4 files changed, 17 insertions, 2 deletions

diff --git a/crates/ide_db/src/apply_change.rs b/crates/ide_db/src/apply_change.rs
index 23974cff8..104ee113f 100644
--- a/crates/ide_db/src/apply_change.rs
+++ b/crates/ide_db/src/apply_change.rs
@@ -32,7 +32,7 @@ struct RootChange {
 
 impl fmt::Debug for RootChange {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        fmt.debug_struct("AnalysisChange")
+        fmt.debug_struct("RootChange")
             .field("added", &self.added.len())
             .field("removed", &self.removed.len())
             .finish()
diff --git a/crates/ide_db/src/helpers.rs b/crates/ide_db/src/helpers.rs
index bc7aee110..f9de8ce0e 100644
--- a/crates/ide_db/src/helpers.rs
+++ b/crates/ide_db/src/helpers.rs
@@ -45,6 +45,10 @@ impl FamousDefs<'_, '_> {
         self.find_crate("core")
     }
 
+    pub fn core_cmp_Ord(&self) -> Option<Trait> {
+        self.find_trait("core:cmp:Ord")
+    }
+
     pub fn core_convert_From(&self) -> Option<Trait> {
         self.find_trait("core:convert:From")
     }
diff --git a/crates/ide_db/src/helpers/famous_defs_fixture.rs b/crates/ide_db/src/helpers/famous_defs_fixture.rs
index 5e88de64d..bb4e9666b 100644
--- a/crates/ide_db/src/helpers/famous_defs_fixture.rs
+++ b/crates/ide_db/src/helpers/famous_defs_fixture.rs
@@ -1,5 +1,15 @@
 //- /libcore.rs crate:core
 //! Signatures of traits, types and functions from the core lib for use in tests.
+pub mod cmp {
+
+    pub trait Ord {
+        fn cmp(&self, other: &Self) -> Ordering;
+        fn max(self, other: Self) -> Self;
+        fn min(self, other: Self) -> Self;
+        fn clamp(self, min: Self, max: Self) -> Self;
+    }
+}
+
 pub mod convert {
     pub trait From<T> {
         fn from(t: T) -> Self;
@@ -109,6 +119,7 @@ pub mod option {
 
 pub mod prelude {
     pub use crate::{
+        cmp::Ord,
         convert::From,
         default::Default,
         iter::{IntoIterator, Iterator},
diff --git a/crates/ide_db/src/source_change.rs b/crates/ide_db/src/source_change.rs
index f76bac151..b36455d49 100644
--- a/crates/ide_db/src/source_change.rs
+++ b/crates/ide_db/src/source_change.rs
@@ -1,7 +1,7 @@
 //! This modules defines type to represent changes to the source code, that flow
 //! from the server to the client.
 //!
-//! It can be viewed as a dual for `AnalysisChange`.
+//! It can be viewed as a dual for `Change`.
 
 use std::{
     collections::hash_map::Entry,