fix: Date 多参构造年 0-99 按规范映射到 1900-1999

crates/oxide_builtins/src/date.rs

@@ -179,6 +179,12 @@ pub fn date_constructor<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
         Utc::now().timestamp_millis() as f64
     } else if args.len() > 2 {
         let y_val = oxide_runtime_api::to_number(vm.reg(args[1]));
+        // 年 0..99 按规范映射到 1900..1999（ToInteger 截断后判断）。
+        let y_val = if (0.0..=99.0).contains(&y_val.trunc()) {
+            y_val.trunc() + 1900.0
+        } else {
+            y_val
+        };
         let m_val = oxide_runtime_api::to_number(vm.reg(args[2]));
         let d_val = if args.len() > 3 { oxide_runtime_api::to_number(vm.reg(args[3])) } else { 1.0 };
         let h_val = if args.len() > 4 { oxide_runtime_api::to_number(vm.reg(args[4])) } else { 0.0 };

crates/oxide_vm/tests/builtins_date_tests.rs

@@ -326,6 +326,18 @@ fn date_constructor_truncation() {
     assert_eq!(r.as_double(), 5.0);
 }
 
+#[test]
+fn date_constructor_two_digit_year_maps_to_1900s() {
+    let mut vm = Vm::new();
+    // 多参构造年 0..99 按规范映射到 1900..1999；100 起不再调整。
+    let r = eval(&mut vm, "new Date(0, 0).getFullYear()").unwrap();
+    assert_eq!(r.as_double(), 1900.0);
+    let r = eval(&mut vm, "new Date(99, 0).getFullYear()").unwrap();
+    assert_eq!(r.as_double(), 1999.0);
+    let r = eval(&mut vm, "new Date(100, 0).getFullYear()").unwrap();
+    assert_eq!(r.as_double(), 100.0);
+}
+
 #[test]
 fn date_setters_return_timestamp() {
     let mut vm = Vm::new();