fix(js_semantic): add semantic scope to mapped types (biomejs#958)

CHANGELOG.md

@@ -50,6 +50,8 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 
 - Fix [#918](https://github.com/biomejs/biome/issues/918), [useSimpleNumberKeys](https://biomejs.dev/linter/rules/use-simple-number-keys) no longer repports false positive on comments. Contributed by @kalleep
 
+- Fix [#953](https://github.com/biomejs/biome/issues/953), [noRedeclare](https://biomejs.dev/linter/rules/no-redeclare) no longer reports type parameters with the same name in different mapped types as redeclarations. Contributed by @Conaclos
+
 ### Parser
 
 ## 1.4.0 (2023-11-27)

crates/biome_js_analyze/tests/specs/suspicious/noRedeclare/valid-mapped-types.ts

@@ -0,0 +1,9 @@
+// See https://github.com/biomejs/biome/issues/953
+type X = never;
+type Y = never;
+export const MyMappingPbToGql: {
+    [key in X]: never;
+} = {};
+export const MyOtherMappingPbToGql: {
+    [key in Y]: never;
+} = {};

crates/biome_js_analyze/tests/specs/suspicious/noRedeclare/valid-mapped-types.ts.snap

@@ -0,0 +1,19 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: valid-mapped-types.ts
+---
+# Input
+```js
+// See https://github.com/biomejs/biome/issues/953
+type X = never;
+type Y = never;
+export const MyMappingPbToGql: {
+    [key in X]: never;
+} = {};
+export const MyOtherMappingPbToGql: {
+    [key in Y]: never;
+} = {};
+
+```
+
+

crates/biome_js_semantic/src/events.rs

@@ -279,6 +279,7 @@ impl SemanticEventExtractor {
     /// See [SemanticEvent] for a more detailed description of which events [SyntaxNode] generates.
     #[inline]
     pub fn enter(&mut self, node: &JsSyntaxNode) {
+        // If you push a scope for a given node type, don't forget to also update `Self::leave`.
         match node.kind() {
             JS_IDENTIFIER_BINDING | TS_IDENTIFIER_BINDING | TS_TYPE_PARAMETER_NAME => {
                 self.enter_identifier_binding(&AnyJsIdentifierBinding::unwrap_cast(node.clone()));
@@ -355,9 +356,15 @@ impl SemanticEventExtractor {
     fn enter_any_type(&mut self, node: &AnyTsType) {
         if node.in_conditional_true_type() {
             self.push_conditional_true_scope(node);
-        } else if let Some(node) = node.as_ts_function_type() {
+            return;
+        }
+        let node = node.syntax();
+        if matches!(
+            node.kind(),
+            JsSyntaxKind::TS_FUNCTION_TYPE | JsSyntaxKind::TS_MAPPED_TYPE
+        ) {
             self.push_scope(
-                node.syntax().text_range(),
+                node.text_range(),
                 ScopeHoisting::DontHoistDeclarationsToParent,
                 false,
             );
@@ -589,8 +596,9 @@ impl SemanticEventExtractor {
     #[inline]
     pub fn leave(&mut self, node: &JsSyntaxNode) {
         match node.kind() {
-            JS_MODULE | JS_SCRIPT => self.pop_scope(node.text_range()),
-            JS_FUNCTION_DECLARATION
+            JS_MODULE
+            | JS_SCRIPT
+            | JS_FUNCTION_DECLARATION
             | JS_FUNCTION_EXPORT_DEFAULT_DECLARATION
             | JS_FUNCTION_EXPRESSION
             | JS_ARROW_FUNCTION_EXPRESSION
@@ -636,8 +644,14 @@ impl SemanticEventExtractor {
     fn leave_any_type(&mut self, node: &AnyTsType) {
         if node.in_conditional_true_type() {
             self.pop_scope(node.syntax().text_range());
-        } else if let Some(node) = node.as_ts_function_type() {
-            self.pop_scope(node.syntax().text_range());
+            return;
+        }
+        let node = node.syntax();
+        if matches!(
+            node.kind(),
+            JsSyntaxKind::TS_FUNCTION_TYPE | JsSyntaxKind::TS_MAPPED_TYPE
+        ) {
+            self.pop_scope(node.text_range());
         }
     }
 
@@ -922,6 +936,8 @@ impl Iterator for SemanticEventIterator {
                         if let Some(e) = self.extractor.pop() {
                             break Some(e);
                         } else {
+                            // Check that every scope was pop.
+                            debug_assert!(self.extractor.scopes.is_empty());
                             break None;
                         }
                     }

website/src/content/docs/internals/changelog.mdx

@@ -56,6 +56,8 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 
 - Fix [#918](https://github.com/biomejs/biome/issues/918), [useSimpleNumberKeys](https://biomejs.dev/linter/rules/use-simple-number-keys) no longer repports false positive on comments. Contributed by @kalleep
 
+- Fix [#953](https://github.com/biomejs/biome/issues/953), [noRedeclare](https://biomejs.dev/linter/rules/no-redeclare) no longer reports type parameters with the same name in different mapped types as redeclarations. Contributed by @Conaclos
+
 ### Parser
 
 ## 1.4.0 (2023-11-27)