Refactor how new lines after extends are inserted

queries/gdscript.scm

@@ -85,11 +85,8 @@
 (class_definition) @prepend_hardline
 (class_definition extends: (extends_statement "extends" @prepend_space))
 
-(source
-    (class_name_statement
-        extends: (extends_statement) @append_delimiter @append_hardline (#delimiter! "\n")))
-(source
-    (extends_statement) @append_delimiter @append_hardline (#delimiter! "\n"))
+(source (class_name_statement extends: (extends_statement) @append_hardline))
+(source (extends_statement) @append_hardline)
 (source (class_name_statement (name) @append_hardline))
 
 ; CONST DEFINITIONS

src/formatter.rs

@@ -14,7 +14,7 @@
 //! rules have too much performance overhead when applied through Topiary.
 use std::{collections::VecDeque, io::BufWriter};
 
-use regex::{Regex, RegexBuilder};
+use regex::{Regex, RegexBuilder, Replacer};
 use topiary_core::{Language, Operation, TopiaryQuery, formatter_tree};
 use tree_sitter::{Parser, Point, Query, QueryCursor, StreamingIterator, Tree};
 
@@ -126,14 +126,15 @@ impl Formatter {
     /// pre-applying rules that could be performance-intensive through topiary.
     #[inline(always)]
     fn preprocess(&mut self) -> &mut Self {
-        self.remove_newlines_after_extends_statement()
+        self
     }
 
     /// This function runs over the content after going through topiary. We use it
     /// to clean up/balance out the output.
     #[inline(always)]
     fn postprocess(&mut self) -> &mut Self {
-        self.fix_dangling_semicolons()
+        self.add_newlines_after_extends_statement()
+            .fix_dangling_semicolons()
             .fix_dangling_commas()
             .remove_trailing_commas_from_preload()
             .postprocess_tree_sitter()
@@ -154,23 +155,40 @@ impl Formatter {
         Ok(self.content)
     }
 
-    /// This function removes additional new line characters after `extends_statement`.
+    /// This function adds additional new line characters after `extends_statement`.
     #[inline(always)]
-    fn remove_newlines_after_extends_statement(&mut self) -> &mut Self {
+    fn add_newlines_after_extends_statement(&mut self) -> &mut Self {
         // This regex matches substrings which:
-        // - must NOT contain "#" or "\n" characters between new line and "extends" keyword
-        // - must end with at least one new line character
+        // - must start wtih "extends" keyword
         // - must contain `extends_name` character sequence that satisfies one of the following conditions:
         //   - consists out of alphanumeric characters
         //   - consists out of any characters (except new lines) between double quotes
+        // - must contain at least one new line character between `extends_name` and optional doc comment
+        // - may contain multiple doc comment lines that starts with `##` and ends with a new line character
         let re = RegexBuilder::new(
-            r#"(?P<extends_line>^[^#\n]*extends )(?P<extends_name>([a-zA-Z0-9]+|".*?"))\n(\n*)"#,
+            r#"(?P<extends_line>^extends )(?P<extends_name>([a-zA-Z0-9]+|".*?"))\n+(?P<doc>(?:^##.*\n)*)(?P<EOF>\z)?"#,
         )
         .multi_line(true)
         .build()
         .expect("regex should compile");
 
-        self.regex_replace_all_outside_strings(re, "$extends_line$extends_name\n");
+        self.regex_replace_all_outside_strings(re, |caps: &regex::Captures| {
+            let extends_line = caps.name("extends_line").unwrap().as_str();
+            let extends_name = caps.name("extends_name").unwrap().as_str();
+            let doc = caps
+                .name("doc")
+                .map(|m| m.as_str())
+                .unwrap_or_default()
+                .trim_end(); // remove last new line from doc comment because we add a new line manually
+            // insert new line only if we are not at the end of file
+            let blank_new_line = if caps.name("EOF").is_some() { "" } else { "\n" };
+
+            format!(
+                "{}{}\n{}{}",
+                extends_line, extends_name, doc, blank_new_line
+            )
+        });
+
         self
     }
 
@@ -233,7 +251,7 @@ impl Formatter {
     /// outside of strings (simple or multiline).
     /// Use this to make post-processing changes needed for formatting but that
     /// shouldn't affect strings in the source code.
-    fn regex_replace_all_outside_strings(&mut self, re: Regex, rep: &str) {
+    fn regex_replace_all_outside_strings<R: Replacer>(&mut self, re: Regex, mut rep: R) {
         let mut iter = re.captures_iter(&self.content).peekable();
         if iter.peek().is_none() {
             return;
@@ -260,7 +278,7 @@ impl Formatter {
             }
 
             let mut replacement = String::new();
-            capture.expand(rep, &mut replacement);
+            rep.replace_append(&capture, &mut replacement);
 
             let new_end_byte = start_byte + replacement.len();
 

tests/expected/class_doc_comment.gd

@@ -0,0 +1,24 @@
+class_name Player
+extends CharacterBody2D
+## A brief description of the class's role and functionality.
+##
+## The description of script
+class_name Player
+extends CharacterBody2D
+## A brief description of the class's role and functionality.
+##
+## The description of script
+class_name Player
+extends CharacterBody2D
+## A brief description of the class's role and functionality.
+##
+## The description of script
+
+var a = 10
+class_name Player
+extends CharacterBody2D
+## A brief description of the class's role and functionality.
+##
+## The description of script
+
+var a = 10

tests/input/class_doc_comment.gd

@@ -0,0 +1,23 @@
+class_name Player extends CharacterBody2D
+
+## A brief description of the class's role and functionality.
+##
+## The description of script
+class_name Player extends CharacterBody2D
+## A brief description of the class's role and functionality.
+##
+## The description of script
+class_name Player extends CharacterBody2D
+## A brief description of the class's role and functionality.
+##
+## The description of script
+
+var a = 10
+class_name Player
+extends CharacterBody2D
+
+## A brief description of the class's role and functionality.
+##
+## The description of script
+
+var a = 10