fix #13

src/analysis.js

@@ -116,10 +116,10 @@ export function group(board, position) {
 
     while (!queue.isEmpty()) {
         const current = queue.first();
-        const more_matching = matchingAdjacentPositions(board, position);
+        const more_matching = matchingAdjacentPositions(board, current);
 
-        queue = queue.rest().union(more_matching.subtract(found));
         found = found.add(current);
+        queue = queue.rest().union(more_matching.subtract(found));
     }
 
     return found;
@@ -176,6 +176,34 @@ export function isLegalMove(board, position, color) {
 }
 
 
+/**
+ * @private
+ */
+export function prettyString(board) {
+    const size = board.get(SIZE_KEY);
+    let pretty_string = '';
+
+    for (var i = 0; i < size; i++) {
+        for (var j = 0; j < size; j++) {
+            let color = board.get(List.of(i, j), EMPTY);
+            switch(color) {
+                case BLACK:
+                    pretty_string += 'O';
+                    break;
+                case WHITE:
+                    pretty_string += 'X';
+                    break;
+                case EMPTY:
+                    pretty_string += '+';
+                    break;
+            }
+        }
+        pretty_string += '\n';
+    }
+    return pretty_string;
+}
+
+
 export default {
     isLegalMove, oppositeColor, liberties, group
 };

src/board.js

@@ -3,7 +3,7 @@ import {Map, List} from 'immutable';
 import {isPositiveInteger} from './utils';
 import {
     SIZE_KEY, allPossibleMoves, group, liberties, isLegalMove,
-    BLACK, WHITE, EMPTY,
+    BLACK, WHITE, EMPTY, prettyString,
 } from './analysis';
 import {
     emptyBoard, addBlackMove, addWhiteMove, addMove, removeMoves,
@@ -204,26 +204,6 @@ export class Board {
      * @returns {string} ASCII board
      */
     toPrettyString() {
-        const size = this.board_size;
-        let pretty_string = '';
-
-        for (var i = 0; i < this.board_size; i++) {
-            for (var j = 0; j < this.board_size; j++) {
-                let color = this.positions.get(List.of(i, j), EMPTY);
-                switch(color) {
-                    case BLACK:
-                        pretty_string += 'O';
-                        break;
-                    case WHITE:
-                        pretty_string += 'X';
-                        break;
-                    case EMPTY:
-                        pretty_string += '+';
-                        break;
-                }
-            }
-            pretty_string += '\n';
-        }
-        return pretty_string;
+        return prettyString(this.positions);
     }
 }

src/utils.js

@@ -1,5 +1,6 @@
 import {isNumber} from 'lodash';
 
+
 /**
  * @private
  */

test/test_transforms.js

@@ -2,7 +2,7 @@ import assert from 'assert';
 import {List, Set} from 'immutable';
 
 import {emptyBoard, addMove, removeMoves} from '../src/transforms';
-import {SIZE_KEY, BLACK, WHITE} from '../src/analysis';
+import {SIZE_KEY, BLACK, WHITE, prettyString} from '../src/analysis';
 
 
 describe('empty board', function() {
@@ -71,6 +71,34 @@ describe('add move', function() {
             ]).equals(Set(new_board.keys()))
         );
     });
+
+    it('kills 3 stone group', function() {
+        const board = emptyBoard(5)
+            .set(List.of(0, 0), BLACK)
+            .set(List.of(0, 1), BLACK)
+            .set(List.of(0, 2), BLACK)
+            .set(List.of(1, 0), WHITE)
+            .set(List.of(1, 1), WHITE)
+            .set(List.of(1, 2), WHITE)
+            .set(List.of(2, 0), BLACK)
+            .set(List.of(2, 1), BLACK)
+            .set(List.of(2, 2), BLACK);
+
+        const new_board = addMove(board, List.of(1, 3), BLACK);
+
+        assert.ok(
+            Set([
+                SIZE_KEY,
+                List.of(0, 0),
+                List.of(0, 1),
+                List.of(0, 2),
+                List.of(2, 0),
+                List.of(2, 1),
+                List.of(2, 2),
+                List.of(1, 3),
+            ]).equals(Set(new_board.keys()))
+        );
+    });
 });