fix(js_semantic): type value schism (#495)

CHANGELOG.md

@@ -153,6 +153,8 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 
 - Fix [452](https://github.com/biomejs/biome/pull/452). The linter panicked when it met a malformed regex (a regex not ending with a slash).
 
+- Fix [#104](https://github.com/biomejs/biome/issues/104). We now correctly handle types and values with the same name.
+
 ### Parser
 
 - Enhance diagnostic for infer type handling in the parser. The 'infer' keyword can only be utilized within the 'extends' clause of a conditional type. Using it outside of this context will result in an error. Ensure that any type declarations using 'infer' are correctly placed within the conditional type structure to avoid parsing issues. Contributed by @denbezrukov

crates/biome_js_analyze/src/semantic_analyzers/correctness/no_unused_variables.rs

@@ -153,6 +153,9 @@ fn suggested_fix_if_unused(binding: &AnyJsIdentifierBinding) -> Option<Suggested
         | AnyJsBindingDeclaration::JsFunctionExpression(_) => None,
 
         // Some parameters are ok to not be used
+        AnyJsBindingDeclaration::JsArrowFunctionExpression(_) => {
+            suggestion_for_binding(binding)
+        }
         AnyJsBindingDeclaration::TsPropertyParameter(_) => None,
         AnyJsBindingDeclaration::JsFormalParameter(parameter) => {
             if is_function_that_is_ok_parameter_not_be_used(&parameter.parent_function()) {

crates/biome_js_analyze/src/semantic_analyzers/nursery/use_exhaustive_dependencies.rs

@@ -469,7 +469,8 @@ fn capture_needs_to_be_in_the_dependency_list(
         }
 
         // all others need to be in the dependency list
-        AnyJsBindingDeclaration::JsFormalParameter(_)
+        AnyJsBindingDeclaration::JsArrowFunctionExpression(_)
+        | AnyJsBindingDeclaration::JsFormalParameter(_)
         | AnyJsBindingDeclaration::JsRestParameter(_)
         | AnyJsBindingDeclaration::JsBogusParameter(_)
         | AnyJsBindingDeclaration::TsIndexSignatureParameter(_)

crates/biome_js_analyze/src/semantic_analyzers/style/use_naming_convention.rs

@@ -791,7 +791,8 @@ impl Named {
             AnyJsBindingDeclaration::JsVariableDeclarator(var) => {
                 Named::from_variable_declarator(var)
             }
-            AnyJsBindingDeclaration::JsBogusParameter(_)
+            AnyJsBindingDeclaration::JsArrowFunctionExpression(_)
+            | AnyJsBindingDeclaration::JsBogusParameter(_)
             | AnyJsBindingDeclaration::JsFormalParameter(_)
             | AnyJsBindingDeclaration::JsRestParameter(_) => Some(Named::FunctionParameter),
             AnyJsBindingDeclaration::JsCatchDeclaration(_) => Some(Named::CatchParameter),

crates/biome_js_analyze/tests/specs/correctness/noUndeclaredVariables/invalidTypeValueWithSameName.ts

@@ -0,0 +1,2 @@
+const a = 0;
+export type { a }

crates/biome_js_analyze/tests/specs/correctness/noUndeclaredVariables/invalidTypeValueWithSameName.ts.snap

@@ -0,0 +1,24 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: invalidTypeValueWithSameName.ts
+---
+# Input
+```js
+const a = 0;
+export type { a }
+```
+
+# Diagnostics
+```
+invalidTypeValueWithSameName.ts:2:15 lint/correctness/noUndeclaredVariables ━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! The a variable is undeclared
+  
+    1 │ const a = 0;
+  > 2 │ export type { a }
+      │               ^
+  
+
+```
+
+

crates/biome_js_analyze/tests/specs/correctness/noUnusedVariables/invalidTypeValueSameNames.ts

@@ -0,0 +1,10 @@
+
+type a = number
+export const a = 5;
+
+function f() {}
+export type f = () => {}
+
+const b = true
+type b = boolean
+export { type b }

crates/biome_js_analyze/tests/specs/correctness/noUnusedVariables/invalidTypeValueSameNames.ts.snap

@@ -0,0 +1,79 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: invalidTypeValueSameNames.ts
+---
+# Input
+```js
+
+type a = number
+export const a = 5;
+
+function f() {}
+export type f = () => {}
+
+const b = true
+type b = boolean
+export { type b }
+
+```
+
+# Diagnostics
+```
+invalidTypeValueSameNames.ts:2:6 lint/correctness/noUnusedVariables ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! This type alias is unused.
+  
+  > 2 │ type a = number
+      │      ^
+    3 │ export const a = 5;
+    4 │ 
+  
+  i Unused variables usually are result of incomplete refactoring, typos and other source of bugs.
+  
+
+```
+
+```
+invalidTypeValueSameNames.ts:5:10 lint/correctness/noUnusedVariables ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! This function is unused.
+  
+    3 │ export const a = 5;
+    4 │ 
+  > 5 │ function f() {}
+      │          ^
+    6 │ export type f = () => {}
+    7 │ 
+  
+  i Unused variables usually are result of incomplete refactoring, typos and other source of bugs.
+  
+
+```
+
+```
+invalidTypeValueSameNames.ts:8:7 lint/correctness/noUnusedVariables  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━
+
+  ! This variable is unused.
+  
+     6 │ export type f = () => {}
+     7 │ 
+   > 8 │ const b = true
+       │       ^
+     9 │ type b = boolean
+    10 │ export { type b }
+  
+  i Unused variables usually are result of incomplete refactoring, typos and other source of bugs.
+  
+  i Unsafe fix: If this is intentional, prepend b with an underscore.
+  
+     6  6 │   export type f = () => {}
+     7  7 │   
+     8    │ - const·b·=·true
+        8 │ + const·_b·=·true
+     9  9 │   type b = boolean
+    10 10 │   export { type b }
+  
+
+```
+
+

crates/biome_js_analyze/tests/specs/correctness/noUnusedVariables/issue104.ts

@@ -0,0 +1,6 @@
+// See https://github.com/biomejs/biome/issues/104
+
+import { X } from "mod"
+export function f(X: X): X {
+    return X;
+}

crates/biome_js_analyze/tests/specs/correctness/noUnusedVariables/issue104.ts.snap

@@ -0,0 +1,16 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: issue104.ts
+---
+# Input
+```js
+// See https://github.com/biomejs/biome/issues/104
+
+import { X } from "mod"
+export function f(X: X): X {
+    return X;
+}
+
+```
+
+

crates/biome_js_analyze/tests/specs/correctness/noUnusedVariables/validValueExportType.ts

@@ -0,0 +1,5 @@
+class C {}
+enum E {}
+
+export type { C }
+export { type E }

crates/biome_js_analyze/tests/specs/correctness/noUnusedVariables/validValueExportType.ts.snap

@@ -0,0 +1,14 @@
+---
+source: crates/biome_js_analyze/tests/spec_tests.rs
+expression: validValueExportType.ts
+---
+# Input
+```js
+class C {}
+enum E {}
+
+export type { C }
+export { type E }
+```
+
+