fix(formatter): algin printing comments behavior with prettier for some nodes (#12420)

Our Rust side AST is different from `prettier`, so we should skip some nodes to not print comments, which aligns with the Prettier behavior.

Author: Dunqing

crates/oxc_formatter/src/generated/ast_nodes.rs

@@ -4814,7 +4814,7 @@ impl<'a> AstNode<'a, AssignmentExpression<'a>> {
 
     #[inline]
     pub fn right(&self) -> &AstNode<'a, Expression<'a>> {
-        let following_node = self.following_node;
+        let following_node = None;
         self.allocator.alloc(AstNode {
             inner: &self.inner.right,
             allocator: self.allocator,
@@ -5971,7 +5971,7 @@ impl<'a> AstNode<'a, ExpressionStatement<'a>> {
 
     #[inline]
     pub fn expression(&self) -> &AstNode<'a, Expression<'a>> {
-        let following_node = self.following_node;
+        let following_node = None;
         self.allocator.alloc(AstNode {
             inner: &self.inner.expression,
             allocator: self.allocator,
@@ -7344,7 +7344,7 @@ impl<'a> AstNode<'a, FormalParameters<'a>> {
 
     #[inline]
     pub fn rest(&self) -> Option<&AstNode<'a, BindingRestElement<'a>>> {
-        let following_node = self.following_node;
+        let following_node = None;
         self.allocator
             .alloc(self.inner.rest.as_ref().map(|inner| AstNode {
                 inner: inner.as_ref(),

crates/oxc_formatter/src/generated/format.rs

@@ -913,10 +913,7 @@ impl<'a> Format<'a, FormatFunctionOptions> for AstNode<'a, Function<'a>> {
 
 impl<'a> Format<'a> for AstNode<'a, FormalParameters<'a>> {
     fn fmt(&self, f: &mut Formatter<'_, 'a>) -> FormatResult<()> {
-        self.format_leading_comments(f)?;
-        let result = self.write(f);
-        self.format_trailing_comments(f)?;
-        result
+        self.write(f)
     }
 }
 

tasks/ast_tools/src/generators/formatter/ast_nodes.rs

@@ -18,6 +18,11 @@ pub fn get_node_type(ty: &TokenStream) -> TokenStream {
 
 const FORMATTER_CRATE_PATH: &str = "crates/oxc_formatter";
 
+/// Based on the printing comments algorithm, the last child of these AST nodes don't need to print comments.
+/// Without following nodes could lead to only print comments that before the end of the node, which is what we want.
+const AST_NODE_WITHOUT_FOLLOWING_NODE_LIST: &[&str] =
+    &["ExpressionStatement", "AssignmentExpression", "FormalParameters"];
+
 pub struct FormatterAstNodesGenerator;
 
 define_generator!(FormatterAstNodesGenerator);
@@ -255,8 +260,16 @@ fn generate_struct_impls(struct_def: &StructDef, schema: &Schema) -> TokenStream
                 quote! { &self.inner.#field_name }
             };
 
-            let mut following_node = quote! {
-                self.following_node
+            let mut following_node = if index == fields.len() - 1
+                && AST_NODE_WITHOUT_FOLLOWING_NODE_LIST.contains(&struct_def.name.as_str())
+            {
+                quote! {
+                    None
+                }
+            } else {
+                quote! {
+                    self.following_node
+                }
             };
 
             let mut next_field_index = index + 1;

tasks/ast_tools/src/generators/formatter/format.rs

@@ -13,6 +13,9 @@ use crate::{
 
 const FORMATTER_CRATE_PATH: &str = "crates/oxc_formatter";
 
+/// Based on the prettier printing comments algorithm, these nodes don't need to print comments.
+const AST_NODE_WITHOUT_PRINTING_COMMENTS_LIST: &[&str] = &["FormalParameters"];
+
 const NEEDS_PARENTHESES: &[&str] = &[
     "Class",
     "Function",
@@ -96,16 +99,17 @@ fn implementation(type_def: &TypeDef, schema: &Schema) -> TokenStream {
     }
 
     let is_program = type_def.as_struct().is_some_and(|s| s.name == "Program");
+    let do_not_print_comment = AST_NODE_WITHOUT_PRINTING_COMMENTS_LIST.contains(&type_def.name());
 
-    let leading_comments = if type_def.is_enum() || is_program {
+    let leading_comments = if type_def.is_enum() || is_program || do_not_print_comment {
         quote! {}
     } else {
         quote! {
             self.format_leading_comments(f)?;
         }
     };
 
-    let trailing_comments = if type_def.is_enum() {
+    let trailing_comments = if type_def.is_enum() || do_not_print_comment {
         quote! {}
     } else if is_program {
         quote! {

tasks/prettier_conformance/snapshots/prettier.js.snap.md

@@ -1,13 +1,12 @@
-js compatibility: 394/699 (56.37%)
+js compatibility: 400/699 (57.22%)
 
 # Failed
 
 | Spec path | Failed or Passed | Match ratio |
 | :-------- | :--------------: | :---------: |
-| js/arrays/preserve_empty_lines.js | 💥 | 97.30% |
 | js/arrow-call/arrow_call.js | 💥💥💥 | 94.85% |
 | js/arrows/call.js | 💥💥 | 75.68% |
-| js/arrows/comment.js | 💥💥 | 63.75% |
+| js/arrows/comment.js | 💥💥 | 94.55% |
 | js/arrows/curried.js | 💥💥 | 92.55% |
 | js/arrows/currying-4.js | 💥💥 | 94.34% |
 | js/arrows/issue-1389-curry.js | 💥💥 | 86.96% |
@@ -20,12 +19,11 @@ js compatibility: 394/699 (56.37%)
 | js/assignment/issue-2482-2.js | 💥 | 62.50% |
 | js/assignment/issue-7572.js | 💥 | 72.73% |
 | js/assignment/sequence.js | 💥 | 71.43% |
-| js/assignment-comments/function.js | 💥 | 92.73% |
+| js/assignment-comments/function.js | 💥 | 78.18% |
 | js/async/inline-await.js | 💥 | 25.00% |
 | js/async/nested.js | 💥 | 16.67% |
 | js/binary-expressions/arrow.js | 💥 | 66.67% |
 | js/binary-expressions/comment.js | 💥 | 86.36% |
-| js/binary-expressions/in_instanceof.js | 💥 | 97.96% |
 | js/binary-expressions/inline-jsx.js | 💥 | 40.00% |
 | js/binary-expressions/inline-object-array.js | 💥 | 85.71% |
 | js/binary-expressions/jsx_parent.js | 💥 | 33.85% |
@@ -45,6 +43,7 @@ js compatibility: 394/699 (56.37%)
 | js/chain-expression/test-3.js | 💥 | 75.00% |
 | js/chain-expression/test.js | 💥 | 25.00% |
 | js/class-comment/class-property.js | 💥 | 30.77% |
+| js/class-comment/misc.js | 💥 | 72.73% |
 | js/class-comment/superclass.js | 💥 | 57.83% |
 | js/class-extends/complex.js | 💥 | 89.47% |
 | js/class-extends/extends.js | 💥 | 94.74% |
@@ -54,36 +53,35 @@ js compatibility: 394/699 (56.37%)
 | js/classes/method.js | 💥 | 71.43% |
 | js/classes/property.js | 💥 | 62.86% |
 | js/classes-private-fields/with_comments.js | 💥💥 | 30.77% |
-| js/comments/15661.js | 💥💥 | 46.15% |
+| js/comments/15661.js | 💥💥 | 53.63% |
 | js/comments/16398.js | 💥💥 | 80.00% |
 | js/comments/blank.js | 💥💥 | 95.24% |
 | js/comments/call_comment.js | 💥💥 | 90.91% |
 | js/comments/dangling.js | 💥💥 | 93.33% |
 | js/comments/dangling_array.js | 💥💥 | 25.00% |
 | js/comments/dangling_for.js | 💥💥 | 22.22% |
-| js/comments/dynamic_imports.js | 💥💥 | 66.67% |
-| js/comments/empty-statements.js | 💥💥 | 87.88% |
+| js/comments/dynamic_imports.js | 💥💥 | 71.43% |
+| js/comments/empty-statements.js | 💥💥 | 90.91% |
 | js/comments/export-and-import.js | 💥💥 | 78.05% |
 | js/comments/export.js | 💥💥 | 84.93% |
-| js/comments/function-declaration.js | 💥💥 | 67.77% |
+| js/comments/function-declaration.js | 💥💥 | 66.67% |
 | js/comments/if.js | 💥💥 | 38.16% |
 | js/comments/issue-3532.js | 💥💥 | 80.82% |
-| js/comments/issues.js | 💥💥 | 73.68% |
+| js/comments/issues.js | 💥💥 | 74.63% |
 | js/comments/jsdoc-nestled-dangling.js | 💥💥 | 93.02% |
 | js/comments/jsdoc-nestled.js | 💥💥 | 89.29% |
 | js/comments/jsdoc.js | 💥💥 | 47.83% |
 | js/comments/jsx.js | 💥💥 | 41.63% |
 | js/comments/last-arg.js | 💥💥 | 80.65% |
-| js/comments/multi-comments-on-same-line.js | 💥✨ | 42.78% |
-| js/comments/multi-comments.js | 💥✨ | 36.84% |
+| js/comments/multi-comments.js | 💥✨ | 44.74% |
 | js/comments/return-statement.js | 💥💥 | 52.32% |
 | js/comments/tagged-template-literal.js | 💥💥 | 69.23% |
 | js/comments/template-literal.js | 💥💥 | 30.43% |
 | js/comments/trailing_space.js | 💥💥 | 60.00% |
 | js/comments/try.js | 💥💥 | 71.43% |
 | js/comments/variable_declarator.js | 💥✨ | 49.31% |
 | js/comments/while.js | 💥💥 | 62.75% |
-| js/comments/flow-types/inline.js | 💥 | 53.33% |
+| js/comments/flow-types/inline.js | 💥 | 62.50% |
 | js/comments/function/between-parentheses-and-function-body.js | 💥 | 55.17% |
 | js/comments/html-like/comment.js | 💥 | 0.00% |
 | js/comments-closure-typecast/binary-expr.js | 💥 | 0.00% |
@@ -121,7 +119,6 @@ js compatibility: 394/699 (56.37%)
 | js/destructuring/destructuring.js | 💥 | 78.90% |
 | js/destructuring/issue-5988.js | 💥 | 0.00% |
 | js/destructuring-ignore/ignore.js | 💥💥💥 | 77.11% |
-| js/empty-paren-comment/empty_paren_comment.js | 💥 | 94.44% |
 | js/empty-statement/no-newline.js | 💥 | 85.71% |
 | js/explicit-resource-management/for-await-using-of-comments.js | 💥 | 0.00% |
 | js/explicit-resource-management/using-declarations.js | 💥 | 70.00% |
@@ -136,7 +133,7 @@ js compatibility: 394/699 (56.37%)
 | js/for/in.js | 💥 | 50.00% |
 | js/for/parentheses.js | 💥 | 72.00% |
 | js/for-of/async-identifier.js | 💥 | 90.00% |
-| js/function-comments/params-trail-comments.js | 💥 | 82.61% |
+| js/function-comments/params-trail-comments.js | 💥 | 95.83% |
 | js/function-single-destructuring/array.js | 💥 | 35.42% |
 | js/functional-composition/functional_compose.js | 💥 | 93.20% |
 | js/functional-composition/pipe-function-calls-with-comments.js | 💥 | 77.08% |
@@ -147,7 +144,7 @@ js compatibility: 394/699 (56.37%)
 | js/identifier/parentheses/const.js | 💥💥 | 0.00% |
 | js/identifier/parentheses/let.js | 💥💥 | 79.09% |
 | js/if/comment_before_else.js | 💥 | 61.54% |
-| js/if/expr_and_same_line_comments.js | 💥 | 73.33% |
+| js/if/expr_and_same_line_comments.js | 💥 | 86.67% |
 | js/if/if_comments.js | 💥 | 54.72% |
 | js/if/non-block.js | 💥 | 66.67% |
 | js/if/trailing_comment.js | 💥 | 72.73% |
@@ -194,8 +191,6 @@ js compatibility: 394/699 (56.37%)
 | js/method-chain/test.js | 💥 | 54.55% |
 | js/method-chain/this.js | 💥 | 0.00% |
 | js/new-expression/new_expression.js | 💥 | 55.56% |
-| js/newline/backslash_2028.js | 💥 | 50.00% |
-| js/newline/backslash_2029.js | 💥 | 50.00% |
 | js/no-semi/class.js | 💥✨ | 46.55% |
 | js/no-semi/comments.js | 💥✨ | 36.36% |
 | js/no-semi/issue2006.js | 💥✨ | 37.50% |
@@ -258,7 +253,6 @@ js compatibility: 394/699 (56.37%)
 | js/trailing-comma/jsx.js | 💥💥💥 | 0.00% |
 | js/try/catch.js | 💥 | 52.63% |
 | js/try/try.js | 💥 | 50.00% |
-| js/unary-expression/comments.js | 💥 | 76.58% |
 | js/unicode/nbsp-jsx.js | 💥 | 22.22% |
 | js/variable_declarator/multiple.js | 💥 | 87.27% |
 | js/yield/jsx-without-parenthesis.js | 💥 | 50.00% |

tasks/prettier_conformance/snapshots/prettier.ts.snap.md

@@ -76,7 +76,7 @@ ts compatibility: 233/573 (40.66%)
 | typescript/assignment/issue-12413.ts | 💥 | 3.03% |
 | typescript/assignment/issue-2485.ts | 💥 | 44.44% |
 | typescript/call-signature/call-signature.ts | 💥 | 79.66% |
-| typescript/cast/as-const.ts | 💥 | 54.55% |
+| typescript/cast/as-const.ts | 💥 | 60.00% |
 | typescript/cast/generic-cast.ts | 💥 | 39.46% |
 | typescript/cast/tuple-and-record.ts | 💥 | 0.00% |
 | typescript/chain-expression/call-expression.ts | 💥 | 32.81% |
@@ -105,9 +105,9 @@ ts compatibility: 233/573 (40.66%)
 | typescript/comments/jsx.tsx | 💥 | 20.00% |
 | typescript/comments/location.ts | 💥 | 75.00% |
 | typescript/comments/mapped_types.ts | 💥 | 58.82% |
-| typescript/comments/method_types.ts | 💥 | 69.23% |
+| typescript/comments/method_types.ts | 💥 | 74.36% |
 | typescript/comments/methods.ts | 💥 | 97.96% |
-| typescript/comments/type-parameters.ts | 💥 | 39.29% |
+| typescript/comments/type-parameters.ts | 💥 | 40.00% |
 | typescript/comments/type_literals.ts | 💥 | 55.17% |
 | typescript/comments/union.ts | 💥 | 5.26% |
 | typescript/comments-2/dangling.ts | 💥💥 | 75.00% |
@@ -167,12 +167,12 @@ ts compatibility: 233/573 (40.66%)
 | typescript/conformance/types/typeOperator/typeOperator.ts | 💥 | 0.00% |
 | typescript/conformance/types/typeParameter/typeParameter.ts | 💥 | 66.67% |
 | typescript/conformance/types/typeParameters/typeParameterLists/innerTypeParameterShadowingOuterOne2.ts | 💥 | 93.33% |
-| typescript/conformance/types/union/unionTypeCallSignatures.ts | 💥 | 49.51% |
+| typescript/conformance/types/union/unionTypeCallSignatures.ts | 💥 | 61.22% |
 | typescript/conformance/types/union/unionTypeCallSignatures3.ts | 💥 | 68.97% |
 | typescript/conformance/types/union/unionTypeConstructSignatures.ts | 💥 | 61.29% |
 | typescript/conformance/types/union/unionTypeEquivalence.ts | 💥 | 90.00% |
 | typescript/conformance/types/union/unionTypeFromArrayLiteral.ts | 💥 | 93.55% |
-| typescript/conformance/types/union/unionTypeIndexSignature.ts | 💥 | 29.85% |
+| typescript/conformance/types/union/unionTypeIndexSignature.ts | 💥 | 56.67% |
 | typescript/const/initializer-ambient-context.ts | 💥 | 93.33% |
 | typescript/custom/abstract/abstractProperties.ts | 💥 | 75.00% |
 | typescript/custom/computedProperties/string.ts | 💥 | 73.33% |