16 files changed, 240 insertions, 267 deletions

diff --git a/crates/assists/src/assist_context.rs b/crates/assists/src/assist_context.rs
index 91cc63427..321fe77f3 100644
--- a/crates/assists/src/assist_context.rs
+++ b/crates/assists/src/assist_context.rs
@@ -10,7 +10,7 @@ use ide_db::{
 };
 use ide_db::{
     label::Label,
-    source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
+    source_change::{FileSystemEdit, SourceChange},
     RootDatabase,
 };
 use syntax::{
@@ -180,20 +180,12 @@ impl Assists {
 pub(crate) struct AssistBuilder {
     edit: TextEditBuilder,
     file_id: FileId,
-    is_snippet: bool,
-    source_file_edits: Vec<SourceFileEdit>,
-    file_system_edits: Vec<FileSystemEdit>,
+    source_change: SourceChange,
 }
 
 impl AssistBuilder {
     pub(crate) fn new(file_id: FileId) -> AssistBuilder {
-        AssistBuilder {
-            edit: TextEdit::builder(),
-            file_id,
-            is_snippet: false,
-            source_file_edits: Vec::default(),
-            file_system_edits: Vec::default(),
-        }
+        AssistBuilder { edit: TextEdit::builder(), file_id, source_change: SourceChange::default() }
     }
 
     pub(crate) fn edit_file(&mut self, file_id: FileId) {
@@ -204,15 +196,7 @@ impl AssistBuilder {
     fn commit(&mut self) {
         let edit = mem::take(&mut self.edit).finish();
         if !edit.is_empty() {
-            match self.source_file_edits.binary_search_by_key(&self.file_id, |edit| edit.file_id) {
-                Ok(idx) => self.source_file_edits[idx]
-                    .edit
-                    .union(edit)
-                    .expect("overlapping edits for same file"),
-                Err(idx) => self
-                    .source_file_edits
-                    .insert(idx, SourceFileEdit { file_id: self.file_id, edit }),
-            }
+            self.source_change.insert_source_edit(self.file_id, edit);
         }
     }
 
@@ -231,7 +215,7 @@ impl AssistBuilder {
         offset: TextSize,
         snippet: impl Into<String>,
     ) {
-        self.is_snippet = true;
+        self.source_change.is_snippet = true;
         self.insert(offset, snippet);
     }
     /// Replaces specified `range` of text with a given string.
@@ -245,7 +229,7 @@ impl AssistBuilder {
         range: TextRange,
         snippet: impl Into<String>,
     ) {
-        self.is_snippet = true;
+        self.source_change.is_snippet = true;
         self.replace(range, snippet);
     }
     pub(crate) fn replace_ast<N: AstNode>(&mut self, old: N, new: N) {
@@ -260,15 +244,11 @@ impl AssistBuilder {
     pub(crate) fn create_file(&mut self, dst: AnchoredPathBuf, content: impl Into<String>) {
         let file_system_edit =
             FileSystemEdit::CreateFile { dst: dst.clone(), initial_contents: content.into() };
-        self.file_system_edits.push(file_system_edit);
+        self.source_change.push_file_system_edit(file_system_edit);
     }
 
     fn finish(mut self) -> SourceChange {
         self.commit();
-        SourceChange {
-            source_file_edits: mem::take(&mut self.source_file_edits),
-            file_system_edits: mem::take(&mut self.file_system_edits),
-            is_snippet: self.is_snippet,
-        }
+        mem::take(&mut self.source_change)
     }
 }
diff --git a/crates/assists/src/tests.rs b/crates/assists/src/tests.rs
index fef29a0b8..71431b406 100644
--- a/crates/assists/src/tests.rs
+++ b/crates/assists/src/tests.rs
@@ -80,10 +80,8 @@ fn check_doc_test(assist_id: &str, before: &str, after: &str) {
     let actual = {
         let source_change = assist.source_change.unwrap();
         let mut actual = before;
-        for source_file_edit in source_change.source_file_edits {
-            if source_file_edit.file_id == file_id {
-                source_file_edit.edit.apply(&mut actual)
-            }
+        if let Some(source_file_edit) = source_change.get_source_edit(file_id) {
+            source_file_edit.apply(&mut actual);
         }
         actual
     };
@@ -116,37 +114,33 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult, assist_label:
 
     match (assist, expected) {
         (Some(assist), ExpectedResult::After(after)) => {
-            let mut source_change = assist.source_change.unwrap();
+            let source_change = assist.source_change.unwrap();
             assert!(!source_change.source_file_edits.is_empty());
             let skip_header = source_change.source_file_edits.len() == 1
                 && source_change.file_system_edits.len() == 0;
-            source_change.source_file_edits.sort_by_key(|it| it.file_id);
 
             let mut buf = String::new();
-            for source_file_edit in source_change.source_file_edits {
-                let mut text = db.file_text(source_file_edit.file_id).as_ref().to_owned();
-                source_file_edit.edit.apply(&mut text);
+            for (file_id, edit) in source_change.source_file_edits {
+                let mut text = db.file_text(file_id).as_ref().to_owned();
+                edit.apply(&mut text);
                 if !skip_header {
-                    let sr = db.file_source_root(source_file_edit.file_id);
+                    let sr = db.file_source_root(file_id);
                     let sr = db.source_root(sr);
-                    let path = sr.path_for_file(&source_file_edit.file_id).unwrap();
+                    let path = sr.path_for_file(&file_id).unwrap();
                     format_to!(buf, "//- {}\n", path)
                 }
                 buf.push_str(&text);
             }
 
-            for file_system_edit in source_change.file_system_edits.clone() {
-                match file_system_edit {
-                    FileSystemEdit::CreateFile { dst, initial_contents } => {
-                        let sr = db.file_source_root(dst.anchor);
-                        let sr = db.source_root(sr);
-                        let mut base = sr.path_for_file(&dst.anchor).unwrap().clone();
-                        base.pop();
-                        let created_file_path = format!("{}{}", base.to_string(), &dst.path[1..]);
-                        format_to!(buf, "//- {}\n", created_file_path);
-                        buf.push_str(&initial_contents);
-                    }
-                    _ => (),
+            for file_system_edit in source_change.file_system_edits {
+                if let FileSystemEdit::CreateFile { dst, initial_contents } = file_system_edit {
+                    let sr = db.file_source_root(dst.anchor);
+                    let sr = db.source_root(sr);
+                    let mut base = sr.path_for_file(&dst.anchor).unwrap().clone();
+                    base.pop();
+                    let created_file_path = format!("{}{}", base.to_string(), &dst.path[1..]);
+                    format_to!(buf, "//- {}\n", created_file_path);
+                    buf.push_str(&initial_contents);
                 }
             }
 
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 055c0a79c..2e5395b51 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -13,8 +13,7 @@ use hir::{
     diagnostics::{Diagnostic as _, DiagnosticCode, DiagnosticSinkBuilder},
     Semantics,
 };
-use ide_db::base_db::SourceDatabase;
-use ide_db::RootDatabase;
+use ide_db::{base_db::SourceDatabase, RootDatabase};
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
 use syntax::{
@@ -23,7 +22,7 @@ use syntax::{
 };
 use text_edit::TextEdit;
 
-use crate::{FileId, Label, SourceChange, SourceFileEdit};
+use crate::{FileId, Label, SourceChange};
 
 use self::fixes::DiagnosticWithFix;
 
@@ -220,7 +219,7 @@ fn check_unnecessary_braces_in_use_statement(
             Diagnostic::hint(use_range, "Unnecessary braces in use statement".to_string())
                 .with_fix(Some(Fix::new(
                     "Remove unnecessary braces",
-                    SourceFileEdit { file_id, edit }.into(),
+                    SourceChange::from_text_edit(file_id, edit),
                     use_range,
                 ))),
         );
@@ -265,13 +264,11 @@ mod tests {
             .unwrap();
         let fix = diagnostic.fix.unwrap();
         let actual = {
-            let file_id = fix.source_change.source_file_edits.first().unwrap().file_id;
+            let file_id = *fix.source_change.source_file_edits.keys().next().unwrap();
             let mut actual = analysis.file_text(file_id).unwrap().to_string();
 
-            // Go from the last one to the first one, so that ranges won't be affected by previous edits.
-            // FIXME: https://github.com/rust-analyzer/rust-analyzer/issues/4901#issuecomment-644675309
-            for edit in fix.source_change.source_file_edits.iter().rev() {
-                edit.edit.apply(&mut actual);
+            for edit in fix.source_change.source_file_edits.values() {
+                edit.apply(&mut actual);
             }
             actual
         };
@@ -616,7 +613,7 @@ fn test_fn() {
                             Fix {
                                 label: "Create module",
                                 source_change: SourceChange {
-                                    source_file_edits: [],
+                                    source_file_edits: {},
                                     file_system_edits: [
                                         CreateFile {
                                             dst: AnchoredPathBuf {
diff --git a/crates/ide/src/diagnostics/field_shorthand.rs b/crates/ide/src/diagnostics/field_shorthand.rs
index 16c6ea827..5c89e2170 100644
--- a/crates/ide/src/diagnostics/field_shorthand.rs
+++ b/crates/ide/src/diagnostics/field_shorthand.rs
@@ -1,8 +1,7 @@
 //! Suggests shortening `Foo { field: field }` to `Foo { field }` in both
 //! expressions and patterns.
 
-use ide_db::base_db::FileId;
-use ide_db::source_change::SourceFileEdit;
+use ide_db::{base_db::FileId, source_change::SourceChange};
 use syntax::{ast, match_ast, AstNode, SyntaxNode};
 use text_edit::TextEdit;
 
@@ -50,7 +49,7 @@ fn check_expr_field_shorthand(
             Diagnostic::hint(field_range, "Shorthand struct initialization".to_string()).with_fix(
                 Some(Fix::new(
                     "Use struct shorthand initialization",
-                    SourceFileEdit { file_id, edit }.into(),
+                    SourceChange::from_text_edit(file_id, edit),
                     field_range,
                 )),
             ),
@@ -89,7 +88,7 @@ fn check_pat_field_shorthand(
         acc.push(Diagnostic::hint(field_range, "Shorthand struct pattern".to_string()).with_fix(
             Some(Fix::new(
                 "Use struct field shorthand",
-                SourceFileEdit { file_id, edit }.into(),
+                SourceChange::from_text_edit(file_id, edit),
                 field_range,
             )),
         ));
diff --git a/crates/ide/src/diagnostics/fixes.rs b/crates/ide/src/diagnostics/fixes.rs
index d7ad88ed5..e4335119b 100644
--- a/crates/ide/src/diagnostics/fixes.rs
+++ b/crates/ide/src/diagnostics/fixes.rs
@@ -8,9 +8,9 @@ use hir::{
     },
     HasSource, HirDisplay, InFile, Semantics, VariantDef,
 };
-use ide_db::base_db::{AnchoredPathBuf, FileId};
 use ide_db::{
-    source_change::{FileSystemEdit, SourceFileEdit},
+    base_db::{AnchoredPathBuf, FileId},
+    source_change::{FileSystemEdit, SourceChange},
     RootDatabase,
 };
 use syntax::{
@@ -88,7 +88,7 @@ impl DiagnosticWithFix for MissingFields {
         };
         Some(Fix::new(
             "Fill struct fields",
-            SourceFileEdit { file_id: self.file.original_file(sema.db), edit }.into(),
+            SourceChange::from_text_edit(self.file.original_file(sema.db), edit),
             sema.original_range(&field_list_parent.syntax()).range,
         ))
     }
@@ -101,8 +101,7 @@ impl DiagnosticWithFix for MissingOkOrSomeInTailExpr {
         let tail_expr_range = tail_expr.syntax().text_range();
         let replacement = format!("{}({})", self.required, tail_expr.syntax());
         let edit = TextEdit::replace(tail_expr_range, replacement);
-        let source_change =
-            SourceFileEdit { file_id: self.file.original_file(sema.db), edit }.into();
+        let source_change = SourceChange::from_text_edit(self.file.original_file(sema.db), edit);
         let name = if self.required == "Ok" { "Wrap with Ok" } else { "Wrap with Some" };
         Some(Fix::new(name, source_change, tail_expr_range))
     }
@@ -122,8 +121,7 @@ impl DiagnosticWithFix for RemoveThisSemicolon {
             .text_range();
 
         let edit = TextEdit::delete(semicolon);
-        let source_change =
-            SourceFileEdit { file_id: self.file.original_file(sema.db), edit }.into();
+        let source_change = SourceChange::from_text_edit(self.file.original_file(sema.db), edit);
 
         Some(Fix::new("Remove this semicolon", source_change, semicolon))
     }
@@ -204,15 +202,11 @@ fn missing_record_expr_field_fix(
         new_field = format!(",{}", new_field);
     }
 
-    let source_change = SourceFileEdit {
-        file_id: def_file_id,
-        edit: TextEdit::insert(last_field_syntax.text_range().end(), new_field),
-    };
-    return Some(Fix::new(
-        "Create field",
-        source_change.into(),
-        record_expr_field.syntax().text_range(),
-    ));
+    let source_change = SourceChange::from_text_edit(
+        def_file_id,
+        TextEdit::insert(last_field_syntax.text_range().end(), new_field),
+    );
+    return Some(Fix::new("Create field", source_change, record_expr_field.syntax().text_range()));
 
     fn record_field_list(field_def_list: ast::FieldList) -> Option<ast::RecordFieldList> {
         match field_def_list {
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 1e03832ec..afd552008 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -98,7 +98,7 @@ pub use ide_db::{
     label::Label,
     line_index::{LineCol, LineIndex},
     search::SearchScope,
-    source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
+    source_change::{FileSystemEdit, SourceChange},
     symbol_index::Query,
     RootDatabase,
 };
@@ -553,7 +553,7 @@ impl Analysis {
             let rule: ssr::SsrRule = query.parse()?;
             let mut match_finder = ssr::MatchFinder::in_context(db, resolve_context, selections);
             match_finder.add_rule(rule)?;
-            let edits = if parse_only { Vec::new() } else { match_finder.edits() };
+            let edits = if parse_only { Default::default() } else { match_finder.edits() };
             Ok(SourceChange::from(edits))
         })
     }
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index c3ae568c2..039efb26f 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -21,7 +21,7 @@ use text_edit::TextEdit;
 
 use crate::{
     FilePosition, FileSystemEdit, RangeInfo, ReferenceKind, ReferenceSearchResult, SourceChange,
-    SourceFileEdit, TextRange, TextSize,
+    TextRange, TextSize,
 };
 
 type RenameResult<T> = Result<T, RenameError>;
@@ -58,7 +58,7 @@ pub(crate) fn prepare_rename(
         rename_self_to_param(&sema, position, self_token, "dummy")
     } else {
         let RangeInfo { range, .. } = find_all_refs(&sema, position)?;
-        Ok(RangeInfo::new(range, SourceChange::from(vec![])))
+        Ok(RangeInfo::new(range, SourceChange::default()))
     }
     .map(|info| RangeInfo::new(info.range, ()))
 }
@@ -176,7 +176,7 @@ fn source_edit_from_references(
     file_id: FileId,
     references: &[FileReference],
     new_name: &str,
-) -> SourceFileEdit {
+) -> (FileId, TextEdit) {
     let mut edit = TextEdit::builder();
     for reference in references {
         let mut replacement_text = String::new();
@@ -209,8 +209,7 @@ fn source_edit_from_references(
         };
         edit.replace(range, replacement_text);
     }
-
-    SourceFileEdit { file_id, edit: edit.finish() }
+    (file_id, edit.finish())
 }
 
 fn edit_text_range_for_record_field_expr_or_pat(
@@ -250,8 +249,8 @@ fn rename_mod(
     if IdentifierKind::Ident != check_identifier(new_name)? {
         bail!("Invalid name `{0}`: cannot rename module to {0}", new_name);
     }
-    let mut source_file_edits = Vec::new();
-    let mut file_system_edits = Vec::new();
+
+    let mut source_change = SourceChange::default();
 
     let src = module.definition_source(sema.db);
     let file_id = src.file_id.original_file(sema.db);
@@ -265,7 +264,7 @@ fn rename_mod(
             };
             let dst = AnchoredPathBuf { anchor: file_id, path };
             let move_file = FileSystemEdit::MoveFile { src: file_id, dst };
-            file_system_edits.push(move_file);
+            source_change.push_file_system_edit(move_file);
         }
         ModuleSource::Module(..) => {}
     }
@@ -273,20 +272,19 @@ fn rename_mod(
     if let Some(src) = module.declaration_source(sema.db) {
         let file_id = src.file_id.original_file(sema.db);
         let name = src.value.name().unwrap();
-        let edit = SourceFileEdit {
+        source_change.insert_source_edit(
             file_id,
-            edit: TextEdit::replace(name.syntax().text_range(), new_name.into()),
-        };
-        source_file_edits.push(edit);
+            TextEdit::replace(name.syntax().text_range(), new_name.into()),
+        );
     }
 
     let RangeInfo { range, info: refs } = find_all_refs(sema, position)?;
     let ref_edits = refs.references().iter().map(|(&file_id, references)| {
         source_edit_from_references(sema, file_id, references, new_name)
     });
-    source_file_edits.extend(ref_edits);
+    source_change.extend(ref_edits);
 
-    Ok(RangeInfo::new(range, SourceChange::from_edits(source_file_edits, file_system_edits)))
+    Ok(RangeInfo::new(range, source_change))
 }
 
 fn rename_to_self(
@@ -335,20 +333,16 @@ fn rename_to_self(
 
     let RangeInfo { range, info: refs } = find_all_refs(sema, position)?;
 
-    let mut edits = refs
-        .references()
-        .iter()
-        .map(|(&file_id, references)| {
-            source_edit_from_references(sema, file_id, references, "self")
-        })
-        .collect::<Vec<_>>();
-
-    edits.push(SourceFileEdit {
-        file_id: position.file_id,
-        edit: TextEdit::replace(param_range, String::from(self_param)),
-    });
+    let mut source_change = SourceChange::default();
+    source_change.extend(refs.references().iter().map(|(&file_id, references)| {
+        source_edit_from_references(sema, file_id, references, "self")
+    }));
+    source_change.insert_source_edit(
+        position.file_id,
+        TextEdit::replace(param_range, String::from(self_param)),
+    );
 
-    Ok(RangeInfo::new(range, SourceChange::from(edits)))
+    Ok(RangeInfo::new(range, source_change))
 }
 
 fn text_edit_from_self_param(
@@ -402,7 +396,7 @@ fn rename_self_to_param(
         .ok_or_else(|| format_err!("No surrounding method declaration found"))?;
     let search_range = fn_def.syntax().text_range();
 
-    let mut edits: Vec<SourceFileEdit> = vec![];
+    let mut source_change = SourceChange::default();
 
     for (idx, _) in text.match_indices("self") {
         let offset: TextSize = idx.try_into().unwrap();
@@ -416,18 +410,18 @@ fn rename_self_to_param(
             } else {
                 TextEdit::replace(usage.text_range(), String::from(new_name))
             };
-            edits.push(SourceFileEdit { file_id: position.file_id, edit });
+            source_change.insert_source_edit(position.file_id, edit);
         }
     }
 
-    if edits.len() > 1 && ident_kind == IdentifierKind::Underscore {
+    if source_change.source_file_edits.len() > 1 && ident_kind == IdentifierKind::Underscore {
         bail!("Cannot rename reference to `_` as it is being referenced multiple times");
     }
 
     let range = ast::SelfParam::cast(self_token.parent())
         .map_or(self_token.text_range(), |p| p.syntax().text_range());
 
-    Ok(RangeInfo::new(range, SourceChange::from(edits)))
+    Ok(RangeInfo::new(range, source_change))
 }
 
 fn rename_reference(
@@ -464,14 +458,12 @@ fn rename_reference(
         (IdentifierKind::Ident, _) | (IdentifierKind::Underscore, _) => mark::hit!(rename_ident),
     }
 
-    let edit = refs
-        .into_iter()
-        .map(|(file_id, references)| {
-            source_edit_from_references(sema, file_id, &references, new_name)
-        })
-        .collect::<Vec<_>>();
+    let mut source_change = SourceChange::default();
+    source_change.extend(refs.into_iter().map(|(file_id, references)| {
+        source_edit_from_references(sema, file_id, &references, new_name)
+    }));
 
-    Ok(RangeInfo::new(range, SourceChange::from(edit)))
+    Ok(RangeInfo::new(range, source_change))
 }
 
 #[cfg(test)]
@@ -494,8 +486,8 @@ mod tests {
                 let mut text_edit_builder = TextEdit::builder();
                 let mut file_id: Option<FileId> = None;
                 for edit in source_change.info.source_file_edits {
-                    file_id = Some(edit.file_id);
-                    for indel in edit.edit.into_iter() {
+                    file_id = Some(edit.0);
+                    for indel in edit.1.into_iter() {
                         text_edit_builder.replace(indel.delete, indel.insert);
                     }
                 }
@@ -895,21 +887,18 @@ mod foo$0;
                 RangeInfo {
                     range: 4..7,
                     info: SourceChange {
-                        source_file_edits: [
-                            SourceFileEdit {
-                                file_id: FileId(
-                                    1,
-                                ),
-                                edit: TextEdit {
-                                    indels: [
-                                        Indel {
-                                            insert: "foo2",
-                                            delete: 4..7,
-                                        },
-                                    ],
-                                },
+                        source_file_edits: {
+                            FileId(
+                                1,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "foo2",
+                                        delete: 4..7,
+                                    },
+                                ],
                             },
-                        ],
+                        },
                         file_system_edits: [
                             MoveFile {
                                 src: FileId(
@@ -950,34 +939,28 @@ use crate::foo$0::FooContent;
                 RangeInfo {
                     range: 11..14,
                     info: SourceChange {
-                        source_file_edits: [
-                            SourceFileEdit {
-                                file_id: FileId(
-                                    0,
-                                ),
-                                edit: TextEdit {
-                                    indels: [
-                                        Indel {
-                                            insert: "quux",
-                                            delete: 8..11,
-                                        },
-                                    ],
-                                },
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "quux",
+                                        delete: 8..11,
+                                    },
+                                ],
                             },
-                            SourceFileEdit {
-                                file_id: FileId(
-                                    2,
-                                ),
-                                edit: TextEdit {
-                                    indels: [
-                                        Indel {
-                                            insert: "quux",
-                                            delete: 11..14,
-                                        },
-                                    ],
-                                },
+                            FileId(
+                                2,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "quux",
+                                        delete: 11..14,
+                                    },
+                                ],
                             },
-                        ],
+                        },
                         file_system_edits: [
                             MoveFile {
                                 src: FileId(
@@ -1012,21 +995,18 @@ mod fo$0o;
                 RangeInfo {
                     range: 4..7,
                     info: SourceChange {
-                        source_file_edits: [
-                            SourceFileEdit {
-                                file_id: FileId(
-                                    0,
-                                ),
-                                edit: TextEdit {
-                                    indels: [
-                                        Indel {
-                                            insert: "foo2",
-                                            delete: 4..7,
-                                        },
-                                    ],
-                                },
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "foo2",
+                                        delete: 4..7,
+                                    },
+                                ],
                             },
-                        ],
+                        },
                         file_system_edits: [
                             MoveFile {
                                 src: FileId(
@@ -1062,21 +1042,18 @@ mod outer { mod fo$0o; }
                 RangeInfo {
                     range: 16..19,
                     info: SourceChange {
-                        source_file_edits: [
-                            SourceFileEdit {
-                                file_id: FileId(
-                                    0,
-                                ),
-                                edit: TextEdit {
-                                    indels: [
-                                        Indel {
-                                            insert: "bar",
-                                            delete: 16..19,
-                                        },
-                                    ],
-                                },
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "bar",
+                                        delete: 16..19,
+                                    },
+                                ],
                             },
-                        ],
+                        },
                         file_system_edits: [
                             MoveFile {
                                 src: FileId(
@@ -1135,34 +1112,28 @@ pub mod foo$0;
                 RangeInfo {
                     range: 8..11,
                     info: SourceChange {
-                        source_file_edits: [
-                            SourceFileEdit {
-                                file_id: FileId(
-                                    1,
-                                ),
-                                edit: TextEdit {
-                                    indels: [
-                                        Indel {
-                                            insert: "foo2",
-                                            delete: 8..11,
-                                        },
-                                    ],
-                                },
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "foo2",
+                                        delete: 27..30,
+                                    },
+                                ],
                             },
-                            SourceFileEdit {
-                                file_id: FileId(
-                                    0,
-                                ),
-                                edit: TextEdit {
-                                    indels: [
-                                        Indel {
-                                            insert: "foo2",
-                                            delete: 27..30,
-                                        },
-                                    ],
-                                },
+                            FileId(
+                                1,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "foo2",
+                                        delete: 8..11,
+                                    },
+                                ],
                             },
-                        ],
+                        },
                         file_system_edits: [
                             MoveFile {
                                 src: FileId(
diff --git a/crates/ide/src/typing.rs b/crates/ide/src/typing.rs
index 88c905003..e3c3aebac 100644
--- a/crates/ide/src/typing.rs
+++ b/crates/ide/src/typing.rs
@@ -15,8 +15,10 @@
 
 mod on_enter;
 
-use ide_db::base_db::{FilePosition, SourceDatabase};
-use ide_db::{source_change::SourceFileEdit, RootDatabase};
+use ide_db::{
+    base_db::{FilePosition, SourceDatabase},
+    RootDatabase,
+};
 use syntax::{
     algo::find_node_at_offset,
     ast::{self, edit::IndentLevel, AstToken},
@@ -56,7 +58,7 @@ pub(crate) fn on_char_typed(
     let file = &db.parse(position.file_id).tree();
     assert_eq!(file.syntax().text().char_at(position.offset), Some(char_typed));
     let edit = on_char_typed_inner(file, position.offset, char_typed)?;
-    Some(SourceFileEdit { file_id: position.file_id, edit }.into())
+    Some(SourceChange::from_text_edit(position.file_id, edit))
 }
 
 fn on_char_typed_inner(file: &SourceFile, offset: TextSize, char_typed: char) -> Option<TextEdit> {
diff --git a/crates/ide_db/src/source_change.rs b/crates/ide_db/src/source_change.rs
index 10c0abdac..b1f87731b 100644
--- a/crates/ide_db/src/source_change.rs
+++ b/crates/ide_db/src/source_change.rs
@@ -3,12 +3,19 @@
 //!
 //! It can be viewed as a dual for `AnalysisChange`.
 
+use std::{
+    collections::hash_map::Entry,
+    iter::{self, FromIterator},
+};
+
 use base_db::{AnchoredPathBuf, FileId};
+use rustc_hash::FxHashMap;
+use stdx::assert_never;
 use text_edit::TextEdit;
 
 #[derive(Default, Debug, Clone)]
 pub struct SourceChange {
-    pub source_file_edits: Vec<SourceFileEdit>,
+    pub source_file_edits: FxHashMap<FileId, TextEdit>,
     pub file_system_edits: Vec<FileSystemEdit>,
     pub is_snippet: bool,
 }
@@ -17,27 +24,50 @@ impl SourceChange {
     /// Creates a new SourceChange with the given label
     /// from the edits.
     pub fn from_edits(
-        source_file_edits: Vec<SourceFileEdit>,
+        source_file_edits: FxHashMap<FileId, TextEdit>,
         file_system_edits: Vec<FileSystemEdit>,
     ) -> Self {
         SourceChange { source_file_edits, file_system_edits, is_snippet: false }
     }
-}
 
-#[derive(Debug, Clone)]
-pub struct SourceFileEdit {
-    pub file_id: FileId,
-    pub edit: TextEdit,
+    pub fn from_text_edit(file_id: FileId, edit: TextEdit) -> Self {
+        SourceChange {
+            source_file_edits: FxHashMap::from_iter(iter::once((file_id, edit))),
+            ..Default::default()
+        }
+    }
+
+    pub fn insert_source_edit(&mut self, file_id: FileId, edit: TextEdit) {
+        match self.source_file_edits.entry(file_id) {
+            Entry::Occupied(mut entry) => {
+                assert_never!(
+                    entry.get_mut().union(edit).is_err(),
+                    "overlapping edits for same file"
+                );
+            }
+            Entry::Vacant(entry) => {
+                entry.insert(edit);
+            }
+        }
+    }
+
+    pub fn push_file_system_edit(&mut self, edit: FileSystemEdit) {
+        self.file_system_edits.push(edit);
+    }
+
+    pub fn get_source_edit(&self, file_id: FileId) -> Option<&TextEdit> {
+        self.source_file_edits.get(&file_id)
+    }
 }
 
-impl From<SourceFileEdit> for SourceChange {
-    fn from(edit: SourceFileEdit) -> SourceChange {
-        vec![edit].into()
+impl Extend<(FileId, TextEdit)> for SourceChange {
+    fn extend<T: IntoIterator<Item = (FileId, TextEdit)>>(&mut self, iter: T) {
+        iter.into_iter().for_each(|(file_id, edit)| self.insert_source_edit(file_id, edit));
     }
 }
 
-impl From<Vec<SourceFileEdit>> for SourceChange {
-    fn from(source_file_edits: Vec<SourceFileEdit>) -> SourceChange {
+impl From<FxHashMap<FileId, TextEdit>> for SourceChange {
+    fn from(source_file_edits: FxHashMap<FileId, TextEdit>) -> SourceChange {
         SourceChange { source_file_edits, file_system_edits: Vec::new(), is_snippet: false }
     }
 }
@@ -51,7 +81,7 @@ pub enum FileSystemEdit {
 impl From<FileSystemEdit> for SourceChange {
     fn from(edit: FileSystemEdit) -> SourceChange {
         SourceChange {
-            source_file_edits: Vec::new(),
+            source_file_edits: Default::default(),
             file_system_edits: vec![edit],
             is_snippet: false,
         }
diff --git a/crates/rust-analyzer/src/cli/ssr.rs b/crates/rust-analyzer/src/cli/ssr.rs
index a06631dac..bbb550ec9 100644
--- a/crates/rust-analyzer/src/cli/ssr.rs
+++ b/crates/rust-analyzer/src/cli/ssr.rs
@@ -12,10 +12,10 @@ pub fn apply_ssr_rules(rules: Vec<SsrRule>) -> Result<()> {
         match_finder.add_rule(rule)?;
     }
     let edits = match_finder.edits();
-    for edit in edits {
-        if let Some(path) = vfs.file_path(edit.file_id).as_path() {
-            let mut contents = db.file_text(edit.file_id).to_string();
-            edit.edit.apply(&mut contents);
+    for (file_id, edit) in edits {
+        if let Some(path) = vfs.file_path(file_id).as_path() {
+            let mut contents = db.file_text(file_id).to_string();
+            edit.apply(&mut contents);
             std::fs::write(path, contents)?;
         }
     }
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index dc81f55d6..1a4e0dd32 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -260,15 +260,15 @@ pub(crate) fn handle_on_type_formatting(
     }
 
     let edit = snap.analysis.on_char_typed(position, char_typed)?;
-    let mut edit = match edit {
+    let edit = match edit {
         Some(it) => it,
         None => return Ok(None),
     };
 
     // This should be a single-file edit
-    let edit = edit.source_file_edits.pop().unwrap();
+    let (_, edit) = edit.source_file_edits.into_iter().next().unwrap();
 
-    let change = to_proto::text_edit_vec(&line_index, line_endings, edit.edit);
+    let change = to_proto::text_edit_vec(&line_index, line_endings, edit);
     Ok(Some(change))
 }
 
@@ -463,9 +463,11 @@ pub(crate) fn handle_will_rename_files(
         .collect();
 
     // Drop file system edits since we're just renaming things on the same level
-    let edits = source_changes.into_iter().map(|it| it.source_file_edits).flatten().collect();
-    let source_change = SourceChange::from_edits(edits, Vec::new());
-
+    let mut source_changes = source_changes.into_iter();
+    let mut source_change = source_changes.next().unwrap_or_default();
+    source_change.file_system_edits.clear();
+    // no collect here because we want to merge text edits on same file ids
+    source_change.extend(source_changes.map(|it| it.source_file_edits).flatten());
     let workspace_edit = to_proto::workspace_edit(&snap, source_change)?;
     Ok(Some(workspace_edit))
 }
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index a7ff8975a..dc67d19a7 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -8,8 +8,7 @@ use ide::{
     Assist, AssistKind, CallInfo, CompletionItem, CompletionItemKind, Documentation, FileId,
     FileRange, FileSystemEdit, Fold, FoldKind, Highlight, HlMod, HlPunct, HlRange, HlTag, Indel,
     InlayHint, InlayKind, InsertTextFormat, LineIndex, Markup, NavigationTarget, ReferenceAccess,
-    RenameError, Runnable, Severity, SourceChange, SourceFileEdit, SymbolKind, TextEdit, TextRange,
-    TextSize,
+    RenameError, Runnable, Severity, SourceChange, SymbolKind, TextEdit, TextRange, TextSize,
 };
 use itertools::Itertools;
 
@@ -634,13 +633,13 @@ pub(crate) fn goto_definition_response(
 pub(crate) fn snippet_text_document_edit(
     snap: &GlobalStateSnapshot,
     is_snippet: bool,
-    source_file_edit: SourceFileEdit,
+    file_id: FileId,
+    edit: TextEdit,
 ) -> Result<lsp_ext::SnippetTextDocumentEdit> {
-    let text_document = optional_versioned_text_document_identifier(snap, source_file_edit.file_id);
-    let line_index = snap.analysis.file_line_index(source_file_edit.file_id)?;
-    let line_endings = snap.file_line_endings(source_file_edit.file_id);
-    let edits = source_file_edit
-        .edit
+    let text_document = optional_versioned_text_document_identifier(snap, file_id);
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    let line_endings = snap.file_line_endings(file_id);
+    let edits = edit
         .into_iter()
         .map(|it| snippet_text_edit(&line_index, line_endings, is_snippet, it))
         .collect();
@@ -699,8 +698,8 @@ pub(crate) fn snippet_workspace_edit(
         let ops = snippet_text_document_ops(snap, op);
         document_changes.extend_from_slice(&ops);
     }
-    for edit in source_change.source_file_edits {
-        let edit = snippet_text_document_edit(&snap, source_change.is_snippet, edit)?;
+    for (file_id, edit) in source_change.source_file_edits {
+        let edit = snippet_text_document_edit(&snap, source_change.is_snippet, file_id, edit)?;
         document_changes.push(lsp_ext::SnippetDocumentChangeOperation::Edit(edit));
     }
     let workspace_edit =
diff --git a/crates/ssr/src/lib.rs b/crates/ssr/src/lib.rs
index 747ce495d..a97fc8bca 100644
--- a/crates/ssr/src/lib.rs
+++ b/crates/ssr/src/lib.rs
@@ -75,10 +75,10 @@ pub use crate::matching::Match;
 use crate::matching::MatchFailureReason;
 use hir::Semantics;
 use ide_db::base_db::{FileId, FilePosition, FileRange};
-use ide_db::source_change::SourceFileEdit;
 use resolving::ResolvedRule;
 use rustc_hash::FxHashMap;
 use syntax::{ast, AstNode, SyntaxNode, TextRange};
+use text_edit::TextEdit;
 
 // A structured search replace rule. Create by calling `parse` on a str.
 #[derive(Debug)]
@@ -159,7 +159,7 @@ impl<'db> MatchFinder<'db> {
     }
 
     /// Finds matches for all added rules and returns edits for all found matches.
-    pub fn edits(&self) -> Vec<SourceFileEdit> {
+    pub fn edits(&self) -> FxHashMap<FileId, TextEdit> {
         use ide_db::base_db::SourceDatabaseExt;
         let mut matches_by_file = FxHashMap::default();
         for m in self.matches().matches {
@@ -169,13 +169,19 @@ impl<'db> MatchFinder<'db> {
                 .matches
                 .push(m);
         }
-        let mut edits = vec![];
-        for (file_id, matches) in matches_by_file {
-            let edit =
-                replacing::matches_to_edit(&matches, &self.sema.db.file_text(file_id), &self.rules);
-            edits.push(SourceFileEdit { file_id, edit });
-        }
-        edits
+        matches_by_file
+            .into_iter()
+            .map(|(file_id, matches)| {
+                (
+                    file_id,
+                    replacing::matches_to_edit(
+                        &matches,
+                        &self.sema.db.file_text(file_id),
+                        &self.rules,
+                    ),
+                )
+            })
+            .collect()
     }
 
     /// Adds a search pattern. For use if you intend to only call `find_matches_in_file`. If you
diff --git a/crates/ssr/src/matching.rs b/crates/ssr/src/matching.rs
index 6cf831431..42d313f91 100644
--- a/crates/ssr/src/matching.rs
+++ b/crates/ssr/src/matching.rs
@@ -810,9 +810,9 @@ mod tests {
 
         let edits = match_finder.edits();
         assert_eq!(edits.len(), 1);
-        let edit = &edits[0];
+        let edit = &edits[&position.file_id];
         let mut after = input.to_string();
-        edit.edit.apply(&mut after);
+        edit.apply(&mut after);
         assert_eq!(after, "fn foo() {} fn bar() {} fn main() { bar(1+2); }");
     }
 }
diff --git a/crates/ssr/src/tests.rs b/crates/ssr/src/tests.rs
index d6918c22d..a3ea44f23 100644
--- a/crates/ssr/src/tests.rs
+++ b/crates/ssr/src/tests.rs
@@ -103,11 +103,10 @@ fn assert_ssr_transforms(rules: &[&str], input: &str, expected: Expect) {
     if edits.is_empty() {
         panic!("No edits were made");
     }
-    assert_eq!(edits[0].file_id, position.file_id);
     // Note, db.file_text is not necessarily the same as `input`, since fixture parsing alters
     // stuff.
     let mut actual = db.file_text(position.file_id).to_string();
-    edits[0].edit.apply(&mut actual);
+    edits[&position.file_id].apply(&mut actual);
     expected.assert_eq(&actual);
 }
 
diff --git a/crates/stdx/src/macros.rs b/crates/stdx/src/macros.rs
index 263b938e3..4f5c6100d 100644
--- a/crates/stdx/src/macros.rs
+++ b/crates/stdx/src/macros.rs
@@ -66,7 +66,7 @@ macro_rules! impl_from {
 /// Shamelessly stolen from: https://www.sqlite.org/assert.html
 #[macro_export]
 macro_rules! assert_never {
-    ($cond:expr) => { $crate::assert_always!($cond, "") };
+    ($cond:expr) => { $crate::assert_never!($cond, "") };
     ($cond:expr, $($fmt:tt)*) => {{
         let value = $cond;
         if value {