From fec5ff989025ee01f7659da28e95d0fe0feafa86 Mon Sep 17 00:00:00 2001
From: ponyii <ponyii@protonmail.com>
Date: Tue, 15 Aug 2023 20:26:42 +0400
Subject: [PATCH] start hovering default values of generic constants

---
 crates/hir/src/display.rs     |  5 ++++
 crates/ide/src/hover/tests.rs | 45 ++++++++++++++++++++++++++++++++++-
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/crates/hir/src/display.rs b/crates/hir/src/display.rs
index a701eb0119..ac171026d5 100644
--- a/crates/hir/src/display.rs
+++ b/crates/hir/src/display.rs
@@ -366,6 +366,11 @@ fn write_generic_params(
                     delim(f)?;
                     write!(f, "const {}: ", name.display(f.db.upcast()))?;
                     c.ty.hir_fmt(f)?;
+
+                    if let Some(default) = &c.default {
+                        f.write_str(" = ")?;
+                        write!(f, "{}", default.display(f.db.upcast()))?;
+                    }
                 }
             }
         }
diff --git a/crates/ide/src/hover/tests.rs b/crates/ide/src/hover/tests.rs
index 541cce8c5b..d0f9f7b0e1 100644
--- a/crates/ide/src/hover/tests.rs
+++ b/crates/ide/src/hover/tests.rs
@@ -3335,7 +3335,50 @@ struct S$0T<const C: usize = 1, T = Foo>(T);
             ```
 
             ```rust
-            struct ST<const C: usize, T = Foo>
+            struct ST<const C: usize = 1, T = Foo>
+            ```
+        "#]],
+    );
+}
+
+#[test]
+fn const_generic_default_value() {
+    check(
+        r#"
+struct Foo;
+struct S$0T<const C: usize = {40 + 2}, T = Foo>(T);
+"#,
+        expect![[r#"
+            *ST*
+
+            ```rust
+            test
+            ```
+
+            ```rust
+            struct ST<const C: usize = {const}, T = Foo>
+            ```
+        "#]],
+    );
+}
+
+#[test]
+fn const_generic_default_value_2() {
+    check(
+        r#"
+struct Foo;
+const VAL = 1;
+struct S$0T<const C: usize = VAL, T = Foo>(T);
+"#,
+        expect![[r#"
+            *ST*
+
+            ```rust
+            test
+            ```
+
+            ```rust
+            struct ST<const C: usize = VAL, T = Foo>
             ```
         "#]],
     );