fix(formatter): missing parenthesis for expression of decorator

Author: Dunqing

crates/oxc_formatter/src/parentheses/expression.rs

@@ -213,7 +213,7 @@ impl<'a> NeedsParentheses<'a> for AstNode<'a, MemberExpression<'a>> {
 
 impl<'a> NeedsParentheses<'a> for AstNode<'a, ComputedMemberExpression<'a>> {
     fn needs_parentheses(&self, f: &Formatter<'_, 'a>) -> bool {
-        matches!(self.parent, AstNodes::Decorator(_))
+        false
     }
 }
 
@@ -236,26 +236,10 @@ impl<'a> NeedsParentheses<'a> for AstNode<'a, PrivateFieldExpression<'a>> {
     }
 }
 
-fn is_identifier_or_static_member_only(callee: &Expression) -> bool {
-    let mut expr = callee;
-    loop {
-        match expr {
-            Expression::Identifier(_) => return true,
-            Expression::StaticMemberExpression(static_member) => {
-                expr = &static_member.object;
-            }
-            _ => break,
-        }
-    }
-
-    false
-}
-
 impl<'a> NeedsParentheses<'a> for AstNode<'a, CallExpression<'a>> {
     fn needs_parentheses(&self, f: &Formatter<'_, 'a>) -> bool {
         match self.parent {
             AstNodes::NewExpression(_) => true,
-            AstNodes::Decorator(_) => !is_identifier_or_static_member_only(&self.callee),
             AstNodes::ExportDefaultDeclaration(_) => {
                 let callee = &self.callee();
                 let callee_span = callee.span();
@@ -535,7 +519,7 @@ impl<'a> NeedsParentheses<'a> for AstNode<'a, AwaitExpression<'a>> {
 impl<'a> NeedsParentheses<'a> for AstNode<'a, ChainExpression<'a>> {
     fn needs_parentheses(&self, f: &Formatter<'_, 'a>) -> bool {
         match self.parent {
-            AstNodes::NewExpression(_) | AstNodes::Decorator(_) => true,
+            AstNodes::NewExpression(_) => true,
             AstNodes::CallExpression(call) => !call.optional,
             AstNodes::StaticMemberExpression(member) => !member.optional,
             AstNodes::ComputedMemberExpression(member) => {

crates/oxc_formatter/src/write/decorators.rs

@@ -50,10 +50,48 @@ impl<'a> Format<'a> for AstNode<'a, Vec<'a, Decorator<'a>>> {
     }
 }
 
+fn is_identifier_or_static_member_only(callee: &Expression) -> bool {
+    let mut expr = callee;
+    loop {
+        match expr {
+            Expression::Identifier(_) => return true,
+            Expression::StaticMemberExpression(static_member) => {
+                expr = &static_member.object;
+            }
+            _ => break,
+        }
+    }
+
+    false
+}
+
 impl<'a> FormatWrite<'a> for AstNode<'a, Decorator<'a>> {
     fn write(&self, f: &mut Formatter<'_, 'a>) -> FormatResult<()> {
         self.format_leading_comments(f)?;
-        write!(f, ["@", self.expression()])
+        write!(f, ["@"]);
+
+        // Determine if parentheses are required around decorator expressions
+        let needs_parentheses = match &self.expression {
+            // Identifiers: `@decorator` needs no parens
+            Expression::Identifier(_) => false,
+            // Call expressions: `@obj.method()` needs no parens, `@(complex().method)()` needs parens
+            Expression::CallExpression(call) => !is_identifier_or_static_member_only(&call.callee),
+            // Static member expressions: `@obj.prop` needs no parens, `@(complex[key])` needs parens
+            Expression::StaticMemberExpression(static_member) => {
+                !is_identifier_or_static_member_only(&static_member.object)
+            }
+            // All other expressions need parentheses: `@(a + b)`, `@(condition ? a : b)`
+            _ => true,
+        };
+
+        if needs_parentheses {
+            write!(f, "(")?;
+        }
+        write!(f, [self.expression()])?;
+        if needs_parentheses {
+            write!(f, ")")?;
+        }
+        Ok(())
     }
 }
 

tasks/coverage/snapshots/formatter_typescript.snap

@@ -2,7 +2,7 @@ commit: 261630d6
 
 formatter_typescript Summary:
 AST Parsed     : 8816/8816 (100.00%)
-Positive Passed: 8755/8816 (99.31%)
+Positive Passed: 8763/8816 (99.40%)
 Expect to Parse: tasks/coverage/typescript/tests/cases/compiler/APISample_jsdoc.ts
 Expected `]` but found `:`
 Mismatch: tasks/coverage/typescript/tests/cases/compiler/amdLikeInputDeclarationEmit.ts
@@ -65,20 +65,10 @@ Mismatch: tasks/coverage/typescript/tests/cases/compiler/unionSignaturesWithThis
 
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/classes/propertyMemberDeclarations/overrideInterfaceProperty.ts
 'readonly' type modifier is only permitted on array and tuple literal types.
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/classes/propertyMemberDeclarations/staticAutoAccessorsWithDecorators.ts
-Unexpected token
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/classes/propertyMemberDeclarations/staticPropertyNameConflicts.ts
 Classes may not have a static property named prototypeClasses may not have a static property named prototypeClasses may not have a static property named prototypeClasses may not have a static property named prototypeClasses may not have a static property named prototypeClasses may not have a static property named prototype
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/controlFlow/controlFlowAssignmentPatternOrder.ts
 An implementation cannot be declared in ambient contexts.
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/decorators/class/decoratorChecksFunctionBodies.ts
-Unexpected token
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/decorators/legacyDecorators-contextualTypes.ts
-Unexpected token
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts
-Cannot use `yield` as an identifier in a generator context
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck61.ts
-Cannot use `yield` as an identifier in a generator contextUnexpected token
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/esDecorators/classDeclaration/classSuper/esDecorators-classDeclaration-classSuper.2.ts
 Expected `{` but found `as`
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/esDecorators/classExpression/classSuper/esDecorators-classExpression-classSuper.2.ts
@@ -87,10 +77,6 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/esDecorators/
 Decorators are not valid here.Unexpected token
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/esDecorators/classExpression/namedEvaluation/esDecorators-classExpression-namedEvaluation.8.ts
 Decorators are not valid here.Unexpected token
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/esDecorators/esDecorators-contextualTypes.ts
-Unexpected token
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/esDecorators/esDecorators-decoratorExpression.2.ts
-Unexpected token
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/expressions/asOperator/asOpEmitParens.ts
 Expected a semicolon or an implicit semicolon after a statement, but found none
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/expressions/elementAccess/letIdentifierInElementAccess01.ts
@@ -101,8 +87,6 @@ Mismatch: tasks/coverage/typescript/tests/cases/conformance/expressions/typeGuar
 
 Mismatch: tasks/coverage/typescript/tests/cases/conformance/expressions/typeGuards/typeGuardsInRightOperandOfOrOrOperator.ts
 
-Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/externalModules/topLevelAwait.1.ts
-Cannot use `await` as an identifier in an async contextUnexpected token
 Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/generators/yieldStatementNoAsiAfterTransform.ts
 Expected a semicolon or an implicit semicolon after a statement, but found none
 Mismatch: tasks/coverage/typescript/tests/cases/conformance/interfaces/interfacesExtendingClasses/interfaceExtendingClassWithPrivates2.ts

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

@@ -115,7 +115,6 @@ ts compatibility: 351/573 (61.26%)
 | typescript/declare/object-type-in-declare-function.ts | 💥 | 58.82% |
 | typescript/declare/trailing-comma/function-rest-trailing-comma.ts | 💥💥💥 | 50.00% |
 | typescript/decorators/comments.ts | 💥 | 60.00% |
-| typescript/decorators/decorator-type-assertion.ts | 💥 | 60.00% |
 | typescript/decorators/decorators-comments.ts | 💥 | 65.71% |
 | typescript/decorators-ts/angular.ts | 💥 | 87.50% |
 | typescript/decorators-ts/typeorm.ts | 💥 | 88.37% |