fix: render alias call and generic declaration syntax in hovers

Author: xuhuanzy

crates/emmylua_code_analysis/src/db_index/type/humanize_type.rs

@@ -259,13 +259,35 @@ impl<'a> TypeHumanizer<'a> {
         };
 
         w.write_str(&full_name)?;
+        if generic.is_empty() {
+            return Ok(());
+        }
+
         w.write_char('<')?;
-        for (i, param) in generic.iter().enumerate() {
-            if i > 0 {
-                w.write_str(", ")?;
+        let saved = self.level;
+        self.level = self.child_level();
+        let result = (|| {
+            for (i, param) in generic.iter().enumerate() {
+                if i > 0 {
+                    w.write_str(", ")?;
+                }
+                if param.is_const {
+                    w.write_str("const ")?;
+                }
+                w.write_str(&param.name)?;
+                if let Some(constraint) = &param.constraint {
+                    w.write_str(" extends ")?;
+                    self.write_type(constraint, w)?;
+                }
+                if let Some(default_type) = &param.default {
+                    w.write_str(" = ")?;
+                    self.write_type(default_type, w)?;
+                }
             }
-            w.write_str(&param.name)?;
-        }
+            Ok(())
+        })();
+        self.level = saved;
+        result?;
         w.write_char('>')
     }
 
@@ -515,29 +537,56 @@ impl<'a> TypeHumanizer<'a> {
     // ─── Call (alias call) ──────────────────────────────────────────
 
     fn write_call_type<W: Write>(&mut self, inner: &LuaAliasCallType, w: &mut W) -> fmt::Result {
-        let basic = match inner.get_call_kind() {
-            LuaAliasCallKind::Sub => "sub",
-            LuaAliasCallKind::Add => "add",
-            LuaAliasCallKind::KeyOf => "keyof",
-            LuaAliasCallKind::Extends => "extends",
-            LuaAliasCallKind::Select => "select",
-            LuaAliasCallKind::Unpack => "unpack",
-            LuaAliasCallKind::Index => "index",
-            LuaAliasCallKind::RawGet => "rawget",
-            LuaAliasCallKind::Merge => "Merge",
-        };
-        w.write_str(basic)?;
-        w.write_char('<')?;
+        let operands = inner.get_operands();
         let saved = self.level;
         self.level = self.child_level();
-        for (i, ty) in inner.get_operands().iter().enumerate() {
-            if i > 0 {
-                w.write_char(',')?;
+        let result = (|| match inner.get_call_kind() {
+            LuaAliasCallKind::KeyOf => {
+                w.write_str("keyof ")?;
+                for (i, ty) in operands.iter().enumerate() {
+                    if i > 0 {
+                        w.write_char(',')?;
+                    }
+                    self.write_type(ty, w)?;
+                }
+                Ok(())
             }
-            self.write_type(ty, w)?;
-        }
+            LuaAliasCallKind::Extends if operands.len() == 2 => {
+                self.write_type(&operands[0], w)?;
+                w.write_str(" extends ")?;
+                self.write_type(&operands[1], w)
+            }
+            LuaAliasCallKind::Index if operands.len() == 2 => {
+                self.write_type(&operands[0], w)?;
+                w.write_char('[')?;
+                self.write_type(&operands[1], w)?;
+                w.write_char(']')
+            }
+            call_kind => {
+                let basic = match call_kind {
+                    LuaAliasCallKind::Sub => "sub",
+                    LuaAliasCallKind::Add => "add",
+                    LuaAliasCallKind::KeyOf => "keyof",
+                    LuaAliasCallKind::Extends => "extends",
+                    LuaAliasCallKind::Select => "select",
+                    LuaAliasCallKind::Unpack => "unpack",
+                    LuaAliasCallKind::Index => "index",
+                    LuaAliasCallKind::RawGet => "rawget",
+                    LuaAliasCallKind::Merge => "Merge",
+                };
+                w.write_str(basic)?;
+                w.write_char('<')?;
+                for (i, ty) in operands.iter().enumerate() {
+                    if i > 0 {
+                        w.write_char(',')?;
+                    }
+                    self.write_type(ty, w)?;
+                }
+                w.write_char('>')
+            }
+        })();
         self.level = saved;
-        w.write_char('>')
+        result
     }
 
     // ─── DocFunction ────────────────────────────────────────────────

crates/emmylua_ls/src/handlers/hover/humanize_type_decl.rs

@@ -14,8 +14,10 @@ pub fn build_type_decl_hover(
     let type_decl = db.get_type_index().get_type_decl(&type_decl_id)?;
     let type_description = if type_decl.is_alias() {
         if let Some(origin) = type_decl.get_alias_origin(db, None) {
+            let type_name =
+                humanize_type(db, &LuaType::Def(type_decl_id.clone()), RenderLevel::Normal);
             let origin_type = humanize_type(db, &origin, builder.detail_render_level);
-            format!("(alias) {} = {}", type_decl.get_name(), origin_type)
+            format!("(alias) {} = {}", type_name, origin_type)
         } else {
             "".to_string()
         }

crates/emmylua_ls/src/handlers/test/hover_test.rs

@@ -295,6 +295,63 @@ mod tests {
         Ok(())
     }
 
+    #[gtest]
+    fn test_hover_special_alias_call_type_syntax() -> Result<()> {
+        let mut ws = ProviderVirtualWorkspace::new();
+        check!(ws.check_hover(
+            r#"
+                ---@class KeyofHoverShape
+                ---@field name string
+
+                ---@type keyof KeyofHoverShape
+                local <??>key
+            "#,
+            VirtualHoverResult {
+                value: "```lua\nlocal key: keyof KeyofHoverShape\n```".to_string(),
+            },
+        ));
+
+        check!(ws.check_hover(
+            r#"
+                ---@class ExtendsHoverShape
+                ---@field name string
+
+                ---@type ExtendsHoverShape extends table
+                local <??>is_table
+            "#,
+            VirtualHoverResult {
+                value: "```lua\nlocal is_table: ExtendsHoverShape extends table\n```".to_string(),
+            },
+        ));
+
+        check!(ws.check_hover(
+            r#"
+                ---@alias AB<??>C<K extends keyof T, T> T[K]
+            "#,
+            VirtualHoverResult {
+                value: "```lua\n(alias) ABC<K extends keyof T, T> = T[K]\n```".to_string(),
+            },
+        ));
+
+        check!(
+            ws.check_hover(
+                r#"
+                ---@class BoxHoverShape
+                ---@field name string
+
+                ---@class BoxHoverShape<??>Box<K extends keyof BoxHoverShape, T>
+                ---@field value T
+            "#,
+                VirtualHoverResult {
+                    value:
+                        "```lua\n(class) BoxHoverShapeBox<K extends keyof BoxHoverShape, T>\n```"
+                            .to_string(),
+                },
+            )
+        );
+        Ok(())
+    }
+
     #[gtest]
     fn test_hover_narrowed_function_type() -> Result<()> {
         let mut ws = ProviderVirtualWorkspace::new();