Feature: isSolved method (#9)

* Bump to v2.2.0

README.md

@@ -109,3 +109,7 @@ Changes the current grid state to the next recorded grid state (if one exists).
 ### reset()
 
 Resets the current grid to the original grid state and wipes the rest of the grid history.
+
+### isSolved()
+
+`true` if all cells have values in them, otherwise `false`.

package.json

@@ -1,6 +1,6 @@
 {
     "name": "sudoku-grid-maker",
-    "version": "2.1.1",
+    "version": "2.2.0",
     "author": "MaoShizhong",
     "description": "A playable sudoku grid maker (not generator). Supports pencil marks and grid history for undo/redo.",
     "repository": {

src/index.ts

@@ -92,6 +92,12 @@ class Sudoku {
         this.grid = this.history.currentGridState;
     }
 
+    isSolved(): boolean {
+        return this.grid.every((row): boolean =>
+            row.every((cell) => cell.value)
+        );
+    }
+
     #checkPlacementValidity(
         targetCell: Cell,
         number: SudokuNumber

src/tests/sudoku.test.ts

@@ -299,3 +299,42 @@ describe('Number/pencil mark interactions', (): void => {
         expect(sudoku.grid[3][3].pencilMarks.includes(9)).toBe(false);
     });
 });
+
+describe('Solved state', (): void => {
+    const almostSolvedStartingValues: CellValue[][] = [
+        [null, 2, 5, 6, 3, 1, 8, 4, 7],
+        [6, 1, 8, 5, 7, 4, 2, 9, 3],
+        [3, 7, 4, 9, 8, 2, 5, 6, 1],
+        [7, 4, 9, 8, 2, 6, 1, 3, 5],
+        [8, 5, 2, 4, 1, 3, 9, 7, 6],
+        [1, 6, 3, 7, 9, 5, 4, 8, 2],
+        [2, 8, 7, 3, 5, 9, 6, 1, 4],
+        [4, 9, 1, 2, 6, 7, 3, 5, 8],
+        [5, 3, 6, 1, 4, 8, 7, 2, 9],
+    ];
+    const solvedStartingValues: CellValue[][] = [
+        [9, 2, 5, 6, 3, 1, 8, 4, 7],
+        [6, 1, 8, 5, 7, 4, 2, 9, 3],
+        [3, 7, 4, 9, 8, 2, 5, 6, 1],
+        [7, 4, 9, 8, 2, 6, 1, 3, 5],
+        [8, 5, 2, 4, 1, 3, 9, 7, 6],
+        [1, 6, 3, 7, 9, 5, 4, 8, 2],
+        [2, 8, 7, 3, 5, 9, 6, 1, 4],
+        [4, 9, 1, 2, 6, 7, 3, 5, 8],
+        [5, 3, 6, 1, 4, 8, 7, 2, 9],
+    ];
+
+    it('does not report an unfinished grid as solved', (): void => {
+        const sudoku = new Sudoku(almostSolvedStartingValues);
+        expect(sudoku.isSolved()).toBe(false);
+    });
+
+    it('reports an finished grid as solved', (): void => {
+        const sudoku = new Sudoku(almostSolvedStartingValues);
+        sudoku.addNumber({ newNumber: 9, row: 0, column: 0 });
+        expect(sudoku.isSolved()).toBe(true);
+
+        const preSolvedSudoku = new Sudoku(solvedStartingValues);
+        expect(preSolvedSudoku.isSolved()).toBe(true);
+    });
+});