feat: 支持可选链空值合并与逻辑赋值

crates/oxide_vm/tests/logical_tests.rs

@@ -78,3 +78,76 @@ fn eval_and_chain() {
 fn eval_or_chain() {
     assert_eq!(eval("0 || false || 42"), "42");
 }
+
+#[test]
+fn eval_nullish_coalescing() {
+    assert_eq!(eval("null ?? 5"), "5");
+    assert_eq!(eval("undefined ?? 'x'"), "{string}");
+    assert_eq!(eval("0 ?? 5"), "0");
+    assert_eq!(eval("false ?? 5"), "false");
+}
+
+#[test]
+fn eval_nullish_coalescing_short_circuits_rhs() {
+    assert_eq!(eval("var x = 0; 1 ?? (x = 5); x"), "0");
+}
+
+#[test]
+fn eval_optional_member_chain() {
+    assert_eq!(eval("var a={b:{c:7}}; a?.b?.c"), "7");
+    assert_eq!(eval("var a=null; a?.b"), "undefined");
+    assert_eq!(eval("var a={b:1}; a?.b"), "1");
+    assert_eq!(eval("var a=null; a?.b.c.d"), "undefined");
+}
+
+#[test]
+fn eval_optional_computed_chain() {
+    assert_eq!(eval("var o={k:'b'}, a={b:9}; a?.[o.k]"), "9");
+    assert_eq!(eval("var o={k:'b'}, a=null; a?.[o.k]"), "undefined");
+}
+
+#[test]
+fn eval_optional_parenthesized_reset() {
+    assert_eq!(eval("var a=null; (a?.b)"), "undefined");
+    assert!(eval("var a=null; (a?.b).c").contains("TypeError"));
+}
+
+#[test]
+fn eval_optional_call() {
+    assert_eq!(eval("var a={b:function(){return this.n},n:5}; a?.b()"), "5");
+    assert_eq!(eval("var a=null; a?.b()"), "undefined");
+    assert!(eval("var a={b:5}; a?.b()").contains("TypeError"));
+}
+
+#[test]
+fn eval_delete_optional_chain() {
+    assert_eq!(eval("var a=null; delete a?.b"), "true");
+    assert_eq!(eval("var a={b:1}; delete a?.b; a.b"), "undefined");
+}
+
+#[test]
+fn eval_logical_assignment_vars() {
+    assert_eq!(eval("var a=0; a ||= 5; a"), "5");
+    assert_eq!(eval("var a=1; a ||= 5; a"), "1");
+    assert_eq!(eval("var a=1; a &&= 9; a"), "9");
+    assert_eq!(eval("var a=0; a &&= 9; a"), "0");
+    assert_eq!(eval("var a=null; a ??= 7; a"), "7");
+    assert_eq!(eval("var a=0; a ??= 7; a"), "0");
+}
+
+#[test]
+fn eval_logical_assignment_rhs_short_circuits() {
+    assert_eq!(eval("var a=1; var x=0; a ||= (x=5); x"), "0");
+    assert_eq!(eval("var a=0; var x=0; a &&= (x=5); x"), "0");
+    assert_eq!(eval("var a=0; var x=0; a ??= (x=5); x"), "0");
+}
+
+#[test]
+fn eval_logical_assignment_members() {
+    assert_eq!(eval("var o={x:0}; o.x ||= 5; o.x"), "5");
+    assert_eq!(eval("var o={x:1}; o.x ||= 5; o.x"), "1");
+    assert_eq!(eval("var o={x:1}; o.x &&= 9; o.x"), "9");
+    assert_eq!(eval("var o={x:0}; o.x &&= 9; o.x"), "0");
+    assert_eq!(eval("var o={x:null}; o.x ??= 7; o.x"), "7");
+    assert_eq!(eval("var o={x:0}; o.x ??= 7; o.x"), "0");
+}