Board-generation from strings, and vice-versa

src/index.js

@@ -112,13 +112,23 @@ class Piece {
 class Board extends React.Component {
   constructor(props) {
     super(props);
-    this.state = {
-      squares: this.reset(),
-      blackIsNext: true,
-      hand: {
-        heldPiece: null,
-      },
-    };
+    if (props && props.text) {
+      this.state = {
+        squares: this.stateFromText(props.text),
+        blackIsNext: true,
+        hand: {
+          heldPiece: null,
+        },
+      };
+    } else {
+      this.state = {
+        squares: this.reset(),
+        blackIsNext: true,
+        hand: {
+          heldPiece: null,
+        },
+      };
+    }
   }
 
   setHand(hand) {
@@ -139,6 +149,63 @@ class Board extends React.Component {
     return board;
   }
 
+  stateFromText(text) {
+    text = text.replace(/[\n]+/g, '');
+    const squares = text.substring(1);
+    return {
+      hand: null,
+      blackIsNext: text[0].toUpperCase() === 'B',
+      squares: squares.split('').map(c => {
+        const type = c.toLowerCase();
+        const color = c === type ? WHITE : BLACK;
+        switch (type) {
+          case 'r':
+            return new Piece(color, ROOK);
+          case 'n':
+            return new Piece(color, KNIGHT);
+          case 'b':
+            return new Piece(color, BISHOP);
+          case 'q':
+            return new Piece(color, QUEEN);
+          case 'k':
+            return new Piece(color, KING);
+          case 'p':
+            return new Piece(color, PAWN);
+          default:
+            return null;
+        }
+      }),
+    };
+  }
+
+  textFromState() {
+    const turn = (this.state.blackIsNext? 'B' : 'W');
+    return turn + this.state.squares.map(square => {
+      if (!square) {
+        return '_';
+      }
+      let color = (c) => {
+        return square.color === BLACK ? c.toUpperCase() : c;
+      };
+      switch (square.type) {
+        case ROOK:
+          return color('r');
+        case KNIGHT:
+          return color('n');
+        case BISHOP:
+          return color('b');
+        case QUEEN:
+          return color('q');
+        case KING:
+          return color('k');
+        case PAWN:
+          return color('p');
+        default:
+          return '_';
+      }
+    }).join('');;
+  }
+
   reset() {
     let squares = [];
     const mainRow = [ROOK, KNIGHT, BISHOP, QUEEN, KING, BISHOP, KNIGHT, ROOK];