implement /api/solve route

controllers/sudoku-solver.js

@@ -6,7 +6,11 @@ class SudokuSolver {
 
     validate(puzzleString) {
 
-        return puzzleString.length == 81 && !puzzleString.match(/[^\.\d]/g);
+        if (puzzleString.length != 81) return 'Expected puzzle to be 81 characters long';
+
+        if (puzzleString.match(/[^\.\d]/g)) return 'Invalid characters in puzzle';
+
+        return true;
 
     }
 
@@ -173,7 +177,7 @@ class SudokuSolver {
 
     solve(puzzleString) {
 
-        if (!this.validate(puzzleString)) return false;
+        if (this.validate(puzzleString) != true) return false;
 
         // create character array
         let puzzle = puzzleString.split('');
@@ -312,6 +316,7 @@ class SudokuSolver {
         let board = generateBoard(puzzle);
         let solution = solveFromCell(board, 0, 0);
         
+        if (solution == false) return false;
         return solution.flat().join('');
 
     }

routes/api.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const SudokuSolver = require('../controllers/sudoku-solver.js');
+const SudokuSolver = require('../controllers/sudoku-solver');
 
 module.exports = function (app) {
 
@@ -15,9 +15,18 @@ module.exports = function (app) {
         .post((req, res) => {
 
             const puzzleString = req.body.puzzle;
-            console.log(puzzleString);
 
+            if (puzzleString == undefined) return res.status(200).json({error: 'Required field missing' });
 
+            const validate = solver.validate(puzzleString);
+
+            if (validate != true) return res.status(200).json({error: validate});
+
+            const solution = solver.solve(puzzleString);
+            
+            if (solution == false) return res.status(200).json({error: 'Puzzle cannot be solved'});
+
+            return res.status(200).json({solution: solution});
 
         });
 };

tests/1_unit-tests.js

@@ -20,7 +20,7 @@ suite('UnitTests', () => {
 
         const input = puzzlesAndSolutions[0][0].replace(/\./g, '?');
 
-        assert.equal(solver.validate(input), false);
+        assert.equal(solver.validate(input), 'Invalid characters in puzzle');
         done();
 
     });
@@ -29,7 +29,7 @@ suite('UnitTests', () => {
 
         const input = puzzlesAndSolutions[0][0] + '0';
 
-        assert.equal(solver.validate(input), false);
+        assert.equal(solver.validate(input), 'Expected puzzle to be 81 characters long');
         done();
 
     });