fix: properly handle nested strings of different types inside interpolations

Author: amaanq

grammar.js

@@ -1497,15 +1497,15 @@ module.exports = grammar({
     interpolated_string_expression: $ => choice(
       seq(
         alias($.interpolation_regular_start, $.interpolation_start),
-        '"',
+        alias($.interpolation_start_quote, '"'),
         repeat($._interpolated_string_content),
-        '"',
+        alias($.interpolation_end_quote, '"'),
       ),
       seq(
         alias($.interpolation_verbatim_start, $.interpolation_start),
-        '"',
+        alias($.interpolation_start_quote, '"'),
         repeat($._interpolated_verbatim_string_content),
-        '"',
+        alias($.interpolation_end_quote, '"'),
       ),
       seq(
         alias($.interpolation_raw_start, $.interpolation_start),

src/scanner.c

@@ -217,6 +217,7 @@ bool tree_sitter_c_sharp_external_scanner_scan(void *payload, TSLexer *lexer, co
             if (is_verbatim || lexer->lookahead == '@') {
                 if (lexer->lookahead == '@') {
                     advance(lexer);
+                    is_verbatim = true;
                 }
                 lexer->result_symbol = INTERPOLATION_VERBATIM_START;
                 interpolation.string_type = VERBATIM;
@@ -246,13 +247,20 @@ bool tree_sitter_c_sharp_external_scanner_scan(void *payload, TSLexer *lexer, co
     if (valid_symbols[INTERPOLATION_START_QUOTE] && scanner->interpolation_stack.size > 0) {
         Interpolation *current_interpolation = array_back(&scanner->interpolation_stack);
 
-        while (lexer->lookahead == '"') {
-            advance(lexer);
-            current_interpolation->quote_count++;
+        if (is_verbatim(current_interpolation) || is_regular(current_interpolation)) {
+            if (lexer->lookahead == '"') {
+                advance(lexer);
+                current_interpolation->quote_count++;
+            }
+        } else {
+            while (lexer->lookahead == '"') {
+                advance(lexer);
+                current_interpolation->quote_count++;
+            }
         }
 
         lexer->result_symbol = INTERPOLATION_START_QUOTE;
-        return current_interpolation->quote_count >= 3;
+        return current_interpolation->quote_count > 0;
     }
 
     if (valid_symbols[INTERPOLATION_END_QUOTE] && scanner->interpolation_stack.size > 0) {
@@ -302,20 +310,6 @@ bool tree_sitter_c_sharp_external_scanner_scan(void *payload, TSLexer *lexer, co
 
             if (brace_advanced == current_interpolation->open_brace_count) {
                 current_interpolation->open_brace_count = 0;
-                if (lexer->lookahead == '"') {
-                    if (is_regular(current_interpolation) || is_verbatim(current_interpolation)) {
-                        if (is_verbatim(current_interpolation)) {
-                            lexer->mark_end(lexer);
-                            advance(lexer);
-                            // double quote in verbatim does not signify end, unless it's a triple quote
-                            if (lexer->lookahead != '"') {
-                                array_pop(&scanner->interpolation_stack);
-                            }
-                        } else {
-                            array_pop(&scanner->interpolation_stack);
-                        }
-                    }
-                }
                 lexer->result_symbol = INTERPOLATION_CLOSE_BRACE;
                 return true;
             }
@@ -371,9 +365,6 @@ bool tree_sitter_c_sharp_external_scanner_scan(void *payload, TSLexer *lexer, co
                         advance(lexer);
                         continue;
                     }
-                    if (did_advance) {
-                        array_pop(&scanner->interpolation_stack);
-                    }
                     return did_advance;
                 }
 
@@ -395,9 +386,6 @@ bool tree_sitter_c_sharp_external_scanner_scan(void *payload, TSLexer *lexer, co
             // finally regular
             else if (is_regular(current_interpolation)) {
                 if (lexer->lookahead == '\\' || lexer->lookahead == '\n' || lexer->lookahead == '"') {
-                    if (did_advance && lexer->lookahead == '"') {
-                        array_pop(&scanner->interpolation_stack);
-                    }
                     lexer->mark_end(lexer);
                     return did_advance;
                 }

test/corpus/literals.txt

@@ -117,8 +117,6 @@ var x = $"""The point "{X}, {Y}" is
 
 var x = $"{{";
 
-var x = $@"""{foo}""";
-
 var x = $"""{bar}""";
 
 var x = """"baz"""";
@@ -131,6 +129,10 @@ var x = $""""
 var x = $@" ""hi"" ";
 var x = @$"""Hello"" {world}!";
 
+var s = $$"""
+{{ $" { 1 } " }}
+""";
+
 --------------------------------------------------------------------------------
 
 (compilation_unit
@@ -803,20 +805,6 @@ var x = @$"""Hello"" {world}!";
               (identifier)
               (interpolation_brace))
             (interpolation_quote))))))
-  (global_statement
-    (local_declaration_statement
-      (variable_declaration
-        type: (implicit_type)
-        (variable_declarator
-          name: (identifier)
-          (interpolated_string_expression
-            (interpolation_start)
-            (interpolation_quote)
-            (interpolation
-              (interpolation_brace)
-              (identifier)
-              (interpolation_brace))
-            (interpolation_quote))))))
   (global_statement
     (local_declaration_statement
       (variable_declaration
@@ -860,4 +848,27 @@ var x = @$"""Hello"" {world}!";
               (interpolation_brace)
               (identifier)
               (interpolation_brace))
-            (string_content)))))))
+            (string_content))))))
+  (global_statement
+    (local_declaration_statement
+      (variable_declaration
+        type: (implicit_type)
+        (variable_declarator
+          name: (identifier)
+          (interpolated_string_expression
+            (interpolation_start)
+            (interpolation_quote)
+            (string_content)
+            (interpolation
+              (interpolation_brace)
+              (interpolated_string_expression
+                (interpolation_start)
+                (string_content)
+                (interpolation
+                  (interpolation_brace)
+                  (integer_literal)
+                  (interpolation_brace))
+                (string_content))
+              (interpolation_brace))
+            (string_content)
+            (interpolation_quote)))))))