Improve `CheckableResponse`

mirai-core-utils/src/commonMain/kotlin/CheckableResult.kt

@@ -28,6 +28,17 @@ public abstract class CheckableResponseA : CheckableResponse {
     final override val _errorMessage: String? get() = errorMessage
 }
 
+@Serializable
+public abstract class CheckableResponseB : CheckableResponse {
+    public abstract val result: Int
+
+    @Suppress("SpellCheckingInspection")
+    public abstract val errmsg: String
+
+    final override val _errorCode: Int get() = result
+    final override val _errorMessage: String get() = errmsg
+}
+
 public class DeserializationFailure(
     structType: KType,
     public val json: String,
@@ -40,17 +51,42 @@ public class DeserializationFailure(
     }
 }
 
-public fun <T : CheckableResponse> T.checked(): T {
+/*
+ * `check`: throws exception, or returns succeed value.
+ * `checked`: do `check` and wrap result into an `Either`.
+ */
+
+public fun <T : CheckableResponse> T.check(): T {
     check(_errorCode == 0) { "Error code: $_errorCode, Error message: $_errorMessage" }
     return this
 }
 
-public fun DeserializationFailure.checked(): Nothing = throw this.createException()
+public open class FailureResponse(
+    public val errorCode: Int,
+    public val errorMessage: String,
+) {
+    public fun createException(): Exception {
+        return IllegalStateException("Error code: $errorCode, Error message: $errorMessage")
+    }
+}
+
+public inline fun <reified T : CheckableResponse> T.checked(): Either<FailureResponse, T> {
+    if (_errorCode == 0) return Either<FailureResponse, T>(this)
+    return Either(FailureResponse(_errorCode, _errorMessage.toString()))
+}
+
+public fun DeserializationFailure.check(): Nothing = throw this.createException()
+public fun FailureResponse.check(): Nothing = throw this.createException()
+
+public inline fun <reified T : CheckableResponse> Either<DeserializationFailure, T>.check(): T {
+    return this.fold(onLeft = { it.check() }, onRight = { it.check() })
+}
 
-public inline fun <reified T : CheckableResponse> Either<DeserializationFailure, T>.checked(): T {
-    return this.fold(onLeft = { it.checked() }, onRight = { it.checked() })
+public inline fun <reified T> Either<DeserializationFailure, T>.check(): T {
+    return this.fold(onLeft = { it.check() }, onRight = { it })
 }
 
-public inline fun <reified T> Either<DeserializationFailure, T>.checked(): T {
-    return this.fold(onLeft = { it.checked() }, onRight = { it })
+@JvmName("checkedFailureResponseT")
+public inline fun <reified T> Either<FailureResponse, T>.check(): T {
+    return this.fold(onLeft = { it.check() }, onRight = { it })
 }

mirai-core/src/commonMain/kotlin/contact/announcement/AnnouncementsImpl.kt

@@ -188,8 +188,8 @@ internal object AnnouncementProtocol {
             cookie("p_uin", "o$id")
             cookie("skey", sKey)
             cookie("p_skey", psKey("qun.qq.com"))
-        }.loadSafelyAs(UploadImageResp.serializer()).checked()
-        return resp.id.replace(""", "\"").loadSafelyAs(GroupAnnouncementImage.serializer()).checked().toPublic()
+        }.loadSafelyAs(UploadImageResp.serializer()).check()
+        return resp.id.replace(""", "\"").loadSafelyAs(GroupAnnouncementImage.serializer()).check().toPublic()
     }
 
     @Serializable
@@ -233,7 +233,7 @@ internal object AnnouncementProtocol {
             cookie("p_uin", "o$id")
             cookie("skey", sKey)
             cookie("p_skey", psKey("qun.qq.com"))
-        }.loadSafelyAs(SendGroupAnnouncementResp.serializer()).checked().fid
+        }.loadSafelyAs(SendGroupAnnouncementResp.serializer()).check().fid
     }
 
     suspend fun QQAndroidBot.getRawGroupAnnouncements(
@@ -271,7 +271,7 @@ internal object AnnouncementProtocol {
             cookie("p_uin", "o$id")
             cookie("skey", sKey)
             cookie("p_skey", psKey("qun.qq.com"))
-        }.loadSafelyAs(DeleteResp.serializer()).checked()
+        }.loadSafelyAs(DeleteResp.serializer()).check()
         return true
     }
 

mirai-core/src/commonMain/kotlin/network/protocol/data/proto/MsgSvc.kt

@@ -13,6 +13,7 @@ import kotlinx.serialization.Serializable
 import kotlinx.serialization.protobuf.ProtoNumber
 import net.mamoe.mirai.internal.network.Packet
 import net.mamoe.mirai.internal.utils.io.ProtoBuf
+import net.mamoe.mirai.utils.CheckableResponseB
 import net.mamoe.mirai.utils.EMPTY_BYTE_ARRAY
 
 @Serializable
@@ -650,14 +651,14 @@ internal class MsgSvc : ProtoBuf {
 
     @Serializable
     internal class PbGetRoamMsgResp(
-        @ProtoNumber(1) @JvmField val result: Int = 0,
-        @ProtoNumber(2) @JvmField val errmsg: String = "",
+        @ProtoNumber(1) override val result: Int = 0,
+        @ProtoNumber(2) override val errmsg: String = "",
         @ProtoNumber(3) @JvmField val peerUin: Long = 0L,
         @ProtoNumber(4) @JvmField val lastMsgtime: Long = 0L,
         @ProtoNumber(5) @JvmField val random: Long = 0L,
         @ProtoNumber(6) @JvmField val msg: List<MsgComm.Msg> = emptyList(),
         @ProtoNumber(7) @JvmField val sig: ByteArray = EMPTY_BYTE_ARRAY,
-    ) : ProtoBuf
+    ) : ProtoBuf, CheckableResponseB()
 
     @Serializable
     internal class PbDiscussReadedReportReq(