chore: custom configuration for formatter tests (#3202)

Co-authored-by: kevaundray <[email protected]>

tooling/nargo_fmt/build.rs

@@ -40,6 +40,12 @@ fn generate_formatter_tests(test_file: &mut File, test_data_dir: &Path) {
         let input_source_path = file.path();
         let input_source = std::fs::read_to_string(input_source_path).unwrap();
 
+        let config = input_source
+            .lines()
+            .flat_map(|line| line.strip_prefix("//@"))
+            .collect::<Vec<_>>()
+            .join("\n");
+
         let output_source_path = outputs_dir.join(file_name);
         let output_source = std::fs::read_to_string(output_source_path).unwrap();
 
@@ -55,7 +61,7 @@ fn format_{test_name}() {{
     let (parsed_module, errors) = noirc_frontend::parse_program(&input);
     assert!(errors.is_empty());
 
-    let config = nargo_fmt::Config::default();
+    let config = nargo_fmt::Config::of("{config}").unwrap();
     let fmt_text = nargo_fmt::format(&input, parsed_module, &config);
 
 

tooling/nargo_fmt/src/config.rs

@@ -45,23 +45,28 @@ config! {
     max_width: usize, 100, "Maximum width of each line";
     tab_spaces: usize, 4, "Number of spaces per tab";
     remove_nested_parens: bool, true, "Remove nested parens";
+    error_on_lost_comment: bool, true, "Error if unable to get comments";
     short_array_element_width_threshold: usize, 10, "Width threshold for an array element to be considered short";
     array_width: usize, 100, "Maximum width of an array literal before falling back to vertical formatting";
     single_line_if_else_max_width: usize, 50, "Maximum line length for single line if-else expressions";
 }
 
 impl Config {
     pub fn read(path: &Path) -> Result<Self, ConfigError> {
-        let mut config = Self::default();
         let config_path = path.join("noirfmt.toml");
 
-        let raw_toml = match std::fs::read_to_string(&config_path) {
-            Ok(t) => t,
-            Err(err) if err.kind() == std::io::ErrorKind::NotFound => String::new(),
+        let input = match std::fs::read_to_string(&config_path) {
+            Ok(input) => input,
+            Err(cause) if cause.kind() == std::io::ErrorKind::NotFound => String::new(),
             Err(cause) => return Err(ConfigError::ReadFailed(config_path, cause)),
         };
-        let toml = toml::from_str(&raw_toml).map_err(ConfigError::MalformedFile)?;
 
+        Self::of(&input)
+    }
+
+    pub fn of(s: &str) -> Result<Self, ConfigError> {
+        let mut config = Self::default();
+        let toml = toml::from_str(s).map_err(ConfigError::MalformedFile)?;
         config.fill_from_toml(toml);
         Ok(config)
     }

tooling/nargo_fmt/src/utils.rs

@@ -4,14 +4,6 @@ use noirc_frontend::lexer::Lexer;
 use noirc_frontend::token::Token;
 use noirc_frontend::{Expression, Ident};
 
-pub(crate) fn recover_comment_removed(original: &str, new: String) -> String {
-    if changed_comment_content(original, &new) {
-        original.to_string()
-    } else {
-        new
-    }
-}
-
 pub(crate) fn changed_comment_content(original: &str, new: &str) -> bool {
     comments(original).ne(comments(new))
 }

tooling/nargo_fmt/src/visitor.rs

@@ -89,7 +89,15 @@ impl<'me> FmtVisitor<'me> {
 
     #[track_caller]
     fn push_rewrite(&mut self, rewrite: String, span: Span) {
-        let rewrite = utils::recover_comment_removed(self.slice(span), rewrite);
+        let original = self.slice(span);
+        let changed_comment_content = utils::changed_comment_content(original, &rewrite);
+
+        if changed_comment_content && self.config.error_on_lost_comment {
+            panic!("not formatted because a comment would be lost: {rewrite:?}");
+        }
+
+        let rewrite = if changed_comment_content { original.to_string() } else { rewrite };
+
         self.format_missing_indent(span.start(), true);
         self.push_str(&rewrite);
     }

tooling/nargo_fmt/src/visitor/expr.rs

@@ -13,10 +13,8 @@ use crate::{
 impl FmtVisitor<'_> {
     pub(crate) fn visit_expr(&mut self, expr: Expression, expr_type: ExpressionType) {
         let span = expr.span;
-
         let rewrite = self.format_expr(expr, expr_type);
         self.push_rewrite(rewrite, span);
-
         self.last_position = span.end();
     }
 

tooling/nargo_fmt/tests/expected/if.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn main() {
     let (x,y) = if is_square(gx1) {
         (x1, sqrt(gx1))

tooling/nargo_fmt/tests/expected/infix.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn foo() {
     40 + 2;
     !40 + 2;

tooling/nargo_fmt/tests/expected/let.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn let_() {
     let fn_call = my_function(some_function(10, "arg1", another_function()), another_func(20, some_function(), 30));
     let array = [[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12]], [[13, 14, 15], [16, 17, 18]]];

tooling/nargo_fmt/tests/expected/literals.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn main() {
     [1, 2, 3, 4, 5];
 

tooling/nargo_fmt/tests/expected/nested_parens.nr

@@ -0,0 +1,5 @@
+//@remove_nested_parens=false
+fn main() {
+    ((()));
+    ((((((((()))))))));
+}

tooling/nargo_fmt/tests/expected/unary_operators.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn main() {
     -1;
     -/*test*/1;

tooling/nargo_fmt/tests/input/if.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn main() {
     let (x,y) = if is_square(gx1) {(x1, sqrt(gx1))} else {(x2, sqrt(gx2))};
 

tooling/nargo_fmt/tests/input/infix.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn foo() {
     40 + 2;
     !40+2;

tooling/nargo_fmt/tests/input/let.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn let_() {
     let fn_call = my_function(some_function( 10, "arg1", another_function() ),another_func (20, some_function() , 30 ));
     let array = [[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12]], [[13, 14, 15], [16, 17, 18]]];

tooling/nargo_fmt/tests/input/literals.nr

@@ -1,4 +1,4 @@
-
+//@error_on_lost_comment=false
 fn main() {
     [1,2,3,4,5];
 

tooling/nargo_fmt/tests/input/nested_parens.nr

@@ -0,0 +1,5 @@
+//@remove_nested_parens=false
+fn main() {
+    ((()));
+    ((((((((()))))))));
+}

tooling/nargo_fmt/tests/input/unary_operators.nr

@@ -1,3 +1,4 @@
+//@error_on_lost_comment=false
 fn main() {
     -1;
 -/*test*/1;