Close DDD cleanup and tests-support closure

server-rs/crates/module-npc/src/errors.rs

@@ -1,3 +1,38 @@
-//! NPC 领域错误过渡落位。
+//! NPC 领域错误。
 //!
 //! 错误只表达互动规则失败，例如状态不允许、好感不足或目标非法。
+
+use std::{error::Error, fmt};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum NpcStateFieldError {
+    MissingRuntimeSessionId,
+    MissingNpcId,
+    MissingNpcName,
+    MissingInteractionFunctionId,
+    HelpAlreadyUsed,
+    RecruitAffinityTooLow,
+    UnsupportedInteractionFunctionId,
+}
+
+impl fmt::Display for NpcStateFieldError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::MissingRuntimeSessionId => f.write_str("npc_state.runtime_session_id 不能为空"),
+            Self::MissingNpcId => f.write_str("npc_state.npc_id 不能为空"),
+            Self::MissingNpcName => f.write_str("npc_state.npc_name 不能为空"),
+            Self::MissingInteractionFunctionId => {
+                f.write_str("resolve_npc_interaction.interaction_function_id 不能为空")
+            }
+            Self::HelpAlreadyUsed => f.write_str("npc_state.help_used 已经消耗，不能重复援手"),
+            Self::RecruitAffinityTooLow => {
+                f.write_str("npc_state.affinity 未达到招募阈值，不能执行招募动作")
+            }
+            Self::UnsupportedInteractionFunctionId => {
+                f.write_str("resolve_npc_interaction.interaction_function_id 当前不受支持")
+            }
+        }
+    }
+}
+
+impl Error for NpcStateFieldError {}