fix(semantic-token): highlight mapped alias type parameters

Author: xuhuanzy

crates/emmylua_ls/src/handlers/semantic_token/build_semantic_tokens.rs

@@ -11,9 +11,9 @@ use emmylua_code_analysis::{
 };
 use emmylua_parser::{
     LuaAst, LuaAstNode, LuaAstToken, LuaCallArgList, LuaCallExpr, LuaComment, LuaDocFieldKey,
-    LuaDocGenericDecl, LuaDocGenericDeclList, LuaDocObjectFieldKey, LuaExpr, LuaGeneralToken,
-    LuaKind, LuaLiteralToken, LuaNameToken, LuaSyntaxKind, LuaSyntaxNode, LuaSyntaxToken,
-    LuaTokenKind, LuaVarExpr,
+    LuaDocGenericDecl, LuaDocGenericDeclList, LuaDocMappedKey, LuaDocObjectFieldKey, LuaExpr,
+    LuaGeneralToken, LuaKind, LuaLiteralToken, LuaNameToken, LuaSyntaxKind, LuaSyntaxNode,
+    LuaSyntaxToken, LuaTokenKind, LuaVarExpr,
 };
 use emmylua_parser_desc::{CodeBlockHighlightKind, DescItem, DescItemKind};
 use lsp_types::SemanticToken;
@@ -342,6 +342,17 @@ fn build_node_semantic_token(
             if let Some(generic_decl_list) = doc_alias.get_generic_decl_list() {
                 render_type_parameter_list(builder, &generic_decl_list);
             }
+            if let Some(alias_type) = doc_alias.get_type() {
+                for mapped_key in alias_type
+                    .syntax()
+                    .descendants()
+                    .filter_map(LuaDocMappedKey::cast)
+                {
+                    if let Some(type_decl) = mapped_key.child::<LuaDocGenericDecl>() {
+                        render_type_parameter(builder, &type_decl);
+                    }
+                }
+            }
         }
         LuaAst::LuaDocTagField(doc_field) => {
             if let Some(LuaDocFieldKey::Name(name)) = doc_field.get_field_key() {

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

@@ -105,6 +105,27 @@ m.foo()
         Ok(())
     }
 
+    #[gtest]
+    fn test_mapped_type_parameter_is_highlighted() -> Result<()> {
+        let mut ws = ProviderVirtualWorkspace::new();
+        let data = ws.get_semantic_token_data(
+            r#"---@alias Pick<T, K> {[P in K]: T[P];}
+"#,
+        )?;
+        let tokens = decode(&data);
+        let typ = SemanticTokenTypeKind::Type.to_u32();
+        let declaration = SemanticTokenModifierKind::DECLARATION.to_u32();
+
+        verify_that!(
+            &tokens,
+            all![
+                contains(eq(&(0, 23, 1, typ, declaration))),
+                contains(eq(&(0, 34, 1, typ, 0))),
+            ]
+        )?;
+        Ok(())
+    }
+
     #[gtest]
     fn test_local_function() -> Result<()> {
         let mut ws = ProviderVirtualWorkspace::new();