3 files changed, 429 insertions, 89 deletions

diff --git a/crates/ide_assists/src/handlers/fill_match_arms.rs b/crates/ide_assists/src/handlers/fill_match_arms.rs
index a30c4d04e..be927cc1c 100644
--- a/crates/ide_assists/src/handlers/fill_match_arms.rs
+++ b/crates/ide_assists/src/handlers/fill_match_arms.rs
@@ -53,7 +53,7 @@ pub(crate) fn fill_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option<
         .iter()
         .filter_map(ast::MatchArm::pat)
         .flat_map(|pat| match pat {
-            // Special casee OrPat as separate top-level pats
+            // Special case OrPat as separate top-level pats
             Pat::OrPat(or_pat) => Either::Left(or_pat.pats()),
             _ => Either::Right(iter::once(pat)),
         })
@@ -72,7 +72,11 @@ pub(crate) fn fill_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option<
             .filter(|variant_pat| is_variant_missing(&top_lvl_pats, variant_pat))
             .map(|pat| make::match_arm(iter::once(pat), make::expr_empty_block()))
             .collect::<Vec<_>>();
-        if Some(enum_def) == FamousDefs(&ctx.sema, Some(module.krate())).core_option_Option() {
+        if Some(enum_def)
+            == FamousDefs(&ctx.sema, Some(module.krate()))
+                .core_option_Option()
+                .map(|x| lift_enum(x))
+        {
             // Match `Some` variant first.
             cov_mark::hit!(option_order);
             variants.reverse()
@@ -151,49 +155,99 @@ fn does_pat_match_variant(pat: &Pat, var: &Pat) -> bool {
     }
 }
 
-fn resolve_enum_def(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<hir::Enum> {
+#[derive(Eq, PartialEq, Clone)]
+enum ExtendedEnum {
+    Bool,
+    Enum(hir::Enum),
+}
+
+#[derive(Eq, PartialEq, Clone)]
+enum ExtendedVariant {
+    True,
+    False,
+    Variant(hir::Variant),
+}
+
+fn lift_enum(e: hir::Enum) -> ExtendedEnum {
+    ExtendedEnum::Enum(e)
+}
+
+impl ExtendedEnum {
+    fn variants(&self, db: &RootDatabase) -> Vec<ExtendedVariant> {
+        match self {
+            ExtendedEnum::Enum(e) => {
+                e.variants(db).into_iter().map(|x| ExtendedVariant::Variant(x)).collect::<Vec<_>>()
+            }
+            ExtendedEnum::Bool => {
+                Vec::<ExtendedVariant>::from([ExtendedVariant::True, ExtendedVariant::False])
+            }
+        }
+    }
+}
+
+fn resolve_enum_def(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<ExtendedEnum> {
     sema.type_of_expr(&expr)?.autoderef(sema.db).find_map(|ty| match ty.as_adt() {
-        Some(Adt::Enum(e)) => Some(e),
-        _ => None,
+        Some(Adt::Enum(e)) => Some(ExtendedEnum::Enum(e)),
+        _ => {
+            if ty.is_bool() {
+                Some(ExtendedEnum::Bool)
+            } else {
+                None
+            }
+        }
     })
 }
 
 fn resolve_tuple_of_enum_def(
     sema: &Semantics<RootDatabase>,
     expr: &ast::Expr,
-) -> Option<Vec<hir::Enum>> {
+) -> Option<Vec<ExtendedEnum>> {
     sema.type_of_expr(&expr)?
         .tuple_fields(sema.db)
         .iter()
         .map(|ty| {
             ty.autoderef(sema.db).find_map(|ty| match ty.as_adt() {
-                Some(Adt::Enum(e)) => Some(e),
+                Some(Adt::Enum(e)) => Some(lift_enum(e)),
                 // For now we only handle expansion for a tuple of enums. Here
                 // we map non-enum items to None and rely on `collect` to
                 // convert Vec<Option<hir::Enum>> into Option<Vec<hir::Enum>>.
-                _ => None,
+                _ => {
+                    if ty.is_bool() {
+                        Some(ExtendedEnum::Bool)
+                    } else {
+                        None
+                    }
+                }
             })
         })
         .collect()
 }
 
-fn build_pat(db: &RootDatabase, module: hir::Module, var: hir::Variant) -> Option<ast::Pat> {
-    let path = mod_path_to_ast(&module.find_use_path(db, ModuleDef::from(var))?);
+fn build_pat(db: &RootDatabase, module: hir::Module, var: ExtendedVariant) -> Option<ast::Pat> {
+    match var {
+        ExtendedVariant::Variant(var) => {
+            let path = mod_path_to_ast(&module.find_use_path(db, ModuleDef::from(var))?);
+
+            // FIXME: use HIR for this; it doesn't currently expose struct vs. tuple vs. unit variants though
+            let pat: ast::Pat = match var.source(db)?.value.kind() {
+                ast::StructKind::Tuple(field_list) => {
+                    let pats =
+                        iter::repeat(make::wildcard_pat().into()).take(field_list.fields().count());
+                    make::tuple_struct_pat(path, pats).into()
+                }
+                ast::StructKind::Record(field_list) => {
+                    let pats =
+                        field_list.fields().map(|f| make::ident_pat(f.name().unwrap()).into());
+                    make::record_pat(path, pats).into()
+                }
+                ast::StructKind::Unit => make::path_pat(path),
+            };
 
-    // FIXME: use HIR for this; it doesn't currently expose struct vs. tuple vs. unit variants though
-    let pat: ast::Pat = match var.source(db)?.value.kind() {
-        ast::StructKind::Tuple(field_list) => {
-            let pats = iter::repeat(make::wildcard_pat().into()).take(field_list.fields().count());
-            make::tuple_struct_pat(path, pats).into()
-        }
-        ast::StructKind::Record(field_list) => {
-            let pats = field_list.fields().map(|f| make::ident_pat(f.name().unwrap()).into());
-            make::record_pat(path, pats).into()
+            Some(pat)
         }
-        ast::StructKind::Unit => make::path_pat(path),
-    };
-
-    Some(pat)
+        ExtendedVariant::True => Some(ast::Pat::from(make::literal_pat("true"))),
+        ExtendedVariant::False => Some(ast::Pat::from(make::literal_pat("false"))),
+    }
 }
 
 #[cfg(test)]
@@ -226,6 +280,21 @@ mod tests {
     }
 
     #[test]
+    fn all_boolean_match_arms_provided() {
+        check_assist_not_applicable(
+            fill_match_arms,
+            r#"
+            fn foo(a: bool) {
+                match a$0 {
+                    true => {}
+                    false => {}
+                }
+            }
+            "#,
+        )
+    }
+
+    #[test]
     fn tuple_of_non_enum() {
         // for now this case is not handled, although it potentially could be
         // in the future
@@ -241,6 +310,113 @@ mod tests {
     }
 
     #[test]
+    fn fill_match_arms_boolean() {
+        check_assist(
+            fill_match_arms,
+            r#"
+            fn foo(a: bool) {
+                match a$0 {
+                }
+            }
+            "#,
+            r#"
+            fn foo(a: bool) {
+                match a {
+                    $0true => {}
+                    false => {}
+                }
+            }
+            "#,
+        )
+    }
+
+    #[test]
+    fn partial_fill_boolean() {
+        check_assist(
+            fill_match_arms,
+            r#"
+            fn foo(a: bool) {
+                match a$0 {
+                    true => {}
+                }
+            }
+            "#,
+            r#"
+            fn foo(a: bool) {
+                match a {
+                    true => {}
+                    $0false => {}
+                }
+            }
+            "#,
+        )
+    }
+
+    #[test]
+    fn all_boolean_tuple_arms_provided() {
+        check_assist_not_applicable(
+            fill_match_arms,
+            r#"
+            fn foo(a: bool) {
+                match (a, a)$0 {
+                    (true, true) => {}
+                    (true, false) => {}
+                    (false, true) => {}
+                    (false, false) => {}
+                }
+            }
+            "#,
+        )
+    }
+
+    #[test]
+    fn fill_boolean_tuple() {
+        check_assist(
+            fill_match_arms,
+            r#"
+            fn foo(a: bool) {
+                match (a, a)$0 {
+                }
+            }
+            "#,
+            r#"
+            fn foo(a: bool) {
+                match (a, a) {
+                    $0(true, true) => {}
+                    (true, false) => {}
+                    (false, true) => {}
+                    (false, false) => {}
+                }
+            }
+            "#,
+        )
+    }
+
+    #[test]
+    fn partial_fill_boolean_tuple() {
+        check_assist(
+            fill_match_arms,
+            r#"
+            fn foo(a: bool) {
+                match (a, a)$0 {
+                    (false, true) => {}
+                }
+            }
+            "#,
+            r#"
+            fn foo(a: bool) {
+                match (a, a) {
+                    (false, true) => {}
+                    $0(true, true) => {}
+                    (true, false) => {}
+                    (false, false) => {}
+                }
+            }
+            "#,
+        )
+    }
+
+    #[test]
     fn partial_fill_record_tuple() {
         check_assist(
             fill_match_arms,
diff --git a/crates/ide_assists/src/handlers/inline_local_variable.rs b/crates/ide_assists/src/handlers/inline_local_variable.rs
index ea1466dc8..f5dafc8cb 100644
--- a/crates/ide_assists/src/handlers/inline_local_variable.rs
+++ b/crates/ide_assists/src/handlers/inline_local_variable.rs
@@ -1,7 +1,9 @@
-use ide_db::{defs::Definition, search::FileReference};
+use either::Either;
+use hir::PathResolution;
+use ide_db::{base_db::FileId, defs::Definition, search::FileReference};
 use rustc_hash::FxHashMap;
 use syntax::{
-    ast::{self, AstNode, AstToken},
+    ast::{self, AstNode, AstToken, NameOwner},
     TextRange,
 };
 
@@ -27,44 +29,28 @@ use crate::{
 // }
 // ```
 pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let let_stmt = ctx.find_node_at_offset::<ast::LetStmt>()?;
-    let bind_pat = match let_stmt.pat()? {
-        ast::Pat::IdentPat(pat) => pat,
-        _ => return None,
-    };
-    if bind_pat.mut_token().is_some() {
-        cov_mark::hit!(test_not_inline_mut_variable);
-        return None;
-    }
-    if !bind_pat.syntax().text_range().contains_inclusive(ctx.offset()) {
-        cov_mark::hit!(not_applicable_outside_of_bind_pat);
-        return None;
-    }
+    let InlineData { let_stmt, delete_let, replace_usages, target } =
+        inline_let(ctx).or_else(|| inline_usage(ctx))?;
     let initializer_expr = let_stmt.initializer()?;
 
-    let def = ctx.sema.to_def(&bind_pat)?;
-    let def = Definition::Local(def);
-    let usages = def.usages(&ctx.sema).all();
-    if usages.is_empty() {
-        cov_mark::hit!(test_not_applicable_if_variable_unused);
-        return None;
-    };
-
-    let delete_range = if let Some(whitespace) = let_stmt
-        .syntax()
-        .next_sibling_or_token()
-        .and_then(|it| ast::Whitespace::cast(it.as_token()?.clone()))
-    {
-        TextRange::new(
-            let_stmt.syntax().text_range().start(),
-            whitespace.syntax().text_range().end(),
-        )
+    let delete_range = if delete_let {
+        if let Some(whitespace) = let_stmt
+            .syntax()
+            .next_sibling_or_token()
+            .and_then(|it| ast::Whitespace::cast(it.as_token()?.clone()))
+        {
+            Some(TextRange::new(
+                let_stmt.syntax().text_range().start(),
+                whitespace.syntax().text_range().end(),
+            ))
+        } else {
+            Some(let_stmt.syntax().text_range())
+        }
     } else {
-        let_stmt.syntax().text_range()
+        None
     };
 
-    let wrap_in_parens = usages
-        .references
+    let wrap_in_parens = replace_usages
         .iter()
         .map(|(&file_id, refs)| {
             refs.iter()
@@ -114,14 +100,20 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
     let init_str = initializer_expr.syntax().text().to_string();
     let init_in_paren = format!("({})", &init_str);
 
-    let target = bind_pat.syntax().text_range();
+    let target = match target {
+        ast::NameOrNameRef::Name(it) => it.syntax().text_range(),
+        ast::NameOrNameRef::NameRef(it) => it.syntax().text_range(),
+    };
+
     acc.add(
         AssistId("inline_local_variable", AssistKind::RefactorInline),
         "Inline variable",
         target,
         move |builder| {
-            builder.delete(delete_range);
-            for (file_id, references) in usages.references {
+            if let Some(range) = delete_range {
+                builder.delete(range);
+            }
+            for (file_id, references) in replace_usages {
                 for (&should_wrap, reference) in wrap_in_parens[&file_id].iter().zip(references) {
                     let replacement =
                         if should_wrap { init_in_paren.clone() } else { init_str.clone() };
@@ -140,6 +132,81 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
     )
 }
 
+struct InlineData {
+    let_stmt: ast::LetStmt,
+    delete_let: bool,
+    target: ast::NameOrNameRef,
+    replace_usages: FxHashMap<FileId, Vec<FileReference>>,
+}
+
+fn inline_let(ctx: &AssistContext) -> Option<InlineData> {
+    let let_stmt = ctx.find_node_at_offset::<ast::LetStmt>()?;
+    let bind_pat = match let_stmt.pat()? {
+        ast::Pat::IdentPat(pat) => pat,
+        _ => return None,
+    };
+    if bind_pat.mut_token().is_some() {
+        cov_mark::hit!(test_not_inline_mut_variable);
+        return None;
+    }
+    if !bind_pat.syntax().text_range().contains_inclusive(ctx.offset()) {
+        cov_mark::hit!(not_applicable_outside_of_bind_pat);
+        return None;
+    }
+
+    let def = ctx.sema.to_def(&bind_pat)?;
+    let def = Definition::Local(def);
+    let usages = def.usages(&ctx.sema).all();
+    if usages.is_empty() {
+        cov_mark::hit!(test_not_applicable_if_variable_unused);
+        return None;
+    };
+
+    Some(InlineData {
+        let_stmt,
+        delete_let: true,
+        target: ast::NameOrNameRef::Name(bind_pat.name()?),
+        replace_usages: usages.references,
+    })
+}
+
+fn inline_usage(ctx: &AssistContext) -> Option<InlineData> {
+    let path_expr = ctx.find_node_at_offset::<ast::PathExpr>()?;
+    let path = path_expr.path()?;
+    let name = match path.as_single_segment()?.kind()? {
+        ast::PathSegmentKind::Name(name) => name,
+        _ => return None,
+    };
+
+    let local = match ctx.sema.resolve_path(&path)? {
+        PathResolution::Local(local) => local,
+        _ => return None,
+    };
+
+    let bind_pat = match local.source(ctx.db()).value {
+        Either::Left(ident) => ident,
+        _ => return None,
+    };
+
+    let let_stmt = ast::LetStmt::cast(bind_pat.syntax().parent()?)?;
+
+    let def = Definition::Local(local);
+    let mut usages = def.usages(&ctx.sema).all();
+
+    let delete_let = usages.references.values().map(|v| v.len()).sum::<usize>() == 1;
+
+    for references in usages.references.values_mut() {
+        references.retain(|reference| reference.name.as_name_ref() == Some(&name));
+    }
+
+    Some(InlineData {
+        let_stmt,
+        delete_let,
+        target: ast::NameOrNameRef::NameRef(name),
+        replace_usages: usages.references,
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use crate::tests::{check_assist, check_assist_not_applicable};
@@ -726,4 +793,84 @@ fn main() {
 ",
         )
     }
+
+    #[test]
+    fn works_on_local_usage() {
+        check_assist(
+            inline_local_variable,
+            r#"
+fn f() {
+    let xyz = 0;
+    xyz$0;
+}
+"#,
+            r#"
+fn f() {
+    0;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn does_not_remove_let_when_multiple_usages() {
+        check_assist(
+            inline_local_variable,
+            r#"
+fn f() {
+    let xyz = 0;
+    xyz$0;
+    xyz;
+}
+"#,
+            r#"
+fn f() {
+    let xyz = 0;
+    0;
+    xyz;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn not_applicable_with_non_ident_pattern() {
+        check_assist_not_applicable(
+            inline_local_variable,
+            r#"
+fn main() {
+    let (x, y) = (0, 1);
+    x$0;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn not_applicable_on_local_usage_in_macro() {
+        check_assist_not_applicable(
+            inline_local_variable,
+            r#"
+macro_rules! m {
+    ($i:ident) => { $i }
+}
+fn f() {
+    let xyz = 0;
+    m!(xyz$0); // replacing it would break the macro
+}
+"#,
+        );
+        check_assist_not_applicable(
+            inline_local_variable,
+            r#"
+macro_rules! m {
+    ($i:ident) => { $i }
+}
+fn f() {
+    let xyz$0 = 0;
+    m!(xyz); // replacing it would break the macro
+}
+"#,
+        );
+    }
 }
diff --git a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
index 870a8d4ff..694d897d1 100644
--- a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
+++ b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
@@ -47,6 +47,11 @@ pub(crate) fn replace_derive_with_manual_impl(
         return None;
     }
 
+    if !args.syntax().text_range().contains(ctx.offset()) {
+        cov_mark::hit!(outside_of_attr_args);
+        return None;
+    }
+
     let trait_token = args.syntax().token_at_offset(ctx.offset()).find(|t| t.kind() == IDENT)?;
     let trait_name = trait_token.text();
 
@@ -207,7 +212,7 @@ mod tests {
     fn add_custom_impl_debug() {
         check_assist(
             replace_derive_with_manual_impl,
-            "
+            r#"
 mod fmt {
     pub struct Error;
     pub type Result = Result<(), Error>;
@@ -221,8 +226,8 @@ mod fmt {
 struct Foo {
     bar: String,
 }
-",
-            "
+"#,
+            r#"
 mod fmt {
     pub struct Error;
     pub type Result = Result<(), Error>;
@@ -241,14 +246,14 @@ impl fmt::Debug for Foo {
         ${0:todo!()}
     }
 }
-",
+"#,
         )
     }
     #[test]
     fn add_custom_impl_all() {
         check_assist(
             replace_derive_with_manual_impl,
-            "
+            r#"
 mod foo {
     pub trait Bar {
         type Qux;
@@ -263,8 +268,8 @@ mod foo {
 struct Foo {
     bar: String,
 }
-",
-            "
+"#,
+            r#"
 mod foo {
     pub trait Bar {
         type Qux;
@@ -290,20 +295,20 @@ impl foo::Bar for Foo {
         todo!()
     }
 }
-",
+"#,
         )
     }
     #[test]
     fn add_custom_impl_for_unique_input() {
         check_assist(
             replace_derive_with_manual_impl,
-            "
+            r#"
 #[derive(Debu$0g)]
 struct Foo {
     bar: String,
 }
-            ",
-            "
+            "#,
+            r#"
 struct Foo {
     bar: String,
 }
@@ -311,7 +316,7 @@ struct Foo {
 impl Debug for Foo {
     $0
 }
-            ",
+            "#,
         )
     }
 
@@ -319,13 +324,13 @@ impl Debug for Foo {
     fn add_custom_impl_for_with_visibility_modifier() {
         check_assist(
             replace_derive_with_manual_impl,
-            "
+            r#"
 #[derive(Debug$0)]
 pub struct Foo {
     bar: String,
 }
-            ",
-            "
+            "#,
+            r#"
 pub struct Foo {
     bar: String,
 }
@@ -333,7 +338,7 @@ pub struct Foo {
 impl Debug for Foo {
     $0
 }
-            ",
+            "#,
         )
     }
 
@@ -341,18 +346,18 @@ impl Debug for Foo {
     fn add_custom_impl_when_multiple_inputs() {
         check_assist(
             replace_derive_with_manual_impl,
-            "
+            r#"
 #[derive(Display, Debug$0, Serialize)]
 struct Foo {}
-            ",
-            "
+            "#,
+            r#"
 #[derive(Display, Serialize)]
 struct Foo {}
 
 impl Debug for Foo {
     $0
 }
-            ",
+            "#,
         )
     }
 
@@ -360,10 +365,10 @@ impl Debug for Foo {
     fn test_ignore_derive_macro_without_input() {
         check_assist_not_applicable(
             replace_derive_with_manual_impl,
-            "
+            r#"
 #[derive($0)]
 struct Foo {}
-            ",
+            "#,
         )
     }
 
@@ -371,18 +376,18 @@ struct Foo {}
     fn test_ignore_if_cursor_on_param() {
         check_assist_not_applicable(
             replace_derive_with_manual_impl,
-            "
+            r#"
 #[derive$0(Debug)]
 struct Foo {}
-            ",
+            "#,
         );
 
         check_assist_not_applicable(
             replace_derive_with_manual_impl,
-            "
+            r#"
 #[derive(Debug)$0]
 struct Foo {}
-            ",
+            "#,
         )
     }
 
@@ -390,10 +395,22 @@ struct Foo {}
     fn test_ignore_if_not_derive() {
         check_assist_not_applicable(
             replace_derive_with_manual_impl,
-            "
+            r#"
 #[allow(non_camel_$0case_types)]
 struct Foo {}
-            ",
+            "#,
         )
     }
+
+    #[test]
+    fn works_at_start_of_file() {
+        cov_mark::check!(outside_of_attr_args);
+        check_assist_not_applicable(
+            replace_derive_with_manual_impl,
+            r#"
+$0#[derive(Debug)]
+struct S;
+            "#,
+        );
+    }
 }