fix(formatter): break parens of (a + b)[c] like (a + b).c (#28199)

```js
// before
(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb)[c];

// after
(
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
)[c];
```

crates/oxc_formatter/DIVERGENCES.md

@@ -1167,3 +1167,36 @@ x =
 
 An own-line comment before a member's `.` stays before it, for `.b` and `.#b` alike.
 Prettier moves it before the object for `.b`, and after the `.` for `.#b`; both cross a token.
+
+## computed-member-object-paren-break
+
+- Why: uniform-rule (same construct, same output: `(a + b).c` and `(await a)[c]`)
+- Pin: `tests/fixtures/js/parenthesis/computed-member-object-paren-break.js`
+- Conformance: `js/ternaries/indent-after-paren.js`
+
+```js
+// input (printWidth: 80)
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb)[c];
+(someCondition ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee : someVeryLongAlternateValueeeeeeeeeee)[c];
+
+// ours: the same as `.c`
+(
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+)[c];
+(someCondition
+  ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee
+  : someVeryLongAlternateValueeeeeeeeeee
+)[c];
+
+// prettier
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb)[c];
+(someCondition
+  ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee
+  : someVeryLongAlternateValueeeeeeeeeee)[c];
+```
+
+A binary-like or conditional object of a member breaks its parens the same way for `.c`, `[c]` and `?.[c]`.
+Prettier does so for `.c` only, while an `await` / `as` object breaks them for `[c]` too.
+The computed property (`a[b + c]`) keeps its own layout.

crates/oxc_formatter/src/ast_nodes/impls/ast_nodes.rs

@@ -66,11 +66,6 @@ impl<'parent, 'a> AstNodes<'parent, 'a> {
         )
     }
 
-    /// Check if this is a non-computed member expression: `a.b` or `a.#b`
-    pub fn is_non_computed_member_expression(&self) -> bool {
-        matches!(self, AstNodes::StaticMemberExpression(_) | AstNodes::PrivateFieldExpression(_))
-    }
-
     /// Check if this is a binary-like expression: `a || b`, `a + b`, or `#x in b`
     pub fn is_binary_like(&self) -> bool {
         matches!(

crates/oxc_formatter/src/print/binary_like_expression.rs

@@ -224,7 +224,7 @@ impl<'a> Format<'a, JsFormatContext<'a>> for BinaryLikeExpression<'a, '_> {
         }
 
         // Add a group with a soft block indent in cases where it is necessary to parenthesize the binary expression.
-        // For example, `(a+b)(call)`, `!(a + b)`, `(a + b).test`.
+        // For example, `(a+b)(call)`, `!(a + b)`, `(a + b).test`, `(a + b)[test]`.
         let is_inside_parenthesis = match parent {
             // The unary's own comment parens already provide the group and indent
             AstNodes::UnaryExpression(unary) if unary_argument_takes_comment_parens(unary, f) => {
@@ -232,7 +232,7 @@ impl<'a> Format<'a, JsFormatContext<'a>> for BinaryLikeExpression<'a, '_> {
             }
             AstNodes::UnaryExpression(_) => true,
             _ => {
-                parent.is_non_computed_member_expression()
+                parent.is_member_object_span(self.span())
                     || parent.is_call_like_callee_span(self.span())
             }
         };

crates/oxc_formatter/src/utils/conditional.rs

@@ -36,11 +36,6 @@ impl<'a> ConditionalLike<'a, '_> {
             ConditionalLike::TSConditionalType(ty) => ty.parent(),
         }
     }
-
-    #[inline]
-    fn is_conditional_expression(&self) -> bool {
-        matches!(self, ConditionalLike::ConditionalExpression(_))
-    }
 }
 
 /// Layout information for a conditional expression to determine formatting strategy
@@ -339,14 +334,6 @@ impl<'a> FormatConditionalLike<'a, '_> {
         }
     }
 
-    /// Returns `true` if this is the root conditional expression and the parent is a non-computed member: `.b` or `.#b`
-    #[inline]
-    fn is_parent_static_member_expression(&self, layout: ConditionalLayout) -> bool {
-        layout.is_root()
-            && self.is_conditional_expression()
-            && self.parent().is_non_computed_member_expression()
-    }
-
     /// Formats the test part of the conditional
     fn format_test<'f>(&self, f: &mut JsFormatter<'f, 'a>, layout: ConditionalLayout) {
         let format_inner = format_with(|f| {
@@ -550,16 +537,16 @@ impl<'a> Format<'a, JsFormatContext<'a>> for FormatConditionalLike<'a, '_> {
 
             format_tail_with_indent.fmt(f);
 
-            // Add a soft line break in front of the closing `)` in case the parent is a static member expression
+            // Add a soft line break in front of the closing `)` in case it is the object of a member expression
             // ```text
             // (veryLongCondition
             //      ? a
             //      : b // <- enforce line break here if the conditional breaks
-            // ).more
+            // ).more // or `)[more]`
             // ```
             if !should_extra_indent
                 && !is_jsx_chain
-                && self.is_parent_static_member_expression(layout)
+                && self.parent().is_member_object_span(self.span())
             {
                 write!(f, [soft_line_break()]);
             }

crates/oxc_formatter/tests/fixtures/js/parenthesis/computed-member-object-paren-break.js

@@ -0,0 +1,9 @@
+// DIVERGENCES.md#computed-member-object-paren-break
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb).c;
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb)[c];
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa || bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb)?.[c];
+(someCondition ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee : someVeryLongAlternateValueeeeeeeeeee).c;
+(someCondition ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee : someVeryLongAlternateValueeeeeeeeeee)[c];
+
+// The property keeps its own layout
+xxxxxxxxxx[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb];

crates/oxc_formatter/tests/fixtures/js/parenthesis/computed-member-object-paren-break.js.snap

@@ -0,0 +1,78 @@
+---
+source: crates/oxc_formatter/tests/fixtures/mod.rs
+---
+==================== Input ====================
+// DIVERGENCES.md#computed-member-object-paren-break
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb).c;
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb)[c];
+(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa || bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb)?.[c];
+(someCondition ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee : someVeryLongAlternateValueeeeeeeeeee).c;
+(someCondition ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee : someVeryLongAlternateValueeeeeeeeeee)[c];
+
+// The property keeps its own layout
+xxxxxxxxxx[aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb];
+
+==================== Output ====================
+------------------
+{ printWidth: 80 }
+------------------
+// DIVERGENCES.md#computed-member-object-paren-break
+(
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+).c;
+(
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+)[c];
+(
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ||
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+)?.[c];
+(someCondition
+  ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee
+  : someVeryLongAlternateValueeeeeeeeeee
+).c;
+(someCondition
+  ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee
+  : someVeryLongAlternateValueeeeeeeeeee
+)[c];
+
+// The property keeps its own layout
+xxxxxxxxxx[
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+    bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+];
+
+-------------------
+{ printWidth: 100 }
+-------------------
+// DIVERGENCES.md#computed-member-object-paren-break
+(
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+).c;
+(
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+)[c];
+(
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa ||
+  bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+)?.[c];
+(someCondition
+  ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee
+  : someVeryLongAlternateValueeeeeeeeeee
+).c;
+(someCondition
+  ? someVeryLongConsequentValueeeeeeeeeeeeeeeeeeee
+  : someVeryLongAlternateValueeeeeeeeeee
+)[c];
+
+// The property keeps its own layout
+xxxxxxxxxx[
+  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
+    bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+];
+
+===================== End =====================

crates/oxc_formatter/tests/snapshots/conformance__prettier-js.snap

@@ -2,7 +2,7 @@
 source: crates/oxc_formatter/tests/conformance.rs
 expression: report
 ---
-js compatibility: 1033/1123 (91.99%), 23 files skipped
+js compatibility: 1029/1123 (91.63%), 23 files skipped
 
 # Failed
 
@@ -55,6 +55,7 @@ js compatibility: 1033/1123 (91.99%), 23 files skipped
 | js/switch/comments.js | 💥 | 94.74% |
 | js/template-literals/expression-break.js | 💥 | 80.00% |
 | js/template-literals/expressions.js | 💥 | 97.64% |
+| js/ternaries/indent-after-paren.js | 💥💥💥💥 | 99.14% |
 | js/test-declarations/jest-each.js | 💥💥 | 95.71% |
 | js/trailing-comma/trailing_whitespace.js | 💥💥💥 | 96.55% |
 | js/try/try.js | 💥 | 44.44% |

tasks/track_memory_allocations/allocs_formatter.yaml

@@ -44,9 +44,9 @@ pdf.mjs:
 
 antd.js:
   file size: 6686316 # 6.69 MB
-  sys allocs: 74785
+  sys allocs: 74784
   sys reallocs: 351
-  sys deallocs: 74784
+  sys deallocs: 74783
   sys alloc bytes: 23137418 # 23.14 MB
   sys peak growth: 13710144 # 13.71 MB
   arena allocs: 120676