9 files changed, 287 insertions, 192 deletions

diff --git a/crates/ide_assists/src/handlers/apply_demorgan.rs b/crates/ide_assists/src/handlers/apply_demorgan.rs
index c93959e66..e2bd6e456 100644
--- a/crates/ide_assists/src/handlers/apply_demorgan.rs
+++ b/crates/ide_assists/src/handlers/apply_demorgan.rs
@@ -147,74 +147,92 @@ fn opposite_logic_op(kind: ast::BinOp) -> Option<&'static str> {
 
 #[cfg(test)]
 mod tests {
-    use ide_db::helpers::FamousDefs;
-
-    use super::*;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
-    const ORDABLE_FIXTURE: &'static str = r"
-//- /lib.rs deps:core crate:ordable
-struct NonOrderable;
-struct Orderable;
-impl core::cmp::Ord for Orderable {}
-";
-
-    fn check(ra_fixture_before: &str, ra_fixture_after: &str) {
-        let before = &format!(
-            "//- /main.rs crate:main deps:core,ordable\n{}\n{}{}",
-            ra_fixture_before,
-            FamousDefs::FIXTURE,
-            ORDABLE_FIXTURE
-        );
-        check_assist(apply_demorgan, before, &format!("{}\n", ra_fixture_after));
-    }
+    use super::*;
 
     #[test]
     fn demorgan_handles_leq() {
-        check(
-            r"use ordable::Orderable;
+        check_assist(
+            apply_demorgan,
+            r#"
+//- minicore: ord, derive
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+struct S;
+
 fn f() {
-    Orderable < Orderable &&$0 Orderable <= Orderable
-}",
-            r"use ordable::Orderable;
+    S < S &&$0 S <= S
+}
+"#,
+            r#"
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+struct S;
+
 fn f() {
-    !(Orderable >= Orderable || Orderable > Orderable)
-}",
+    !(S >= S || S > S)
+}
+"#,
         );
-        check(
-            r"use ordable::NonOrderable;
+
+        check_assist(
+            apply_demorgan,
+            r#"
+//- minicore: ord, derive
+struct S;
+
 fn f() {
-    NonOrderable < NonOrderable &&$0 NonOrderable <= NonOrderable
-}",
-            r"use ordable::NonOrderable;
+    S < S &&$0 S <= S
+}
+"#,
+            r#"
+struct S;
+
 fn f() {
-    !(!(NonOrderable < NonOrderable) || !(NonOrderable <= NonOrderable))
-}",
+    !(!(S < S) || !(S <= S))
+}
+"#,
         );
     }
 
     #[test]
     fn demorgan_handles_geq() {
-        check(
-            r"use ordable::Orderable;
+        check_assist(
+            apply_demorgan,
+            r#"
+//- minicore: ord, derive
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+struct S;
+
 fn f() {
-    Orderable > Orderable &&$0 Orderable >= Orderable
-}",
-            r"use ordable::Orderable;
+    S > S &&$0 S >= S
+}
+"#,
+            r#"
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+struct S;
+
 fn f() {
-    !(Orderable <= Orderable || Orderable < Orderable)
-}",
+    !(S <= S || S < S)
+}
+"#,
         );
-        check(
-            r"use ordable::NonOrderable;
+        check_assist(
+            apply_demorgan,
+            r#"
+//- minicore: ord, derive
+struct S;
+
 fn f() {
-    Orderable > Orderable &&$0 Orderable >= Orderable
-}",
-            r"use ordable::NonOrderable;
+    S > S &&$0 S >= S
+}
+"#,
+            r#"
+struct S;
+
 fn f() {
-    !(!(Orderable > Orderable) || !(Orderable >= Orderable))
-}",
+    !(!(S > S) || !(S >= S))
+}
+"#,
         );
     }
 
diff --git a/crates/ide_assists/src/handlers/convert_into_to_from.rs b/crates/ide_assists/src/handlers/convert_into_to_from.rs
index 199e1ad5c..79a0c4879 100644
--- a/crates/ide_assists/src/handlers/convert_into_to_from.rs
+++ b/crates/ide_assists/src/handlers/convert_into_to_from.rs
@@ -6,6 +6,8 @@ use syntax::ast::{self, AstNode, NameOwner};
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
+// FIXME: this should be a diagnostic
+
 // Assist: convert_into_to_from
 //
 // Converts an Into impl to an equivalent From impl.
@@ -114,12 +116,14 @@ pub(crate) fn convert_into_to_from(acc: &mut Assists, ctx: &AssistContext) -> Op
 mod tests {
     use super::*;
 
-    use crate::tests::check_assist;
+    use crate::tests::{check_assist, check_assist_not_applicable};
 
     #[test]
     fn convert_into_to_from_converts_a_struct() {
-        check_convert_into_to_from(
+        check_assist(
+            convert_into_to_from,
             r#"
+//- minicore: from
 struct Thing {
     a: String,
     b: usize
@@ -154,8 +158,10 @@ impl From<usize> for Thing {
 
     #[test]
     fn convert_into_to_from_converts_enums() {
-        check_convert_into_to_from(
+        check_assist(
+            convert_into_to_from,
             r#"
+//- minicore: from
 enum Thing {
     Foo(String),
     Bar(String)
@@ -190,8 +196,10 @@ impl From<Thing> for String {
 
     #[test]
     fn convert_into_to_from_on_enum_with_lifetimes() {
-        check_convert_into_to_from(
+        check_assist(
+            convert_into_to_from,
             r#"
+//- minicore: from
 enum Thing<'a> {
     Foo(&'a str),
     Bar(&'a str)
@@ -226,8 +234,10 @@ impl<'a> From<Thing<'a>> for &'a str {
 
     #[test]
     fn convert_into_to_from_works_on_references() {
-        check_convert_into_to_from(
+        check_assist(
+            convert_into_to_from,
             r#"
+//- minicore: from
 struct Thing(String);
 
 impl $0core::convert::Into<String> for &Thing {
@@ -250,8 +260,10 @@ impl From<&Thing> for String {
 
     #[test]
     fn convert_into_to_from_works_on_qualified_structs() {
-        check_convert_into_to_from(
+        check_assist(
+            convert_into_to_from,
             r#"
+//- minicore: from
 mod things {
     pub struct Thing(String);
     pub struct BetterThing(String);
@@ -280,8 +292,10 @@ impl From<&things::Thing> for things::BetterThing {
 
     #[test]
     fn convert_into_to_from_works_on_qualified_enums() {
-        check_convert_into_to_from(
+        check_assist(
+            convert_into_to_from,
             r#"
+//- minicore: from
 mod things {
     pub enum Thing {
         A(String)
@@ -323,10 +337,12 @@ impl From<&things::Thing> for things::BetterThing {
     #[test]
     fn convert_into_to_from_not_applicable_on_any_trait_named_into() {
         check_assist_not_applicable(
+            convert_into_to_from,
             r#"
-pub trait Into<T> {{
+//- minicore: from
+pub trait Into<T> {
     pub fn into(self) -> T;
-}}
+}
 
 struct Thing {
     a: String,
@@ -342,14 +358,4 @@ impl $0Into<Thing> for String {
 "#,
         );
     }
-
-    fn check_convert_into_to_from(before: &str, after: &str) {
-        let before = &format!("//- /main.rs crate:main deps:core{}{}", before, FamousDefs::FIXTURE);
-        check_assist(convert_into_to_from, before, after);
-    }
-
-    fn check_assist_not_applicable(before: &str) {
-        let before = &format!("//- /main.rs crate:main deps:core{}{}", before, FamousDefs::FIXTURE);
-        crate::tests::check_assist_not_applicable(convert_into_to_from, before);
-    }
 }
diff --git a/crates/ide_assists/src/handlers/extract_function.rs b/crates/ide_assists/src/handlers/extract_function.rs
index f2be091f4..7085a0c48 100644
--- a/crates/ide_assists/src/handlers/extract_function.rs
+++ b/crates/ide_assists/src/handlers/extract_function.rs
@@ -1384,7 +1384,7 @@ fn fix_param_usages(ctx: &AssistContext, params: &[Param], syntax: &SyntaxNode)
     for (param, usages) in usages_for_param {
         for usage in usages {
             match usage.syntax().ancestors().skip(1).find_map(ast::Expr::cast) {
-                Some(ast::Expr::MethodCallExpr(_)) | Some(ast::Expr::FieldExpr(_)) => {
+                Some(ast::Expr::MethodCallExpr(_) | ast::Expr::FieldExpr(_)) => {
                     // do nothing
                 }
                 Some(ast::Expr::RefExpr(node))
diff --git a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
index d3ff7b65c..6c6ff16c2 100644
--- a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -48,6 +48,7 @@ pub(crate) fn extract_struct_from_enum_variant(
     let variant_name = variant.name()?;
     let variant_hir = ctx.sema.to_def(&variant)?;
     if existing_definition(ctx.db(), &variant_name, &variant_hir) {
+        cov_mark::hit!(test_extract_enum_not_applicable_if_struct_exists);
         return None;
     }
 
@@ -300,18 +301,10 @@ fn reference_to_node(
 
 #[cfg(test)]
 mod tests {
-    use ide_db::helpers::FamousDefs;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
 
-    fn check_not_applicable(ra_fixture: &str) {
-        let fixture =
-            format!("//- /main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
-        check_assist_not_applicable(extract_struct_from_enum_variant, &fixture)
-    }
-
     #[test]
     fn test_extract_struct_several_fields_tuple() {
         check_assist(
@@ -699,29 +692,33 @@ fn foo() {
 
     #[test]
     fn test_extract_enum_not_applicable_for_element_with_no_fields() {
-        check_not_applicable("enum A { $0One }");
+        check_assist_not_applicable(extract_struct_from_enum_variant, r#"enum A { $0One }"#);
     }
 
     #[test]
     fn test_extract_enum_not_applicable_if_struct_exists() {
-        check_not_applicable(
-            r#"struct One;
-        enum A { $0One(u8, u32) }"#,
+        cov_mark::check!(test_extract_enum_not_applicable_if_struct_exists);
+        check_assist_not_applicable(
+            extract_struct_from_enum_variant,
+            r#"
+struct One;
+enum A { $0One(u8, u32) }
+"#,
         );
     }
 
     #[test]
     fn test_extract_not_applicable_one_field() {
-        check_not_applicable(r"enum A { $0One(u32) }");
+        check_assist_not_applicable(extract_struct_from_enum_variant, r"enum A { $0One(u32) }");
     }
 
     #[test]
     fn test_extract_not_applicable_no_field_tuple() {
-        check_not_applicable(r"enum A { $0None() }");
+        check_assist_not_applicable(extract_struct_from_enum_variant, r"enum A { $0None() }");
     }
 
     #[test]
     fn test_extract_not_applicable_no_field_named() {
-        check_not_applicable(r"enum A { $0None {} }");
+        check_assist_not_applicable(extract_struct_from_enum_variant, r"enum A { $0None {} }");
     }
 }
diff --git a/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs b/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs
index 588ee1350..e55c38502 100644
--- a/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs
+++ b/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs
@@ -1,5 +1,4 @@
-use ide_db::helpers::FamousDefs;
-use ide_db::RootDatabase;
+use ide_db::{helpers::FamousDefs, RootDatabase};
 use syntax::ast::{self, AstNode, NameOwner};
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
@@ -92,23 +91,20 @@ mod tests {
 
     use super::*;
 
-    fn check_not_applicable(ra_fixture: &str) {
-        let fixture =
-            format!("//- /main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
-        check_assist_not_applicable(generate_default_from_enum_variant, &fixture)
-    }
-
     #[test]
     fn test_generate_default_from_variant() {
         check_assist(
             generate_default_from_enum_variant,
             r#"
+//- minicore: default
 enum Variant {
     Undefined,
     Minor$0,
     Major,
-}"#,
-            r#"enum Variant {
+}
+"#,
+            r#"
+enum Variant {
     Undefined,
     Minor,
     Major,
@@ -118,15 +114,18 @@ impl Default for Variant {
     fn default() -> Self {
         Self::Minor
     }
-}"#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_generate_default_already_implemented() {
         cov_mark::check!(test_gen_default_impl_already_exists);
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_default_from_enum_variant,
             r#"
+//- minicore: default
 enum Variant {
     Undefined,
     Minor$0,
@@ -137,20 +136,24 @@ impl Default for Variant {
     fn default() -> Self {
         Self::Minor
     }
-}"#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_add_from_impl_no_element() {
         cov_mark::check!(test_gen_default_on_non_unit_variant_not_implemented);
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_default_from_enum_variant,
             r#"
+//- minicore: default
 enum Variant {
     Undefined,
     Minor(u32)$0,
     Major,
-}"#,
+}
+"#,
         );
     }
 
@@ -158,7 +161,10 @@ enum Variant {
     fn test_generate_default_from_variant_with_one_variant() {
         check_assist(
             generate_default_from_enum_variant,
-            r#"enum Variant { Undefi$0ned }"#,
+            r#"
+//- minicore: default
+enum Variant { Undefi$0ned }
+"#,
             r#"
 enum Variant { Undefined }
 
@@ -166,7 +172,8 @@ impl Default for Variant {
     fn default() -> Self {
         Self::Undefined
     }
-}"#,
+}
+"#,
         );
     }
 }
diff --git a/crates/ide_assists/src/handlers/generate_default_from_new.rs b/crates/ide_assists/src/handlers/generate_default_from_new.rs
index bad826366..b54ec59da 100644
--- a/crates/ide_assists/src/handlers/generate_default_from_new.rs
+++ b/crates/ide_assists/src/handlers/generate_default_from_new.rs
@@ -1,7 +1,3 @@
-use crate::{
-    assist_context::{AssistContext, Assists},
-    AssistId,
-};
 use ide_db::helpers::FamousDefs;
 use itertools::Itertools;
 use stdx::format_to;
@@ -10,6 +6,11 @@ use syntax::{
     AstNode,
 };
 
+use crate::{
+    assist_context::{AssistContext, Assists},
+    AssistId,
+};
+
 // Assist: generate_default_from_new
 //
 // Generates default implementation from new method.
@@ -140,16 +141,16 @@ fn is_default_implemented(ctx: &AssistContext, impl_: &Impl) -> bool {
 
 #[cfg(test)]
 mod tests {
-    use ide_db::helpers::FamousDefs;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
 
     #[test]
     fn generate_default() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 struct Example { _inner: () }
 
 impl Example {
@@ -182,8 +183,10 @@ fn main() {}
 
     #[test]
     fn generate_default2() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 struct Test { value: u32 }
 
 impl Test {
@@ -212,8 +215,10 @@ impl Default for Test {
 
     #[test]
     fn new_function_with_generic() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 pub struct Foo<T> {
     _bar: *mut T,
 }
@@ -246,8 +251,10 @@ impl<T> Default for Foo<T> {
 
     #[test]
     fn new_function_with_generics() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 pub struct Foo<T, B> {
     _tars: *mut T,
     _bar: *mut B,
@@ -282,8 +289,10 @@ impl<T, B> Default for Foo<T, B> {
 
     #[test]
     fn new_function_with_generic_and_bound() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 pub struct Foo<T> {
     t: T,
 }
@@ -316,8 +325,10 @@ impl<T: From<i32>> Default for Foo<T> {
 
     #[test]
     fn new_function_with_generics_and_bounds() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 pub struct Foo<T, B> {
     _tars: T,
     _bar: B,
@@ -352,8 +363,10 @@ impl<T: From<i32>, B: From<i64>> Default for Foo<T, B> {
 
     #[test]
     fn new_function_with_generic_and_where() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 pub struct Foo<T> {
     t: T,
 }
@@ -395,8 +408,10 @@ where
 
     #[test]
     fn new_function_with_generics_and_wheres() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 pub struct Foo<T, B> {
     _tars: T,
     _bar: B,
@@ -441,8 +456,10 @@ where
     #[test]
     fn new_function_with_parameters() {
         cov_mark::check!(new_function_with_parameters);
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_default_from_new,
             r#"
+//- minicore: default
 struct Example { _inner: () }
 
 impl Example {
@@ -457,7 +474,8 @@ impl Example {
     #[test]
     fn other_function_than_new() {
         cov_mark::check!(other_function_than_new);
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_default_from_new,
             r#"
 struct Example { _inner: () }
 
@@ -474,8 +492,10 @@ impl Example {
     #[test]
     fn default_block_is_already_present() {
         cov_mark::check!(default_block_is_already_present);
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_default_from_new,
             r#"
+//- minicore: default
 struct Example { _inner: () }
 
 impl Example {
@@ -495,7 +515,8 @@ impl Default for Example {
 
     #[test]
     fn standalone_new_function() {
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_default_from_new,
             r#"
 fn n$0ew() -> u32 {
     0
@@ -506,8 +527,10 @@ fn n$0ew() -> u32 {
 
     #[test]
     fn multiple_struct_blocks() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 struct Example { _inner: () }
 struct Test { value: u32 }
 
@@ -538,8 +561,10 @@ impl Default for Example {
 
     #[test]
     fn when_struct_is_after_impl() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 impl Example {
     pub fn $0new() -> Self {
         Self { _inner: () }
@@ -568,8 +593,10 @@ struct Example { _inner: () }
 
     #[test]
     fn struct_in_module() {
-        check_pass(
+        check_assist(
+            generate_default_from_new,
             r#"
+//- minicore: default
 mod test {
     struct Example { _inner: () }
 
@@ -603,8 +630,10 @@ impl Default for Example {
     #[test]
     fn struct_in_module_with_default() {
         cov_mark::check!(struct_in_module_with_default);
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_default_from_new,
             r#"
+//- minicore: default
 mod test {
     struct Example { _inner: () }
 
@@ -623,14 +652,4 @@ mod test {
 "#,
         );
     }
-
-    fn check_pass(before: &str, after: &str) {
-        let before = &format!("//- /main.rs crate:main deps:core{}{}", before, FamousDefs::FIXTURE);
-        check_assist(generate_default_from_new, before, after);
-    }
-
-    fn check_not_applicable(before: &str) {
-        let before = &format!("//- /main.rs crate:main deps:core{}{}", before, FamousDefs::FIXTURE);
-        check_assist_not_applicable(generate_default_from_new, before);
-    }
 }
diff --git a/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs b/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs
index ce6998d82..8727be07d 100644
--- a/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs
+++ b/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs
@@ -110,14 +110,19 @@ mod tests {
     fn test_generate_from_impl_for_enum() {
         check_assist(
             generate_from_impl_for_enum,
-            "enum A { $0One(u32) }",
-            r#"enum A { One(u32) }
+            r#"
+//- minicore: from
+enum A { $0One(u32) }
+"#,
+            r#"
+enum A { One(u32) }
 
 impl From<u32> for A {
     fn from(v: u32) -> Self {
         Self::One(v)
     }
-}"#,
+}
+"#,
         );
     }
 
@@ -125,53 +130,71 @@ impl From<u32> for A {
     fn test_generate_from_impl_for_enum_complicated_path() {
         check_assist(
             generate_from_impl_for_enum,
-            r#"enum A { $0One(foo::bar::baz::Boo) }"#,
-            r#"enum A { One(foo::bar::baz::Boo) }
+            r#"
+//- minicore: from
+enum A { $0One(foo::bar::baz::Boo) }
+"#,
+            r#"
+enum A { One(foo::bar::baz::Boo) }
 
 impl From<foo::bar::baz::Boo> for A {
     fn from(v: foo::bar::baz::Boo) -> Self {
         Self::One(v)
     }
-}"#,
+}
+"#,
         );
     }
 
-    fn check_not_applicable(ra_fixture: &str) {
-        let fixture =
-            format!("//- /main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
-        check_assist_not_applicable(generate_from_impl_for_enum, &fixture)
-    }
-
     #[test]
     fn test_add_from_impl_no_element() {
-        check_not_applicable("enum A { $0One }");
+        check_assist_not_applicable(
+            generate_from_impl_for_enum,
+            r#"
+//- minicore: from
+enum A { $0One }
+"#,
+        );
     }
 
     #[test]
     fn test_add_from_impl_more_than_one_element_in_tuple() {
-        check_not_applicable("enum A { $0One(u32, String) }");
+        check_assist_not_applicable(
+            generate_from_impl_for_enum,
+            r#"
+//- minicore: from
+enum A { $0One(u32, String) }
+"#,
+        );
     }
 
     #[test]
     fn test_add_from_impl_struct_variant() {
         check_assist(
             generate_from_impl_for_enum,
-            "enum A { $0One { x: u32 } }",
-            r#"enum A { One { x: u32 } }
+            r#"
+//- minicore: from
+enum A { $0One { x: u32 } }
+"#,
+            r#"
+enum A { One { x: u32 } }
 
 impl From<u32> for A {
     fn from(x: u32) -> Self {
         Self::One { x }
     }
-}"#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_add_from_impl_already_exists() {
         cov_mark::check!(test_add_from_impl_already_exists);
-        check_not_applicable(
+        check_assist_not_applicable(
+            generate_from_impl_for_enum,
             r#"
+//- minicore: from
 enum A { $0One(u32), }
 
 impl From<u32> for A {
@@ -187,7 +210,9 @@ impl From<u32> for A {
     fn test_add_from_impl_different_variant_impl_exists() {
         check_assist(
             generate_from_impl_for_enum,
-            r#"enum A { $0One(u32), Two(String), }
+            r#"
+//- minicore: from
+enum A { $0One(u32), Two(String), }
 
 impl From<String> for A {
     fn from(v: String) -> Self {
@@ -197,8 +222,10 @@ impl From<String> for A {
 
 pub trait From<T> {
     fn from(T) -> Self;
-}"#,
-            r#"enum A { One(u32), Two(String), }
+}
+"#,
+            r#"
+enum A { One(u32), Two(String), }
 
 impl From<u32> for A {
     fn from(v: u32) -> Self {
@@ -214,7 +241,8 @@ impl From<String> for A {
 
 pub trait From<T> {
     fn from(T) -> Self;
-}"#,
+}
+"#,
         );
     }
 
@@ -222,14 +250,19 @@ pub trait From<T> {
     fn test_add_from_impl_static_str() {
         check_assist(
             generate_from_impl_for_enum,
-            "enum A { $0One(&'static str) }",
-            r#"enum A { One(&'static str) }
+            r#"
+//- minicore: from
+enum A { $0One(&'static str) }
+"#,
+            r#"
+enum A { One(&'static str) }
 
 impl From<&'static str> for A {
     fn from(v: &'static str) -> Self {
         Self::One(v)
     }
-}"#,
+}
+"#,
         );
     }
 
@@ -237,14 +270,19 @@ impl From<&'static str> for A {
     fn test_add_from_impl_generic_enum() {
         check_assist(
             generate_from_impl_for_enum,
-            "enum Generic<T, U: Clone> { $0One(T), Two(U) }",
-            r#"enum Generic<T, U: Clone> { One(T), Two(U) }
+            r#"
+//- minicore: from
+enum Generic<T, U: Clone> { $0One(T), Two(U) }
+"#,
+            r#"
+enum Generic<T, U: Clone> { One(T), Two(U) }
 
 impl<T, U: Clone> From<T> for Generic<T, U> {
     fn from(v: T) -> Self {
         Self::One(v)
     }
-}"#,
+}
+"#,
         );
     }
 
@@ -252,14 +290,19 @@ impl<T, U: Clone> From<T> for Generic<T, U> {
     fn test_add_from_impl_with_lifetime() {
         check_assist(
             generate_from_impl_for_enum,
-            "enum Generic<'a> { $0One(&'a i32) }",
-            r#"enum Generic<'a> { One(&'a i32) }
+            r#"
+//- minicore: from
+enum Generic<'a> { $0One(&'a i32) }
+"#,
+            r#"
+enum Generic<'a> { One(&'a i32) }
 
 impl<'a> From<&'a i32> for Generic<'a> {
     fn from(v: &'a i32) -> Self {
         Self::One(v)
     }
-}"#,
+}
+"#,
         );
     }
 }
diff --git a/crates/ide_assists/src/handlers/inline_local_variable.rs b/crates/ide_assists/src/handlers/inline_local_variable.rs
index 2441dbb8b..945d28650 100644
--- a/crates/ide_assists/src/handlers/inline_local_variable.rs
+++ b/crates/ide_assists/src/handlers/inline_local_variable.rs
@@ -65,32 +65,35 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
                         Some(u) => u,
                         None => return Some(false),
                     };
-
-                    Some(!matches!(
-                        (&initializer_expr, usage_parent),
-                        (ast::Expr::CallExpr(_), _)
-                            | (ast::Expr::IndexExpr(_), _)
-                            | (ast::Expr::MethodCallExpr(_), _)
-                            | (ast::Expr::FieldExpr(_), _)
-                            | (ast::Expr::TryExpr(_), _)
-                            | (ast::Expr::RefExpr(_), _)
-                            | (ast::Expr::Literal(_), _)
-                            | (ast::Expr::TupleExpr(_), _)
-                            | (ast::Expr::ArrayExpr(_), _)
-                            | (ast::Expr::ParenExpr(_), _)
-                            | (ast::Expr::PathExpr(_), _)
-                            | (ast::Expr::BlockExpr(_), _)
-                            | (ast::Expr::EffectExpr(_), _)
-                            | (_, ast::Expr::CallExpr(_))
-                            | (_, ast::Expr::TupleExpr(_))
-                            | (_, ast::Expr::ArrayExpr(_))
-                            | (_, ast::Expr::ParenExpr(_))
-                            | (_, ast::Expr::ForExpr(_))
-                            | (_, ast::Expr::WhileExpr(_))
-                            | (_, ast::Expr::BreakExpr(_))
-                            | (_, ast::Expr::ReturnExpr(_))
-                            | (_, ast::Expr::MatchExpr(_))
-                    ))
+                    Some(
+                        !(matches!(
+                            initializer_expr,
+                            ast::Expr::CallExpr(_)
+                                | ast::Expr::IndexExpr(_)
+                                | ast::Expr::MethodCallExpr(_)
+                                | ast::Expr::FieldExpr(_)
+                                | ast::Expr::TryExpr(_)
+                                | ast::Expr::RefExpr(_)
+                                | ast::Expr::Literal(_)
+                                | ast::Expr::TupleExpr(_)
+                                | ast::Expr::ArrayExpr(_)
+                                | ast::Expr::ParenExpr(_)
+                                | ast::Expr::PathExpr(_)
+                                | ast::Expr::BlockExpr(_)
+                                | ast::Expr::EffectExpr(_),
+                        ) || matches!(
+                            usage_parent,
+                            ast::Expr::CallExpr(_)
+                                | ast::Expr::TupleExpr(_)
+                                | ast::Expr::ArrayExpr(_)
+                                | ast::Expr::ParenExpr(_)
+                                | ast::Expr::ForExpr(_)
+                                | ast::Expr::WhileExpr(_)
+                                | ast::Expr::BreakExpr(_)
+                                | ast::Expr::ReturnExpr(_)
+                                | ast::Expr::MatchExpr(_)
+                        )),
+                    )
                 })
                 .collect::<Option<_>>()
                 .map(|b| (file_id, b))
diff --git a/crates/ide_assists/src/tests.rs b/crates/ide_assists/src/tests.rs
index 60cecd94c..4e96ff1ec 100644
--- a/crates/ide_assists/src/tests.rs
+++ b/crates/ide_assists/src/tests.rs
@@ -35,6 +35,7 @@ pub(crate) fn with_single_file(text: &str) -> (RootDatabase, FileId) {
     RootDatabase::with_single_file(text)
 }
 
+#[track_caller]
 pub(crate) fn check_assist(assist: Handler, ra_fixture_before: &str, ra_fixture_after: &str) {
     let ra_fixture_after = trim_indent(ra_fixture_after);
     check(assist, ra_fixture_before, ExpectedResult::After(&ra_fixture_after), None);
@@ -179,9 +180,10 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult, assist_label:
             "unresolved assist should not contain source changes"
         ),
         (Some(_), ExpectedResult::NotApplicable) => panic!("assist should not be applicable!"),
-        (None, ExpectedResult::After(_))
-        | (None, ExpectedResult::Target(_))
-        | (None, ExpectedResult::Unresolved) => {
+        (
+            None,
+            ExpectedResult::After(_) | ExpectedResult::Target(_) | ExpectedResult::Unresolved,
+        ) => {
             panic!("code action is not applicable")
         }
         (None, ExpectedResult::NotApplicable) => (),