From 127dea25b41a1ac8b78fc29f4db6bae316090cc3 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Mon, 1 Apr 2024 20:28:16 +0100
Subject: [PATCH] Add validation error detail in 'FenError'

---
 src/board/chess_board/mod.rs |  4 ++--
 src/fen.rs                   | 13 ++++++-------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/board/chess_board/mod.rs b/src/board/chess_board/mod.rs
index d51eabb..d1d3751 100644
--- a/src/board/chess_board/mod.rs
+++ b/src/board/chess_board/mod.rs
@@ -485,8 +485,8 @@ impl FromFen for ChessBoard {
             side,
         };
 
-        if !res.is_valid() {
-            return Err(FenError::InvalidPosition);
+        if let Err(err) = res.validate() {
+            return Err(FenError::InvalidPosition(err));
         }
 
         Ok(res)
diff --git a/src/fen.rs b/src/fen.rs
index d8af180..3034003 100644
--- a/src/fen.rs
+++ b/src/fen.rs
@@ -1,4 +1,4 @@
-use crate::board::{CastleRights, Color, File, Piece, Rank, Square};
+use crate::board::{CastleRights, Color, File, InvalidError, Piece, Rank, Square};
 
 /// A trait to mark items that can be converted from a FEN input.
 pub trait FromFen: Sized {
@@ -13,16 +13,15 @@ pub enum FenError {
     /// Invalid FEN input.
     InvalidFen,
     /// Invalid chess position.
-    InvalidPosition,
+    InvalidPosition(InvalidError),
 }
 
 impl std::fmt::Display for FenError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let error_msg = match self {
-            Self::InvalidFen => "Invalid FEN input",
-            Self::InvalidPosition => "Invalid chess position",
-        };
-        write!(f, "{}", error_msg)
+        match self {
+            Self::InvalidFen => write!(f, "Invalid FEN input"),
+            Self::InvalidPosition(err) => write!(f, "Invalid chess position: {}", err),
+        }
     }
 }