更新：添加doString方法及对应的单元测试

src/lua_runner_test.cj

@@ -1,4 +1,4 @@
-package luarunner
+package luaRunner
 
 import std.unittest.*  // cjlint-ignore G.PKG.01
 import std.fs.*  // cjlint-ignore G.PKG.01
@@ -254,7 +254,58 @@ func testRedirectIoRead(): Unit {
 }
 
 // ====================
-// 6. 错误码与回调
+// 6. doString 测试
+// ====================
+
+@Test
+func testDoStringSimple(): Unit {
+    let runner = LuaRunner()
+    let res = runner.doString("return 1 + 1")
+    @Expect(res, "2")
+}
+
+@Test
+func testDoStringWithGlobal(): Unit {
+    let runner = LuaRunner()
+    let res = runner.doString("g = 42; return g")
+    @Expect(res, "42")
+}
+
+@Test
+func testDoStringNoReturn(): Unit {
+    let runner = LuaRunner()
+    try {
+        runner.doString("x = 10")
+        fail("Should throw bad ret error")
+    } catch (e: LuaError) {
+        @Expect(e.code, 5011)
+    }
+}
+
+@Test
+func testDoStringSyntaxError(): Unit {
+    let runner = LuaRunner()
+    try {
+        runner.doString("if true then")
+        fail("Should throw syntax error")
+    } catch (e: LuaError) {
+        @Expect(e.code, 5020)
+    }
+}
+
+@Test
+func testDoStringNilReturn(): Unit {
+    let runner = LuaRunner()
+    try {
+        runner.doString("return nil")
+        fail("Should throw bad ret error")
+    } catch (e: LuaError) {
+        @Expect(e.code, 5011)
+    }
+}
+
+// ====================
+// 7. 错误码与回调
 // ====================
 
 @Test