fix(parser): fix conditional expressions with arrow-function alternates in TS (#20356)

fixes https://github.com/rolldown/rolldown/issues/8676

crates/oxc_parser/src/js/arrow.rs

@@ -22,7 +22,7 @@ impl<'a, C: Config> ParserImpl<'a, C> {
         match self.is_parenthesized_arrow_function_expression() {
             Tristate::False => None,
             Tristate::True => Some(self.parse_parenthesized_arrow_function_expression(
-                /* allow_return_type_in_arrow_function */ true,
+                allow_return_type_in_arrow_function,
             )),
             Tristate::Maybe => self.parse_possible_parenthesized_arrow_function_expression(
                 allow_return_type_in_arrow_function,

tasks/coverage/misc/pass/conditional-arrow-alternate-return-type.ts

@@ -0,0 +1,16 @@
+const formErrors = { foo: 'bar' };
+
+type Form = { id: number; errors: Record<string, boolean> };
+
+type Errors<T extends Form> = Pick<T, 'errors'>;
+
+type FooBarForm = Form & { tag: 'foobarform' };
+
+const getFormError =
+  typeof formErrors !== 'object'
+    ? () => ({})
+    : (index: number): Errors<FooBarForm> => {
+        return {
+          errors: { a: true, b: false },
+        };
+      };

tasks/coverage/snapshots/codegen_misc.snap

@@ -1,3 +1,3 @@
 codegen_misc Summary:
-AST Parsed     : 64/64 (100.00%)
-Positive Passed: 64/64 (100.00%)
+AST Parsed     : 65/65 (100.00%)
+Positive Passed: 65/65 (100.00%)

tasks/coverage/snapshots/formatter_misc.snap

@@ -1,3 +1,3 @@
 formatter_misc Summary:
-AST Parsed     : 64/64 (100.00%)
-Positive Passed: 64/64 (100.00%)
+AST Parsed     : 65/65 (100.00%)
+Positive Passed: 65/65 (100.00%)

tasks/coverage/snapshots/parser_misc.snap

@@ -1,6 +1,6 @@
 parser_misc Summary:
-AST Parsed     : 64/64 (100.00%)
-Positive Passed: 64/64 (100.00%)
+AST Parsed     : 65/65 (100.00%)
+Positive Passed: 65/65 (100.00%)
 Negative Passed: 134/134 (100.00%)
 
   × Cannot assign to 'arguments' in strict mode

tasks/coverage/snapshots/semantic_misc.snap

@@ -1,6 +1,11 @@
 semantic_misc Summary:
-AST Parsed     : 64/64 (100.00%)
-Positive Passed: 51/64 (79.69%)
+AST Parsed     : 65/65 (100.00%)
+Positive Passed: 51/65 (78.46%)
+semantic Error: tasks/coverage/misc/pass/conditional-arrow-alternate-return-type.ts
+Unresolved references mismatch:
+after transform: ["Pick", "Record"]
+rebuilt        : []
+
 semantic Error: tasks/coverage/misc/pass/declare-let-private.ts
 Bindings mismatch:
 after transform: ScopeId(0): ["private"]

tasks/coverage/snapshots/transformer_misc.snap

@@ -1,3 +1,3 @@
 transformer_misc Summary:
-AST Parsed     : 64/64 (100.00%)
-Positive Passed: 64/64 (100.00%)
+AST Parsed     : 65/65 (100.00%)
+Positive Passed: 65/65 (100.00%)