feat: JsonWriter/JsonReader 支持 DateTime 字段(序列化为 yyyy-MM-dd HH:mm:ss 字符串,可反序列化回,含 Option<DateTime>)

.gitignore

@@ -1,2 +1,5 @@
 target/
-*.cj.macrocall
+*.cj.macrocall
+# 宏编译产物（构建时自动生成，不入库）
+src/macros/*.cjo
+src/macros/*.dll

src/json/JsonReader.cj

@@ -12,6 +12,7 @@ package simcu::serialization.json
 import std.collection.*
 import std.convert.*
 import std.reflect.*
+import std.time.*
 import stdx.encoding.json.*
 import simcu::serialization.common.ReflectionCache
 import simcu::serialization.common.FieldMetadata
@@ -62,6 +63,7 @@ public class JsonReader {
             case "Float64" => return readFloat64(value)
             case "Float32" => return Float32(readFloat64(value))
             case "Rune" => return readChar(value)
+            case "DateTime" | "std.time.DateTime" => return readDateTime(value)
             case _ => ()
         }
 
@@ -298,6 +300,15 @@ public class JsonReader {
         throw Exception("JsonSerializer: 无法转换为 Char")
     }
 
+    private static func readDateTime(v: JsonValue): DateTime {
+        let s = readString(v)
+        try {
+            return DateTime.parse(s, "yyyy-MM-dd HH:mm:ss")
+        } catch (_: Exception) {
+            throw Exception("JsonSerializer: 无法转换为 DateTime: ${s}")
+        }
+    }
+
     /// 生成某类型的占位默认值（用于构造 Option<X> 的 None：None 的参数槽类型是 X）。
     private static func defaultValueFor(typeName: String): Any {
         match (typeName) {
@@ -314,6 +325,7 @@ public class JsonReader {
             case "Float64" => return Float64(0.0)
             case "Float32" => return Float32(0.0)
             case "Rune" => return Rune(0)
+            case "DateTime" | "std.time.DateTime" => return DateTime.parse("1970-01-01 00:00:00", "yyyy-MM-dd HH:mm:ss")
             case _ => ()
         }
         // 集合/对象/枚举：反射无参构造；失败则抛异常

src/json/JsonWriter.cj

@@ -10,6 +10,7 @@ package simcu::serialization.json
 
 import std.collection.*
 import std.reflect.*
+import std.time.*
 import stdx.encoding.json.*
 import simcu::serialization.common.ReflectionCache
 import simcu::serialization.common.FieldMetadata
@@ -42,6 +43,7 @@ public class JsonWriter {
         if (let u64: UInt64 <- value) { return JsonInt(Int64(u64)) }
         if (let f32: Float32 <- value) { return JsonFloat(Float64(f32)) }
         if (let c: Rune <- value) { return JsonString("${c}") }
+        if (let dt: DateTime <- value) { return JsonString(dt.format("yyyy-MM-dd HH:mm:ss")) }
 
         let typeName = TypeInfo.of(value).toString()
 

src/tests/JsonSerializer_test.cj

@@ -11,6 +11,7 @@
 package simcu::serialization.tests
 
 import std.collection.*
+import std.time.*
 import std.unittest.*
 import std.unittest.testmacro.*
 import simcu::serialization.*
@@ -55,6 +56,13 @@ class User <: BaseUser {
     public var temp: String = "secret" // 无下划线 + 忽略
 }
 
+// DateTime 字段测试实体
+class Event {
+    public var _name: String = ""
+    public var _time: DateTime = DateTime.parse("1970-01-01 00:00:00", "yyyy-MM-dd HH:mm:ss")
+    public var _optTime: ?DateTime = None
+}
+
 // 多层继承：爷（标宏）→ 父（不标宏）→ 子
 @SerializerParent
 open class GrandParent {
@@ -304,6 +312,35 @@ public class JsonSerializerTests {
         }
     }
 
+    /// DateTime：输出 yyyy-MM-dd HH:mm:ss 字符串并可反序列化回
+    @TestCase
+    public func dateTimeRoundTrip(): Unit {
+        let e = Event()
+        e._name = "login"
+        e._time = DateTime.parse("2026-08-21 02:27:48", "yyyy-MM-dd HH:mm:ss")
+        e._optTime = Some(DateTime.parse("2026-01-02 03:04:05", "yyyy-MM-dd HH:mm:ss"))
+        let json = JsonSerializer.Serialize(e)
+        @Expect(json.contains("\"_time\": \"2026-08-21 02:27:48\""), true)
+        @Expect(json.contains("\"_optTime\": \"2026-01-02 03:04:05\""), true)
+        let back = JsonSerializer.Deserialize<Event>(json)
+        @Expect(back._time.format("yyyy-MM-dd HH:mm:ss"), "2026-08-21 02:27:48")
+        let optVal: ?DateTime = back._optTime
+        @Expect(optVal.isSome(), true)
+        if (let Some(dt) <- optVal) {
+            @Expect(dt.format("yyyy-MM-dd HH:mm:ss"), "2026-01-02 03:04:05")
+        }
+        // 顶层 DateTime 直接序列化
+        @Expect(JsonSerializer.Serialize(back._time), "\"2026-08-21 02:27:48\"")
+        // Option<DateTime> None → null
+        let e2 = Event()
+        e2._name = "n"
+        e2._time = DateTime.parse("2026-01-01 00:00:00", "yyyy-MM-dd HH:mm:ss")
+        let json2 = JsonSerializer.Serialize(e2)
+        @Expect(json2.contains("\"_optTime\": null"), true)
+        let back2 = JsonSerializer.Deserialize<Event>(json2)
+        @Expect(back2._optTime.isNone(), true)
+    }
+
     /// 宽松类型转换：JSON 数字 ↔ 字符串字段互转
     @TestCase
     public func looseConversion(): Unit {