript-eslint/typescript-estree": "2.23.0",
+                "@typescript-eslint/typescript-estree": "2.24.0",
                 "eslint-scope": "^5.0.0"
             }
         },
         "@typescript-eslint/parser": {
-            "version": "2.23.0",
-            "resolved": "https://registry.npmjs.org/@typescript-eslint/parser/-/parser-2.23.0.tgz",
-            "integrity": "sha512-k61pn/Nepk43qa1oLMiyqApC6x5eP5ddPz6VUYXCAuXxbmRLqkPYzkFRKl42ltxzB2luvejlVncrEpflgQoSUg==",
+            "version": "2.24.0",
+            "resolved": "https://registry.npmjs.org/@typescript-eslint/parser/-/parser-2.24.0.tgz",
+            "integrity": "sha512-H2Y7uacwSSg8IbVxdYExSI3T7uM1DzmOn2COGtCahCC3g8YtM1xYAPi2MAHyfPs61VKxP/J/UiSctcRgw4G8aw==",
             "dev": true,
             "requires": {
                 "@types/eslint-visitor-keys": "^1.0.0",
-                "@typescript-eslint/experimental-utils": "2.23.0",
-                "@typescript-eslint/typescript-estree": "2.23.0",
+                "@typescript-eslint/experimental-utils": "2.24.0",
+                "@typescript-eslint/typescript-estree": "2.24.0",
                 "eslint-visitor-keys": "^1.1.0"
             }
         },
         "@typescript-eslint/typescript-estree": {
-            "version": "2.23.0",
-            "resolved": "https://registry.npmjs.org/@typescript-eslint/typescript-estree/-/typescript-estree-2.23.0.tgz",
-            "integrity": "sha512-pmf7IlmvXdlEXvE/JWNNJpEvwBV59wtJqA8MLAxMKLXNKVRC3HZBXR/SlZLPWTCcwOSg9IM7GeRSV3SIerGVqw==",
+            "version": "2.24.0",
+            "resolved": "https://registry.npmjs.org/@typescript-eslint/typescript-estree/-/typescript-estree-2.24.0.tgz",
+            "integrity": "sha512-RJ0yMe5owMSix55qX7Mi9V6z2FDuuDpN6eR5fzRJrp+8in9UF41IGNQHbg5aMK4/PjVaEQksLvz0IA8n+Mr/FA==",
             "dev": true,
             "requires": {
                 "debug": "^4.1.1",
@@ -177,15 +172,15 @@
             "dev": true
         },
         "acorn-jsx": {
-            "version": "5.1.0",
-            "resolved": "https://registry.npmjs.org/acorn-jsx/-/acorn-jsx-5.1.0.tgz",
-            "integrity": "sha512-tMUqwBWfLFbJbizRmEcWSLw6HnFzfdJs2sOJEOwwtVPMoH/0Ay+E703oZz78VSXZiiDcZrQ5XKjPIUQixhmgVw==",
+            "version": "5.2.0",
+            "resolved": "https://registry.npmjs.org/acorn-jsx/-/acorn-jsx-5.2.0.tgz",
+            "integrity": "sha512-HiUX/+K2YpkpJ+SzBffkM/AQ2YE03S0U1kjTLVpoJdhZMOWy8qvXVN9JdLqv2QsaQ6MPYQIuNmwD8zOiYUofLQ==",
             "dev": true
         },
         "ajv": {
-            "version": "6.11.0",
-            "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.11.0.tgz",
-            "integrity": "sha512-nCprB/0syFYy9fVYU1ox1l2KN8S9I+tziH8D4zdZuLT3N6RMlGSGt5FSTpAiHB/Whv8Qs1cWHma1aMKZyaHRKA==",
+            "version": "6.12.0",
+            "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.0.tgz",
+            "integrity": "sha512-D6gFiFA0RRLyUbvijN74DWAjXSFxWKaWP7mldxkVhyhAV3+SWA9HEJPHQ2c9soIeTFJqcSdFDGFgdqs1iUU2Hw==",
             "dev": true,
             "requires": {
                 "fast-deep-equal": "^3.1.1",
@@ -195,12 +190,20 @@
             }
         },
         "ansi-escapes": {
-            "version": "4.3.0",
-            "resolved": "https://registry.npmjs.org/ansi-escapes/-/ansi-escapes-4.3.0.tgz",
-            "integrity": "sha512-EiYhwo0v255HUL6eDyuLrXEkTi7WwVCLAw+SeOQ7M7qdun1z1pum4DEm/nuqIVbPvi9RPPc9k9LbyBv6H0DwVg==",
+            "version": "4.3.1",
+            "resolved": "https://registry.npmjs.org/ansi-escapes/-/ansi-escapes-4.3.1.tgz",
+            "integrity": "sha512-JWF7ocqNrp8u9oqpgV+wH5ftbt+cfvv+PTjOvKLT3AdYly/LmORARfEVT1iyjwN+4MqE5UmVKoAdIBqeoCHgLA==",
             "dev": true,
             "requires": {
-                "type-fest": "^0.8.1"
+                "type-fest": "^0.11.0"
+            },
+            "dependencies": {
+                "type-fest": {
+                    "version": "0.11.0",
+                    "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-0.11.0.tgz",
+                    "integrity": "sha512-OdjXJxnCN1AvyLSzeKIgXTXxV+99ZuXl3Hpo9XpJAv9MBcHrrJOQ5kV7ypXOuQie+AmWG25hLbiKdwYTifzcfQ==",
+                    "dev": true
+                }
             }
         },
         "ansi-regex": {
@@ -612,13 +615,13 @@
             "dev": true
         },
         "espree": {
-            "version": "6.1.2",
-            "resolved": "https://registry.npmjs.org/espree/-/espree-6.1.2.tgz",
-            "integrity": "sha512-2iUPuuPP+yW1PZaMSDM9eyVf8D5P0Hi8h83YtZ5bPc/zHYjII5khoixIUTMO794NOY8F/ThF1Bo8ncZILarUTA==",
+            "version": "6.2.1",
+            "resolved": "https://registry.npmjs.org/espree/-/espree-6.2.1.tgz",
+            "integrity": "sha512-ysCxRQY3WaXJz9tdbWOwuWr5Y/XrPTGX9Kiz3yoUXwW0VZ4w30HTkQLaGx/+ttFjF8i+ACbArnB4ce68a9m5hw==",
             "dev": true,
             "requires": {
-                "acorn": "^7.1.0",
-                "acorn-jsx": "^5.1.0",
+                "acorn": "^7.1.1",
+                "acorn-jsx": "^5.2.0",
                 "eslint-visitor-keys": "^1.1.0"
             }
         },
@@ -673,17 +676,6 @@
                 "chardet": "^0.7.0",
                 "iconv-lite": "^0.4.24",
                 "tmp": "^0.0.33"
-            },
-            "dependencies": {
-                "tmp": {
-                    "version": "0.0.33",
-                    "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.33.tgz",
-                    "integrity": "sha512-jRCJlojKnZ3addtTOjdIqoRuPEKBvNXcGYqzO6zWZX8KfKEpnGY5jfggJQ3EjKuu8D4bJRr0y+cYJFmYbImXGw==",
-                    "dev": true,
-                    "requires": {
-                        "os-tmpdir": "~1.0.2"
-                    }
-                }
             }
         },
         "fast-deep-equal": {
@@ -765,6 +757,13 @@
             "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8=",
             "dev": true
         },
+        "fsevents": {
+            "version": "2.1.2",
+            "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.1.2.tgz",
+            "integrity": "sha512-R4wDiBwZ0KzpgOWetKDug1FZcYhqYnUYKtfZYt4mD5SBz76q0KR4Q9o7GIPamsVPGmW3EYPPJ0dOOjvx32ldZA==",
+            "dev": true,
+            "optional": true
+        },
         "functional-red-black-tree": {
             "version": "1.0.1",
             "resolved": "https://registry.npmjs.org/functional-red-black-tree/-/functional-red-black-tree-1.0.1.tgz",
@@ -795,9 +794,9 @@
             }
         },
         "globals": {
-            "version": "12.3.0",
-            "resolved": "https://registry.npmjs.org/globals/-/globals-12.3.0.tgz",
-            "integrity": "sha512-wAfjdLgFsPZsklLJvOBUBmzYE8/CwhEqSBEMRXA3qxIiNtyqvjYurAtIfDh6chlEPUfmTY3MnZh5Hfh4q0UlIw==",
+            "version": "12.4.0",
+            "resolved": "https://registry.npmjs.org/globals/-/globals-12.4.0.tgz",
+            "integrity": "sha512-BWICuzzDvDoH54NHKCseDanAhE3CeDorgDL5MT6LMXXj2WCnd9UC2szdk4AWLfjdgNBCXLUanXYcpBBKOSWGwg==",
             "dev": true,
             "requires": {
                 "type-fest": "^0.8.1"
@@ -871,24 +870,85 @@
             "dev": true
         },
         "inquirer": {
-            "version": "7.0.4",
-            "resolved": "https://registry.npmjs.org/inquirer/-/inquirer-7.0.4.tgz",
-            "integrity": "sha512-Bu5Td5+j11sCkqfqmUTiwv+tWisMtP0L7Q8WrqA2C/BbBhy1YTdFrvjjlrKq8oagA/tLQBski2Gcx/Sqyi2qSQ==",
+            "version": "7.1.0",
+            "resolved": "https://registry.npmjs.org/inquirer/-/inquirer-7.1.0.tgz",
+            "integrity": "sha512-5fJMWEmikSYu0nv/flMc475MhGbB7TSPd/2IpFV4I4rMklboCH2rQjYY5kKiYGHqUF9gvaambupcJFFG9dvReg==",
             "dev": true,
             "requires": {
                 "ansi-escapes": "^4.2.1",
-                "chalk": "^2.4.2",
+                "chalk": "^3.0.0",
                 "cli-cursor": "^3.1.0",
                 "cli-width": "^2.0.0",
                 "external-editor": "^3.0.3",
                 "figures": "^3.0.0",
                 "lodash": "^4.17.15",
                 "mute-stream": "0.0.8",
-                "run-async": "^2.2.0",
+                "run-async": "^2.4.0",
                 "rxjs": "^6.5.3",
                 "string-width": "^4.1.0",
-                "strip-ansi": "^5.1.0",
+                "strip-ansi": "^6.0.0",
                 "through": "^2.3.6"
+            },
+            "dependencies": {
+                "ansi-styles": {
+                    "version": "4.2.1",
+                    "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-4.2.1.tgz",
+                    "integrity": "sha512-9VGjrMsG1vePxcSweQsN20KY/c4zN0h9fLjqAbwbPfahM3t+NL+M9HC8xeXG2I8pX5NoamTGNuomEUFI7fcUjA==",
+                    "dev": true,
+                    "requires": {
+                        "@types/color-name": "^1.1.1",
+                        "color-convert": "^2.0.1"
+                    }
+                },
+                "chalk": {
+                    "version": "3.0.0",
+                    "resolved": "https://registry.npmjs.org/chalk/-/chalk-3.0.0.tgz",
+                    "integrity": "sha512-4D3B6Wf41KOYRFdszmDqMCGq5VV/uMAB273JILmO+3jAlh8X4qDtdtgCR3fxtbLEMzSx22QdhnDcJvu2u1fVwg==",
+                    "dev": true,
+                    "requires": {
+                        "ansi-styles": "^4.1.0",
+                        "supports-color": "^7.1.0"
+                    }
+                },
+                "color-convert": {
+                    "version": "2.0.1",
+                    "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-2.0.1.tgz",
+                    "integrity": "sha512-RRECPsj7iu/xb5oKYcsFHSppFNnsj/52OVTRKb4zP5onXwVF3zVmmToNcOfGC+CRDpfK/U584fMg38ZHCaElKQ==",
+                    "dev": true,
+                    "requires": {
+                        "color-name": "~1.1.4"
+                    }
+                },
+                "color-name": {
+                    "version": "1.1.4",
+                    "resolved": "https://registry.npmjs.org/color-name/-/color-name-1.1.4.tgz",
+                    "integrity": "sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==",
+                    "dev": true
+                },
+                "has-flag": {
+                    "version": "4.0.0",
+                    "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-4.0.0.tgz",
+                    "integrity": "sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==",
+                    "dev": true
+                },
+                "strip-ansi": {
+                    "version": "6.0.0",
+                    "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-6.0.0.tgz",
+                    "integrity": "sha512-AuvKTrTfQNYNIctbR1K/YGTR1756GycPsg7b9bdV9Duqur4gv6aKqHXah67Z8ImS7WEz5QVcOtlfW2rZEugt6w==",
+                    "dev": true,
+                    "requires": {
+                        "ansi-regex": "^5.0.0"
+                    }
+                },
+                "supports-color": {
+                    "version": "7.1.0",
+                    "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.1.0.tgz",
+                    "integrity": "sha512-oRSIpR8pxT1Wr2FquTNnGet79b3BWljqOuoW/h4oBhxJ/HUbX5nX6JSruTkvXDCFMwDPvsaTTbvMLKZWSy0R5g==",
+                    "dev": true,
+                    "requires": {
+                        "has-flag": "^4.0.0"
+                    }
+                }
             }
         },
         "is-extglob": {
@@ -1008,9 +1068,9 @@
             }
         },
         "magic-string": {
-            "version": "0.25.6",
-            "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.25.6.tgz",
-            "integrity": "sha512-3a5LOMSGoCTH5rbqobC2HuDNRtE2glHZ8J7pK+QZYppyWA36yuNpsX994rIY2nCuyP7CZYy7lQq/X2jygiZ89g==",
+            "version": "0.25.7",
+            "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.25.7.tgz",
+            "integrity": "sha512-4CrMT5DOHTDk4HYDlzmwu4FVCcIYI8gauveasrdCu2IKIFOJ3f0v/8MDGJCDL9oD2ppz/Av1b0Nj345H9M+XIA==",
             "dev": true,
             "requires": {
                 "sourcemap-codec": "^1.4.4"
@@ -1072,18 +1132,18 @@
             }
         },
         "minimist": {
-            "version": "0.0.8",
-            "resolved": "https://registry.npmjs.org/minimist/-/minimist-0.0.8.tgz",
-            "integrity": "sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0=",
+            "version": "1.2.5",
+            "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.5.tgz",
+            "integrity": "sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw==",
             "dev": true
         },
         "mkdirp": {
-            "version": "0.5.1",
-            "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz",
-            "integrity": "sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=",
+            "version": "0.5.3",
+            "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.3.tgz",
+            "integrity": "sha512-P+2gwrFqx8lhew375MQHHeTlY8AuOJSrGf0R5ddkEndUkmwpgUob/vQuBD1V22/Cw1/lJr4x+EjllSezBThzBg==",
             "dev": true,
             "requires": {
-                "minimist": "0.0.8"
+                "minimist": "^1.2.5"
             }
         },
         "ms": {
@@ -1294,9 +1354,9 @@
             "dev": true
         },
         "resolve": {
-            "version": "1.14.1",
-            "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.14.1.tgz",
-            "integrity": "sha512-fn5Wobh4cxbLzuHaE+nphztHy43/b++4M6SsGFC2gB8uYwf0C8LcarfCz1un7UTW8OFQg9iNjZ4xpcFVGebDPg==",
+            "version": "1.15.1",
+            "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.15.1.tgz",
+            "integrity": "sha512-84oo6ZTtoTUpjgNEr5SJyzQhzL72gaRodsSfyxC/AXRvwu0Yse9H8eF9IpGo7b8YetZhlI6v7ZQ6bKBFV/6S7w==",
             "dev": true,
             "requires": {
                 "path-parse": "^1.0.6"
@@ -1328,20 +1388,18 @@
             }
         },
         "rollup": {
-            "version": "1.32.1",
-            "resolved": "https://registry.npmjs.org/rollup/-/rollup-1.32.1.tgz",
-            "integrity": "sha512-/2HA0Ec70TvQnXdzynFffkjA6XN+1e2pEv/uKS5Ulca40g2L7KuOE3riasHoNVHOsFD5KKZgDsMk1CP3Tw9s+A==",
+            "version": "2.1.0",
+            "resolved": "https://registry.npmjs.org/rollup/-/rollup-2.1.0.tgz",
+            "integrity": "sha512-gfE1455AEazVVTJoeQtcOq/U6GSxwoj4XPSWVsuWmgIxj7sBQNLDOSA82PbdMe+cP8ql8fR1jogPFe8Wg8g4SQ==",
             "dev": true,
             "requires": {
-                "@types/estree": "*",
-                "@types/node": "*",
-                "acorn": "^7.1.0"
+                "fsevents": "~2.1.2"
             }
         },
         "run-async": {
-            "version": "2.3.0",
-            "resolved": "https://registry.npmjs.org/run-async/-/run-async-2.3.0.tgz",
-            "integrity": "sha1-A3GrSuC91yDUFm19/aZP96RFpsA=",
+            "version": "2.4.0",
+            "resolved": "https://registry.npmjs.org/run-async/-/run-async-2.4.0.tgz",
+            "integrity": "sha512-xJTbh/d7Lm7SBhc1tNvTpeCHaEzoyxPrqNlvSdMfBTYwaY++UJFyXUOxAtsRUXjlqOfj8luNaR9vjCh4KeV+pg==",
             "dev": true,
             "requires": {
                 "is-promise": "^2.1.0"
@@ -1544,12 +1602,12 @@
             "dev": true
         },
         "tmp": {
-            "version": "0.0.29",
-            "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.29.tgz",
-            "integrity": "sha1-8lEl/w3Z2jzLDC3Tce4SiLuRKMA=",
+            "version": "0.0.33",
+            "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.33.tgz",
+            "integrity": "sha512-jRCJlojKnZ3addtTOjdIqoRuPEKBvNXcGYqzO6zWZX8KfKEpnGY5jfggJQ3EjKuu8D4bJRr0y+cYJFmYbImXGw==",
             "dev": true,
             "requires": {
-                "os-tmpdir": "~1.0.1"
+                "os-tmpdir": "~1.0.2"
             }
         },
         "tslib": {
@@ -1686,6 +1744,15 @@
                     "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
                     "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==",
                     "dev": true
+                },
+                "tmp": {
+                    "version": "0.0.29",
+                    "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.29.tgz",
+                    "integrity": "sha1-8lEl/w3Z2jzLDC3Tce4SiLuRKMA=",
+                    "dev": true,
+                    "requires": {
+                        "os-tmpdir": "~1.0.1"
+                    }
                 }
             }
         },
diff --git a/editors/code/package.json b/editors/code/package.json
index 6528ff071..150c36845 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -42,10 +42,10 @@
         "@types/node": "^12.12.30",
         "@types/node-fetch": "^2.5.5",
         "@types/vscode": "^1.43.0",
-        "@typescript-eslint/eslint-plugin": "^2.23.0",
-        "@typescript-eslint/parser": "^2.23.0",
+        "@typescript-eslint/eslint-plugin": "^2.24.0",
+        "@typescript-eslint/parser": "^2.24.0",
         "eslint": "^6.8.0",
-        "rollup": "^1.32.1",
+        "rollup": "^2.1.0",
         "tslib": "^1.11.1",
         "typescript": "^3.8.3",
         "typescript-formatter": "^7.2.2",