3 files changed, 25 insertions, 41 deletions

diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index 33689e081..6df8181ed 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -26,25 +26,14 @@ fn test() {
 fn infer_async() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
-async fn foo() -> u64 {
-            128
-}
+//- minicore: future
+async fn foo() -> u64 { 128 }
 
 fn test() {
     let r = foo();
     let v = r.await;
     v;
 } //^ u64
-
-//- /core.rs crate:core
-#[prelude_import] use future::*;
-mod future {
-    #[lang = "future_trait"]
-    trait Future {
-        type Output;
-    }
-}
 "#,
     );
 }
@@ -53,24 +42,13 @@ mod future {
 fn infer_desugar_async() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
-async fn foo() -> u64 {
-            128
-}
+//- minicore: future
+async fn foo() -> u64 { 128 }
 
 fn test() {
     let r = foo();
     r;
 } //^ impl Future<Output = u64>
-
-//- /core.rs crate:core
-#[prelude_import] use future::*;
-mod future {
-    trait Future {
-        type Output;
-    }
-}
-
 "#,
     );
 }
@@ -79,7 +57,7 @@ mod future {
 fn infer_async_block() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
+//- minicore: future, option
 async fn test() {
     let a = async { 42 };
     a;
@@ -91,7 +69,7 @@ async fn test() {
     b;
 //  ^ ()
     let c = async {
-        let y = Option::None;
+        let y = None;
         y
     //  ^ Option<u64>
     };
@@ -99,18 +77,6 @@ async fn test() {
     c;
 //  ^ impl Future<Output = Option<u64>>
 }
-
-enum Option<T> { None, Some(T) }
-
-//- /core.rs crate:core
-#[prelude_import] use future::*;
-mod future {
-    #[lang = "future_trait"]
-    trait Future {
-        type Output;
-    }
-}
-
 "#,
     );
 }
diff --git a/crates/test_utils/src/fixture.rs b/crates/test_utils/src/fixture.rs
index 779146084..6ba112de8 100644
--- a/crates/test_utils/src/fixture.rs
+++ b/crates/test_utils/src/fixture.rs
@@ -198,6 +198,7 @@ impl MiniCore {
         self.activated_flags.iter().any(|it| it == flag)
     }
 
+    #[track_caller]
     fn assert_valid_flag(&self, flag: &str) {
         if !self.valid_flags.iter().any(|it| it == flag) {
             panic!("invalid flag: {:?}, valid flags: {:?}", flag, self.valid_flags);
@@ -299,6 +300,7 @@ impl MiniCore {
             let skip = if flag == "" {
                 false
             } else {
+                assert!(!flag.starts_with(' '), "region marker starts with a space: {:?}", flag);
                 self.assert_valid_flag(flag);
                 !self.has_flag(flag)
             };
diff --git a/crates/test_utils/src/minicore.rs b/crates/test_utils/src/minicore.rs
index 127d06e59..cb18c8796 100644
--- a/crates/test_utils/src/minicore.rs
+++ b/crates/test_utils/src/minicore.rs
@@ -16,6 +16,7 @@
 //!     coerce_unsized: unsize
 //!     pin:
 //!     future: pin
+//!     option:
 
 pub mod marker {
     // region:sized
@@ -115,6 +116,17 @@ pub mod slice {
 }
 // endregion:slice
 
+// region:option
+pub mod option {
+    pub enum Option<T> {
+        #[lang = "None"]
+        None,
+        #[lang = "Some"]
+        Some(T),
+    }
+}
+// endregion:option
+
 // region:pin
 pub mod pin {
     #[lang = "pin"]
@@ -127,7 +139,10 @@ pub mod pin {
 
 // region:future
 pub mod future {
-    use crate::{pin::Pin, task::{Poll, Context}};
+    use crate::{
+        pin::Pin,
+        task::{Context, Poll},
+    };
 
     #[lang = "future_trait"]
     pub trait Future {
@@ -153,6 +168,7 @@ pub mod task {
 pub mod prelude {
     pub mod v1 {
         pub use crate::marker::Sized; // :sized
+        pub use crate::option::Option::{self, None, Some}; // :option
     }
 
     pub mod rust_2015 {