internal: flatten module hierarchy

It seems that any crate can be made better by flattening the modules
down to a single layer?

1 files changed, 1789 insertions, 0 deletions

diff --git a/crates/ide/src/rename.rs b/crates/ide/src/rename.rs
new file mode 100644
index 000000000..41689a939
--- /dev/null
+++ b/crates/ide/src/rename.rs
@@ -0,0 +1,1789 @@
+//! Renaming functionality.
+//!
+//! This is mostly front-end for [`ide_db::rename`], but it also includes the
+//! tests. This module also implements a couple of magic tricks, like renaming
+//! `self` and to `self` (to switch between associated function and method).
+use hir::{AsAssocItem, InFile, Semantics};
+use ide_db::{
+    base_db::FileId,
+    defs::{Definition, NameClass, NameRefClass},
+    rename::{bail, format_err, source_edit_from_references, IdentifierKind},
+    RootDatabase,
+};
+use stdx::never;
+use syntax::{ast, AstNode, SyntaxNode};
+
+use text_edit::TextEdit;
+
+use crate::{FilePosition, RangeInfo, SourceChange};
+
+pub use ide_db::rename::RenameError;
+
+type RenameResult<T> = Result<T, RenameError>;
+
+/// Prepares a rename. The sole job of this function is to return the TextRange of the thing that is
+/// being targeted for a rename.
+pub(crate) fn prepare_rename(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> RenameResult<RangeInfo<()>> {
+    let sema = Semantics::new(db);
+    let source_file = sema.parse(position.file_id);
+    let syntax = source_file.syntax();
+
+    let def = find_definition(&sema, syntax, position)?;
+    let frange =
+        def.rename_range(&sema).ok_or_else(|| format_err!("No references found at position"))?;
+    Ok(RangeInfo::new(frange.range, ()))
+}
+
+// Feature: Rename
+//
+// Renames the item below the cursor and all of its references
+//
+// |===
+// | Editor  | Shortcut
+//
+// | VS Code | kbd:[F2]
+// |===
+//
+// image::https://user-images.githubusercontent.com/48062697/113065582-055aae80-91b1-11eb-8ade-2b58e6d81883.gif[]
+pub(crate) fn rename(
+    db: &RootDatabase,
+    position: FilePosition,
+    new_name: &str,
+) -> RenameResult<SourceChange> {
+    let sema = Semantics::new(db);
+    rename_with_semantics(&sema, position, new_name)
+}
+
+pub(crate) fn rename_with_semantics(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+    new_name: &str,
+) -> RenameResult<SourceChange> {
+    let source_file = sema.parse(position.file_id);
+    let syntax = source_file.syntax();
+
+    let def = find_definition(sema, syntax, position)?;
+
+    if let Definition::Local(local) = def {
+        if let Some(self_param) = local.as_self_param(sema.db) {
+            cov_mark::hit!(rename_self_to_param);
+            return rename_self_to_param(sema, local, self_param, new_name);
+        }
+        if new_name == "self" {
+            cov_mark::hit!(rename_to_self);
+            return rename_to_self(sema, local);
+        }
+    }
+
+    def.rename(sema, new_name)
+}
+
+/// Called by the client when it is about to rename a file.
+pub(crate) fn will_rename_file(
+    db: &RootDatabase,
+    file_id: FileId,
+    new_name_stem: &str,
+) -> Option<SourceChange> {
+    let sema = Semantics::new(db);
+    let module = sema.to_module_def(file_id)?;
+    let def = Definition::ModuleDef(module.into());
+    let mut change = def.rename(&sema, new_name_stem).ok()?;
+    change.file_system_edits.clear();
+    Some(change)
+}
+
+fn find_definition(
+    sema: &Semantics<RootDatabase>,
+    syntax: &SyntaxNode,
+    position: FilePosition,
+) -> RenameResult<Definition> {
+    match sema
+        .find_node_at_offset_with_descend(syntax, position.offset)
+        .ok_or_else(|| format_err!("No references found at position"))?
+    {
+        // renaming aliases would rename the item being aliased as the HIR doesn't track aliases yet
+        ast::NameLike::Name(name)
+            if name.syntax().parent().map_or(false, |it| ast::Rename::can_cast(it.kind())) =>
+        {
+            bail!("Renaming aliases is currently unsupported")
+        }
+        ast::NameLike::Name(name) => {
+            NameClass::classify(sema, &name).map(|class| class.referenced_or_defined(sema.db))
+        }
+        ast::NameLike::NameRef(name_ref) => {
+            if let Some(def) =
+                NameRefClass::classify(sema, &name_ref).map(|class| class.referenced(sema.db))
+            {
+                // if the name differs from the definitions name it has to be an alias
+                if def.name(sema.db).map_or(false, |it| it.to_string() != name_ref.text()) {
+                    bail!("Renaming aliases is currently unsupported");
+                }
+                Some(def)
+            } else {
+                None
+            }
+        }
+        ast::NameLike::Lifetime(lifetime) => NameRefClass::classify_lifetime(sema, &lifetime)
+            .map(|class| NameRefClass::referenced(class, sema.db))
+            .or_else(|| {
+                NameClass::classify_lifetime(sema, &lifetime)
+                    .map(|it| it.referenced_or_defined(sema.db))
+            }),
+    }
+    .ok_or_else(|| format_err!("No references found at position"))
+}
+
+fn rename_to_self(sema: &Semantics<RootDatabase>, local: hir::Local) -> RenameResult<SourceChange> {
+    if never!(local.is_self(sema.db)) {
+        bail!("rename_to_self invoked on self");
+    }
+
+    let fn_def = match local.parent(sema.db) {
+        hir::DefWithBody::Function(func) => func,
+        _ => bail!("Cannot rename local to self outside of function"),
+    };
+
+    if let Some(_) = fn_def.self_param(sema.db) {
+        bail!("Method already has a self parameter");
+    }
+
+    let params = fn_def.assoc_fn_params(sema.db);
+    let first_param = params
+        .first()
+        .ok_or_else(|| format_err!("Cannot rename local to self unless it is a parameter"))?;
+    if first_param.as_local(sema.db) != local {
+        bail!("Only the first parameter may be renamed to self");
+    }
+
+    let assoc_item = fn_def
+        .as_assoc_item(sema.db)
+        .ok_or_else(|| format_err!("Cannot rename parameter to self for free function"))?;
+    let impl_ = match assoc_item.container(sema.db) {
+        hir::AssocItemContainer::Trait(_) => {
+            bail!("Cannot rename parameter to self for trait functions");
+        }
+        hir::AssocItemContainer::Impl(impl_) => impl_,
+    };
+    let first_param_ty = first_param.ty();
+    let impl_ty = impl_.self_ty(sema.db);
+    let (ty, self_param) = if impl_ty.remove_ref().is_some() {
+        // if the impl is a ref to the type we can just match the `&T` with self directly
+        (first_param_ty.clone(), "self")
+    } else {
+        first_param_ty.remove_ref().map_or((first_param_ty.clone(), "self"), |ty| {
+            (ty, if first_param_ty.is_mutable_reference() { "&mut self" } else { "&self" })
+        })
+    };
+
+    if ty != impl_ty {
+        bail!("Parameter type differs from impl block type");
+    }
+
+    let InFile { file_id, value: param_source } =
+        first_param.source(sema.db).ok_or_else(|| format_err!("No source for parameter found"))?;
+
+    let def = Definition::Local(local);
+    let usages = def.usages(sema).all();
+    let mut source_change = SourceChange::default();
+    source_change.extend(usages.iter().map(|(&file_id, references)| {
+        (file_id, source_edit_from_references(references, def, "self"))
+    }));
+    source_change.insert_source_edit(
+        file_id.original_file(sema.db),
+        TextEdit::replace(param_source.syntax().text_range(), String::from(self_param)),
+    );
+    Ok(source_change)
+}
+
+fn rename_self_to_param(
+    sema: &Semantics<RootDatabase>,
+    local: hir::Local,
+    self_param: hir::SelfParam,
+    new_name: &str,
+) -> RenameResult<SourceChange> {
+    if new_name == "self" {
+        // Let's do nothing rather than complain.
+        cov_mark::hit!(rename_self_to_self);
+        return Ok(SourceChange::default());
+    }
+
+    let identifier_kind = IdentifierKind::classify(new_name)?;
+
+    let InFile { file_id, value: self_param } =
+        self_param.source(sema.db).ok_or_else(|| format_err!("cannot find function source"))?;
+
+    let def = Definition::Local(local);
+    let usages = def.usages(sema).all();
+    let edit = text_edit_from_self_param(&self_param, new_name)
+        .ok_or_else(|| format_err!("No target type found"))?;
+    if usages.len() > 1 && identifier_kind == IdentifierKind::Underscore {
+        bail!("Cannot rename reference to `_` as it is being referenced multiple times");
+    }
+    let mut source_change = SourceChange::default();
+    source_change.insert_source_edit(file_id.original_file(sema.db), edit);
+    source_change.extend(usages.iter().map(|(&file_id, references)| {
+        (file_id, source_edit_from_references(references, def, new_name))
+    }));
+    Ok(source_change)
+}
+
+fn text_edit_from_self_param(self_param: &ast::SelfParam, new_name: &str) -> Option<TextEdit> {
+    fn target_type_name(impl_def: &ast::Impl) -> Option<String> {
+        if let Some(ast::Type::PathType(p)) = impl_def.self_ty() {
+            return Some(p.path()?.segment()?.name_ref()?.text().to_string());
+        }
+        None
+    }
+
+    let impl_def = self_param.syntax().ancestors().find_map(ast::Impl::cast)?;
+    let type_name = target_type_name(&impl_def)?;
+
+    let mut replacement_text = String::from(new_name);
+    replacement_text.push_str(": ");
+    match (self_param.amp_token(), self_param.mut_token()) {
+        (Some(_), None) => replacement_text.push('&'),
+        (Some(_), Some(_)) => replacement_text.push_str("&mut "),
+        (_, _) => (),
+    };
+    replacement_text.push_str(type_name.as_str());
+
+    Some(TextEdit::replace(self_param.syntax().text_range(), replacement_text))
+}
+
+#[cfg(test)]
+mod tests {
+    use expect_test::{expect, Expect};
+    use stdx::trim_indent;
+    use test_utils::assert_eq_text;
+    use text_edit::TextEdit;
+
+    use crate::{fixture, FileId};
+
+    use super::{RangeInfo, RenameError};
+
+    fn check(new_name: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+        let ra_fixture_after = &trim_indent(ra_fixture_after);
+        let (analysis, position) = fixture::position(ra_fixture_before);
+        let rename_result = analysis
+            .rename(position, new_name)
+            .unwrap_or_else(|err| panic!("Rename to '{}' was cancelled: {}", new_name, err));
+        match rename_result {
+            Ok(source_change) => {
+                let mut text_edit_builder = TextEdit::builder();
+                let mut file_id: Option<FileId> = None;
+                for edit in source_change.source_file_edits {
+                    file_id = Some(edit.0);
+                    for indel in edit.1.into_iter() {
+                        text_edit_builder.replace(indel.delete, indel.insert);
+                    }
+                }
+                if let Some(file_id) = file_id {
+                    let mut result = analysis.file_text(file_id).unwrap().to_string();
+                    text_edit_builder.finish().apply(&mut result);
+                    assert_eq_text!(ra_fixture_after, &*result);
+                }
+            }
+            Err(err) => {
+                if ra_fixture_after.starts_with("error:") {
+                    let error_message = ra_fixture_after
+                        .chars()
+                        .into_iter()
+                        .skip("error:".len())
+                        .collect::<String>();
+                    assert_eq!(error_message.trim(), err.to_string());
+                    return;
+                } else {
+                    panic!("Rename to '{}' failed unexpectedly: {}", new_name, err)
+                }
+            }
+        };
+    }
+
+    fn check_expect(new_name: &str, ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = fixture::position(ra_fixture);
+        let source_change =
+            analysis.rename(position, new_name).unwrap().expect("Expect returned a RenameError");
+        expect.assert_debug_eq(&source_change)
+    }
+
+    fn check_prepare(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = fixture::position(ra_fixture);
+        let result = analysis
+            .prepare_rename(position)
+            .unwrap_or_else(|err| panic!("PrepareRename was cancelled: {}", err));
+        match result {
+            Ok(RangeInfo { range, info: () }) => {
+                let source = analysis.file_text(position.file_id).unwrap();
+                expect.assert_eq(&format!("{:?}: {}", range, &source[range]))
+            }
+            Err(RenameError(err)) => expect.assert_eq(&err),
+        };
+    }
+
+    #[test]
+    fn test_prepare_rename_namelikes() {
+        check_prepare(r"fn name$0<'lifetime>() {}", expect![[r#"3..7: name"#]]);
+        check_prepare(r"fn name<'lifetime$0>() {}", expect![[r#"8..17: 'lifetime"#]]);
+        check_prepare(r"fn name<'lifetime>() { name$0(); }", expect![[r#"3..7: name"#]]);
+    }
+
+    #[test]
+    fn test_prepare_rename_in_macro() {
+        check_prepare(
+            r"macro_rules! foo {
+    ($ident:ident) => {
+        pub struct $ident;
+    }
+}
+foo!(Foo$0);",
+            expect![[r#"83..86: Foo"#]],
+        );
+    }
+
+    #[test]
+    fn test_prepare_rename_keyword() {
+        check_prepare(r"struct$0 Foo;", expect![[r#"No references found at position"#]]);
+    }
+
+    #[test]
+    fn test_prepare_rename_tuple_field() {
+        check_prepare(
+            r#"
+struct Foo(i32);
+
+fn baz() {
+    let mut x = Foo(4);
+    x.0$0 = 5;
+}
+"#,
+            expect![[r#"No references found at position"#]],
+        );
+    }
+
+    #[test]
+    fn test_prepare_rename_builtin() {
+        check_prepare(
+            r#"
+fn foo() {
+    let x: i32$0 = 0;
+}
+"#,
+            expect![[r#"No references found at position"#]],
+        );
+    }
+
+    #[test]
+    fn test_prepare_rename_self() {
+        check_prepare(
+            r#"
+struct Foo {}
+
+impl Foo {
+    fn foo(self) -> Self$0 {
+        self
+    }
+}
+"#,
+            expect![[r#"No references found at position"#]],
+        );
+    }
+
+    #[test]
+    fn test_rename_to_underscore() {
+        check("_", r#"fn main() { let i$0 = 1; }"#, r#"fn main() { let _ = 1; }"#);
+    }
+
+    #[test]
+    fn test_rename_to_raw_identifier() {
+        check("r#fn", r#"fn main() { let i$0 = 1; }"#, r#"fn main() { let r#fn = 1; }"#);
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier1() {
+        check(
+            "invalid!",
+            r#"fn main() { let i$0 = 1; }"#,
+            "error: Invalid name `invalid!`: not an identifier",
+        );
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier2() {
+        check(
+            "multiple tokens",
+            r#"fn main() { let i$0 = 1; }"#,
+            "error: Invalid name `multiple tokens`: not an identifier",
+        );
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier3() {
+        check(
+            "let",
+            r#"fn main() { let i$0 = 1; }"#,
+            "error: Invalid name `let`: not an identifier",
+        );
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier_lifetime() {
+        cov_mark::check!(rename_not_an_ident_ref);
+        check(
+            "'foo",
+            r#"fn main() { let i$0 = 1; }"#,
+            "error: Invalid name `'foo`: not an identifier",
+        );
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier_lifetime2() {
+        cov_mark::check!(rename_not_a_lifetime_ident_ref);
+        check(
+            "foo",
+            r#"fn main<'a>(_: &'a$0 ()) {}"#,
+            "error: Invalid name `foo`: not a lifetime identifier",
+        );
+    }
+
+    #[test]
+    fn test_rename_to_underscore_invalid() {
+        cov_mark::check!(rename_underscore_multiple);
+        check(
+            "_",
+            r#"fn main(foo$0: ()) {foo;}"#,
+            "error: Cannot rename reference to `_` as it is being referenced multiple times",
+        );
+    }
+
+    #[test]
+    fn test_rename_mod_invalid() {
+        check(
+            "'foo",
+            r#"mod foo$0 {}"#,
+            "error: Invalid name `'foo`: cannot rename module to 'foo",
+        );
+    }
+
+    #[test]
+    fn test_rename_for_local() {
+        check(
+            "k",
+            r#"
+fn main() {
+    let mut i = 1;
+    let j = 1;
+    i = i$0 + j;
+
+    { i = 0; }
+
+    i = 5;
+}
+"#,
+            r#"
+fn main() {
+    let mut k = 1;
+    let j = 1;
+    k = k + j;
+
+    { k = 0; }
+
+    k = 5;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_unresolved_reference() {
+        check(
+            "new_name",
+            r#"fn main() { let _ = unresolved_ref$0; }"#,
+            "error: No references found at position",
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_args() {
+        check(
+            "b",
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let a$0 = "test";
+    foo!(a);
+}
+"#,
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let b = "test";
+    foo!(b);
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_args_rev() {
+        check(
+            "b",
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let a = "test";
+    foo!(a$0);
+}
+"#,
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let b = "test";
+    foo!(b);
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_define_fn() {
+        check(
+            "bar",
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(foo);
+fn main() {
+    fo$0o();
+}
+"#,
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(bar);
+fn main() {
+    bar();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_macro_define_fn_rev() {
+        check(
+            "bar",
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(fo$0o);
+fn main() {
+    foo();
+}
+"#,
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(bar);
+fn main() {
+    bar();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_for_param_inside() {
+        check("j", r#"fn foo(i : u32) -> u32 { i$0 }"#, r#"fn foo(j : u32) -> u32 { j }"#);
+    }
+
+    #[test]
+    fn test_rename_refs_for_fn_param() {
+        check("j", r#"fn foo(i$0 : u32) -> u32 { i }"#, r#"fn foo(j : u32) -> u32 { j }"#);
+    }
+
+    #[test]
+    fn test_rename_for_mut_param() {
+        check("j", r#"fn foo(mut i$0 : u32) -> u32 { i }"#, r#"fn foo(mut j : u32) -> u32 { j }"#);
+    }
+
+    #[test]
+    fn test_rename_struct_field() {
+        check(
+            "j",
+            r#"
+struct Foo { i$0: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { i: i }
+    }
+}
+"#,
+            r#"
+struct Foo { j: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { j: i }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_field_in_field_shorthand() {
+        cov_mark::check!(test_rename_field_in_field_shorthand);
+        check(
+            "j",
+            r#"
+struct Foo { i$0: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+            r#"
+struct Foo { j: i32 }
+
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { j: i }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_local_in_field_shorthand() {
+        cov_mark::check!(test_rename_local_in_field_shorthand);
+        check(
+            "j",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn new(i$0: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn new(j: i32) -> Self {
+        Self { i: j }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_field_shorthand_correct_struct() {
+        check(
+            "j",
+            r#"
+struct Foo { i$0: i32 }
+struct Bar { i: i32 }
+
+impl Bar {
+    fn new(i: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+            r#"
+struct Foo { j: i32 }
+struct Bar { i: i32 }
+
+impl Bar {
+    fn new(i: i32) -> Self {
+        Self { i }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_shadow_local_for_struct_shorthand() {
+        check(
+            "j",
+            r#"
+struct Foo { i: i32 }
+
+fn baz(i$0: i32) -> Self {
+     let x = Foo { i };
+     {
+         let i = 0;
+         Foo { i }
+     }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+fn baz(j: i32) -> Self {
+     let x = Foo { i: j };
+     {
+         let i = 0;
+         Foo { i }
+     }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_mod() {
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod bar;
+
+//- /bar.rs
+mod foo$0;
+
+//- /bar/foo.rs
+// empty
+"#,
+            expect![[r#"
+                SourceChange {
+                    source_file_edits: {
+                        FileId(
+                            1,
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "foo2",
+                                    delete: 4..7,
+                                },
+                            ],
+                        },
+                    },
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                2,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
+                                    2,
+                                ),
+                                path: "foo2.rs",
+                            },
+                        },
+                    ],
+                    is_snippet: false,
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_rename_mod_in_use_tree() {
+        check_expect(
+            "quux",
+            r#"
+//- /main.rs
+pub mod foo;
+pub mod bar;
+fn main() {}
+
+//- /foo.rs
+pub struct FooContent;
+
+//- /bar.rs
+use crate::foo$0::FooContent;
+"#,
+            expect![[r#"
+                SourceChange {
+                    source_file_edits: {
+                        FileId(
+                            0,
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "quux",
+                                    delete: 8..11,
+                                },
+                            ],
+                        },
+                        FileId(
+                            2,
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "quux",
+                                    delete: 11..14,
+                                },
+                            ],
+                        },
+                    },
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                1,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
+                                    1,
+                                ),
+                                path: "quux.rs",
+                            },
+                        },
+                    ],
+                    is_snippet: false,
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_rename_mod_in_dir() {
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod fo$0o;
+//- /foo/mod.rs
+// empty
+"#,
+            expect![[r#"
+                SourceChange {
+                    source_file_edits: {
+                        FileId(
+                            0,
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "foo2",
+                                    delete: 4..7,
+                                },
+                            ],
+                        },
+                    },
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                1,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
+                                    1,
+                                ),
+                                path: "../foo2/mod.rs",
+                            },
+                        },
+                    ],
+                    is_snippet: false,
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_rename_unusually_nested_mod() {
+        check_expect(
+            "bar",
+            r#"
+//- /lib.rs
+mod outer { mod fo$0o; }
+
+//- /outer/foo.rs
+// empty
+"#,
+            expect![[r#"
+                SourceChange {
+                    source_file_edits: {
+                        FileId(
+                            0,
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "bar",
+                                    delete: 16..19,
+                                },
+                            ],
+                        },
+                    },
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                1,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
+                                    1,
+                                ),
+                                path: "bar.rs",
+                            },
+                        },
+                    ],
+                    is_snippet: false,
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_module_rename_in_path() {
+        check(
+            "baz",
+            r#"
+mod $0foo { pub fn bar() {} }
+
+fn main() { foo::bar(); }
+"#,
+            r#"
+mod baz { pub fn bar() {} }
+
+fn main() { baz::bar(); }
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_mod_filename_and_path() {
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod bar;
+fn f() {
+    bar::foo::fun()
+}
+
+//- /bar.rs
+pub mod foo$0;
+
+//- /bar/foo.rs
+// pub fn fun() {}
+"#,
+            expect![[r#"
+                SourceChange {
+                    source_file_edits: {
+                        FileId(
+                            0,
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "foo2",
+                                    delete: 27..30,
+                                },
+                            ],
+                        },
+                        FileId(
+                            1,
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "foo2",
+                                    delete: 8..11,
+                                },
+                            ],
+                        },
+                    },
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                2,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
+                                    2,
+                                ),
+                                path: "foo2.rs",
+                            },
+                        },
+                    ],
+                    is_snippet: false,
+                }
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_enum_variant_from_module_1() {
+        cov_mark::check!(rename_non_local);
+        check(
+            "Baz",
+            r#"
+mod foo {
+    pub enum Foo { Bar$0 }
+}
+
+fn func(f: foo::Foo) {
+    match f {
+        foo::Foo::Bar => {}
+    }
+}
+"#,
+            r#"
+mod foo {
+    pub enum Foo { Baz }
+}
+
+fn func(f: foo::Foo) {
+    match f {
+        foo::Foo::Baz => {}
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_enum_variant_from_module_2() {
+        check(
+            "baz",
+            r#"
+mod foo {
+    pub struct Foo { pub bar$0: uint }
+}
+
+fn foo(f: foo::Foo) {
+    let _ = f.bar;
+}
+"#,
+            r#"
+mod foo {
+    pub struct Foo { pub baz: uint }
+}
+
+fn foo(f: foo::Foo) {
+    let _ = f.baz;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self() {
+        cov_mark::check!(rename_to_self);
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo$0: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(&mut self) -> i32 {
+        self.i
+    }
+}
+"#,
+        );
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo$0: Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(self) -> i32 {
+        self.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self_error_no_impl() {
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+
+fn f(foo$0: &mut Foo) -> i32 {
+    foo.i
+}
+"#,
+            "error: Cannot rename parameter to self for free function",
+        );
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+struct Bar;
+
+impl Bar {
+    fn f(foo$0: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            "error: Parameter type differs from impl block type",
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self_error_not_first() {
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+impl Foo {
+    fn f(x: (), foo$0: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            "error: Only the first parameter may be renamed to self",
+        );
+    }
+
+    #[test]
+    fn test_parameter_to_self_impl_ref() {
+        check(
+            "self",
+            r#"
+struct Foo { i: i32 }
+impl &Foo {
+    fn f(foo$0: &Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+impl &Foo {
+    fn f(self) -> i32 {
+        self.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_self_to_parameter() {
+        check(
+            "foo",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(&mut $0self) -> i32 {
+        self.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo: &mut Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_owned_self_to_parameter() {
+        cov_mark::check!(rename_self_to_param);
+        check(
+            "foo",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f($0self) -> i32 {
+        self.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo: Foo) -> i32 {
+        foo.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_self_in_path_to_parameter() {
+        check(
+            "foo",
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(&self) -> i32 {
+        let self_var = 1;
+        self$0.i
+    }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+impl Foo {
+    fn f(foo: &Foo) -> i32 {
+        let self_var = 1;
+        foo.i
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_field_put_init_shorthand() {
+        cov_mark::check!(test_rename_field_put_init_shorthand);
+        check(
+            "bar",
+            r#"
+struct Foo { i$0: i32 }
+
+fn foo(bar: i32) -> Foo {
+    Foo { i: bar }
+}
+"#,
+            r#"
+struct Foo { bar: i32 }
+
+fn foo(bar: i32) -> Foo {
+    Foo { bar }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_local_put_init_shorthand() {
+        cov_mark::check!(test_rename_local_put_init_shorthand);
+        check(
+            "i",
+            r#"
+struct Foo { i: i32 }
+
+fn foo(bar$0: i32) -> Foo {
+    Foo { i: bar }
+}
+"#,
+            r#"
+struct Foo { i: i32 }
+
+fn foo(i: i32) -> Foo {
+    Foo { i }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_struct_field_pat_into_shorthand() {
+        cov_mark::check!(test_rename_field_put_init_shorthand_pat);
+        check(
+            "baz",
+            r#"
+struct Foo { i$0: i32 }
+
+fn foo(foo: Foo) {
+    let Foo { i: ref baz @ qux } = foo;
+    let _ = qux;
+}
+"#,
+            r#"
+struct Foo { baz: i32 }
+
+fn foo(foo: Foo) {
+    let Foo { ref baz @ qux } = foo;
+    let _ = qux;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_binding_in_destructure_pat() {
+        let expected_fixture = r#"
+struct Foo {
+    i: i32,
+}
+
+fn foo(foo: Foo) {
+    let Foo { i: bar } = foo;
+    let _ = bar;
+}
+"#;
+        check(
+            "bar",
+            r#"
+struct Foo {
+    i: i32,
+}
+
+fn foo(foo: Foo) {
+    let Foo { i: b } = foo;
+    let _ = b$0;
+}
+"#,
+            expected_fixture,
+        );
+        check(
+            "bar",
+            r#"
+struct Foo {
+    i: i32,
+}
+
+fn foo(foo: Foo) {
+    let Foo { i } = foo;
+    let _ = i$0;
+}
+"#,
+            expected_fixture,
+        );
+    }
+
+    #[test]
+    fn test_rename_binding_in_destructure_param_pat() {
+        check(
+            "bar",
+            r#"
+struct Foo {
+    i: i32
+}
+
+fn foo(Foo { i }: foo) -> i32 {
+    i$0
+}
+"#,
+            r#"
+struct Foo {
+    i: i32
+}
+
+fn foo(Foo { i: bar }: foo) -> i32 {
+    bar
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_struct_field_complex_ident_pat() {
+        check(
+            "baz",
+            r#"
+struct Foo { i$0: i32 }
+
+fn foo(foo: Foo) {
+    let Foo { ref i } = foo;
+}
+"#,
+            r#"
+struct Foo { baz: i32 }
+
+fn foo(foo: Foo) {
+    let Foo { baz: ref i } = foo;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_lifetimes() {
+        cov_mark::check!(rename_lifetime);
+        check(
+            "'yeeee",
+            r#"
+trait Foo<'a> {
+    fn foo() -> &'a ();
+}
+impl<'a> Foo<'a> for &'a () {
+    fn foo() -> &'a$0 () {
+        unimplemented!()
+    }
+}
+"#,
+            r#"
+trait Foo<'a> {
+    fn foo() -> &'a ();
+}
+impl<'yeeee> Foo<'yeeee> for &'yeeee () {
+    fn foo() -> &'yeeee () {
+        unimplemented!()
+    }
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_rename_bind_pat() {
+        check(
+            "new_name",
+            r#"
+fn main() {
+    enum CustomOption<T> {
+        None,
+        Some(T),
+    }
+
+    let test_variable = CustomOption::Some(22);
+
+    match test_variable {
+        CustomOption::Some(foo$0) if foo == 11 => {}
+        _ => (),
+    }
+}"#,
+            r#"
+fn main() {
+    enum CustomOption<T> {
+        None,
+        Some(T),
+    }
+
+    let test_variable = CustomOption::Some(22);
+
+    match test_variable {
+        CustomOption::Some(new_name) if new_name == 11 => {}
+        _ => (),
+    }
+}"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_label() {
+        check(
+            "'foo",
+            r#"
+fn foo<'a>() -> &'a () {
+    'a: {
+        'b: loop {
+            break 'a$0;
+        }
+    }
+}
+"#,
+            r#"
+fn foo<'a>() -> &'a () {
+    'foo: {
+        'b: loop {
+            break 'foo;
+        }
+    }
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_self_to_self() {
+        cov_mark::check!(rename_self_to_self);
+        check(
+            "self",
+            r#"
+struct Foo;
+impl Foo {
+    fn foo(self$0) {}
+}
+"#,
+            r#"
+struct Foo;
+impl Foo {
+    fn foo(self) {}
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_rename_field_in_pat_in_macro_doesnt_shorthand() {
+        // ideally we would be able to make this emit a short hand, but I doubt this is easily possible
+        check(
+            "baz",
+            r#"
+macro_rules! foo {
+    ($pattern:pat) => {
+        let $pattern = loop {};
+    };
+}
+struct Foo {
+    bar$0: u32,
+}
+fn foo() {
+    foo!(Foo { bar: baz });
+}
+"#,
+            r#"
+macro_rules! foo {
+    ($pattern:pat) => {
+        let $pattern = loop {};
+    };
+}
+struct Foo {
+    baz: u32,
+}
+fn foo() {
+    foo!(Foo { baz: baz });
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_rename_tuple_field() {
+        check(
+            "foo",
+            r#"
+struct Foo(i32);
+
+fn baz() {
+    let mut x = Foo(4);
+    x.0$0 = 5;
+}
+"#,
+            "error: No identifier available to rename",
+        );
+    }
+
+    #[test]
+    fn test_rename_builtin() {
+        check(
+            "foo",
+            r#"
+fn foo() {
+    let x: i32$0 = 0;
+}
+"#,
+            "error: Cannot rename builtin type",
+        );
+    }
+
+    #[test]
+    fn test_rename_self() {
+        check(
+            "foo",
+            r#"
+struct Foo {}
+
+impl Foo {
+    fn foo(self) -> Self$0 {
+        self
+    }
+}
+"#,
+            "error: Cannot rename `Self`",
+        );
+    }
+
+    #[test]
+    fn test_rename_ignores_self_ty() {
+        check(
+            "Fo0",
+            r#"
+struct $0Foo;
+
+impl Foo where Self: {}
+"#,
+            r#"
+struct Fo0;
+
+impl Fo0 where Self: {}
+"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_fails_on_aliases() {
+        check(
+            "Baz",
+            r#"
+struct Foo;
+use Foo as Bar$0;
+"#,
+            "error: Renaming aliases is currently unsupported",
+        );
+        check(
+            "Baz",
+            r#"
+struct Foo;
+use Foo as Bar;
+use Bar$0;
+"#,
+            "error: Renaming aliases is currently unsupported",
+        );
+    }
+
+    #[test]
+    fn test_rename_trait_method() {
+        let res = r"
+trait Foo {
+    fn foo(&self) {
+        self.foo();
+    }
+}
+
+impl Foo for () {
+    fn foo(&self) {
+        self.foo();
+    }
+}";
+        check(
+            "foo",
+            r#"
+trait Foo {
+    fn bar$0(&self) {
+        self.bar();
+    }
+}
+
+impl Foo for () {
+    fn bar(&self) {
+        self.bar();
+    }
+}"#,
+            res,
+        );
+        check(
+            "foo",
+            r#"
+trait Foo {
+    fn bar(&self) {
+        self.bar$0();
+    }
+}
+
+impl Foo for () {
+    fn bar(&self) {
+        self.bar();
+    }
+}"#,
+            res,
+        );
+        check(
+            "foo",
+            r#"
+trait Foo {
+    fn bar(&self) {
+        self.bar();
+    }
+}
+
+impl Foo for () {
+    fn bar$0(&self) {
+        self.bar();
+    }
+}"#,
+            res,
+        );
+        check(
+            "foo",
+            r#"
+trait Foo {
+    fn bar(&self) {
+        self.bar();
+    }
+}
+
+impl Foo for () {
+    fn bar(&self) {
+        self.bar$0();
+    }
+}"#,
+            res,
+        );
+    }
+
+    #[test]
+    fn test_rename_trait_const() {
+        let res = r"
+trait Foo {
+    const FOO: ();
+}
+
+impl Foo for () {
+    const FOO: ();
+}
+fn f() { <()>::FOO; }";
+        check(
+            "FOO",
+            r#"
+trait Foo {
+    const BAR$0: ();
+}
+
+impl Foo for () {
+    const BAR: ();
+}
+fn f() { <()>::BAR; }"#,
+            res,
+        );
+        check(
+            "FOO",
+            r#"
+trait Foo {
+    const BAR: ();
+}
+
+impl Foo for () {
+    const BAR$0: ();
+}
+fn f() { <()>::BAR; }"#,
+            res,
+        );
+        check(
+            "FOO",
+            r#"
+trait Foo {
+    const BAR: ();
+}
+
+impl Foo for () {
+    const BAR: ();
+}
+fn f() { <()>::BAR$0; }"#,
+            res,
+        );
+    }
+
+    #[test]
+    fn macros_are_broken_lol() {
+        cov_mark::check!(macros_are_broken_lol);
+        check(
+            "lol",
+            r#"
+macro_rules! m { () => { fn f() {} } }
+m!();
+fn main() { f$0()  }
+"#,
+            r#"
+macro_rules! m { () => { fn f() {} } }
+lol
+fn main() { lol()  }
+"#,
+        )
+    }
+}