fix(isolated-declarations): false positive for setter method in interface

crates/oxc_isolated_declarations/src/declaration.rs

@@ -1,12 +1,16 @@
 use std::cell::Cell;
 
 use oxc_allocator::Box;
+use oxc_allocator::CloneIn;
+use oxc_allocator::Vec;
 #[allow(clippy::wildcard_imports)]
 use oxc_ast::ast::*;
-use oxc_ast::{syntax_directed_operations::BoundNames, Visit};
+use oxc_ast::visit::walk_mut::walk_ts_signatures;
+use oxc_ast::{syntax_directed_operations::BoundNames, Visit, VisitMut};
 use oxc_span::{GetSpan, SPAN};
 use oxc_syntax::scope::ScopeFlags;
 
+use crate::diagnostics::accessor_must_have_explicit_return_type;
 use crate::{
     diagnostics::{
         binding_element_export, inferred_type_of_expression, signature_computed_property_name,
@@ -217,19 +221,19 @@ impl<'a> IsolatedDeclarations<'a> {
                 }
             }
             Declaration::TSTypeAliasDeclaration(alias_decl) => {
-                self.visit_ts_type_alias_declaration(alias_decl);
                 if !check_binding || self.scope.has_reference(&alias_decl.id.name) {
-                    // SAFETY: `ast.copy` is unsound! We need to fix.
-                    Some(unsafe { self.ast.copy(decl) })
+                    let mut decl = decl.clone_in(self.ast.allocator);
+                    self.visit_declaration(&mut decl);
+                    Some(decl)
                 } else {
                     None
                 }
             }
             Declaration::TSInterfaceDeclaration(interface_decl) => {
-                self.visit_ts_interface_declaration(interface_decl);
                 if !check_binding || self.scope.has_reference(&interface_decl.id.name) {
-                    // SAFETY: `ast.copy` is unsound! We need to fix.
-                    Some(unsafe { self.ast.copy(decl) })
+                    let mut decl = decl.clone_in(self.ast.allocator);
+                    self.visit_declaration(&mut decl);
+                    Some(decl)
                 } else {
                     None
                 }
@@ -286,15 +290,30 @@ impl<'a> IsolatedDeclarations<'a> {
     }
 }
 
-impl<'a> Visit<'a> for IsolatedDeclarations<'a> {
-    fn visit_ts_method_signature(&mut self, signature: &TSMethodSignature<'a>) {
+impl<'a> VisitMut<'a> for IsolatedDeclarations<'a> {
+    fn visit_ts_signatures(&mut self, signatures: &mut Vec<'a, TSSignature<'a>>) {
+        self.transform_ts_signatures(signatures);
+        walk_ts_signatures(self, signatures);
+    }
+
+    fn visit_ts_method_signature(&mut self, signature: &mut TSMethodSignature<'a>) {
+        self.report_signature_property_key(&signature.key, signature.computed);
         if signature.return_type.is_none() {
-            self.error(inferred_type_of_expression(signature.span));
+            match signature.kind {
+                TSMethodSignatureKind::Method => {
+                    self.error(inferred_type_of_expression(signature.span));
+                }
+                TSMethodSignatureKind::Get => {
+                    self.error(accessor_must_have_explicit_return_type(signature.key.span()));
+                }
+                TSMethodSignatureKind::Set => {
+                    // setter method don't need return type
+                }
+            }
         }
-        self.report_signature_property_key(&signature.key, signature.computed);
     }
 
-    fn visit_ts_property_signature(&mut self, signature: &TSPropertySignature<'a>) {
+    fn visit_ts_property_signature(&mut self, signature: &mut TSPropertySignature<'a>) {
         self.report_signature_property_key(&signature.key, signature.computed);
     }
 }

crates/oxc_isolated_declarations/src/lib.rs

@@ -16,6 +16,7 @@ mod literal;
 mod module;
 mod return_type;
 mod scope;
+mod signatures;
 mod types;
 
 use std::{cell::RefCell, collections::VecDeque, mem};

crates/oxc_isolated_declarations/src/signatures.rs

@@ -0,0 +1,52 @@
+use oxc_allocator::{CloneIn, Vec};
+use oxc_ast::ast::{TSMethodSignatureKind, TSSignature};
+use rustc_hash::FxHashMap;
+
+use crate::IsolatedDeclarations;
+
+impl<'a> IsolatedDeclarations<'a> {
+    /// Transform setter signature or getter return type to match the other
+    ///
+    /// Infer get accessor return type from set accessor's param type
+    /// Infer set accessor parameter type from get accessor return type
+    pub fn transform_ts_signatures(&mut self, signatures: &mut Vec<'a, TSSignature<'a>>) {
+        // <name, (requires_inference, first_param_annotation, return_type)>
+        let mut method_annotations: FxHashMap<_, (bool, _, _)> = FxHashMap::default();
+
+        signatures.iter_mut().for_each(|signature| {
+            if let TSSignature::TSMethodSignature(method) = signature {
+                let Some(name) = method.key.static_name() else {
+                    return;
+                };
+                match method.kind {
+                    TSMethodSignatureKind::Method => {}
+                    TSMethodSignatureKind::Set => {
+                        let Some(first_param) = method.params.items.first_mut() else {
+                            return;
+                        };
+
+                        let entry = method_annotations.entry(name).or_default();
+                        entry.0 |= first_param.pattern.type_annotation.is_some();
+                        entry.1 = Some(&mut first_param.pattern.type_annotation);
+                    }
+                    TSMethodSignatureKind::Get => {
+                        let entry = method_annotations.entry(name).or_default();
+                        entry.0 |= method.return_type.is_some();
+                        entry.2 = Some(&mut method.return_type);
+                    }
+                };
+            }
+        });
+
+        for (requires_inference, param, return_type) in method_annotations.into_values() {
+            if !requires_inference {
+                return;
+            }
+            if let (Some(Some(annotation)), Some(option)) | (Some(option), Some(Some(annotation))) =
+                (param, return_type)
+            {
+                option.replace(annotation.clone_in(self.ast.allocator));
+            }
+        }
+    }
+}

crates/oxc_isolated_declarations/tests/fixtures/signatures.ts

@@ -0,0 +1,13 @@
+export interface X {
+  set value(_: string);
+}
+
+export type A = {
+  set value({ a, b, c }: { a: string; b: string; c: string });
+  get value();
+};
+
+export interface I {
+  set value(_);
+  get value(): string;
+}

crates/oxc_isolated_declarations/tests/snapshots/signatures.snap

@@ -0,0 +1,25 @@
+---
+source: crates/oxc_isolated_declarations/tests/mod.rs
+input_file: crates/oxc_isolated_declarations/tests/fixtures/signatures.ts
+---
+==================== .D.TS ====================
+
+export interface X {
+	set value(_: string);
+}
+export type A = {
+	set value({ a, b, c }: {
+		a: string;
+		b: string;
+		c: string;
+	});
+	get value(): {
+		a: string;
+		b: string;
+		c: string;
+	};
+};
+export interface I {
+	set value(_: string);
+	get value(): string;
+}