Fixed issues in code reported by Codacy.

Author: kurtanr

README.md

@@ -1,8 +1,8 @@
 # SimpleSudokuSolver
 
-[![Codacy Badge](https://api.codacy.com/project/badge/Grade/607feb9c1fd2454997e89ba592c345c4)](https://app.codacy.com/app/kurtanr/SimpleSudokuSolver?utm_source=github.com&utm_medium=referral&utm_content=kurtanr/SimpleSudokuSolver&utm_campaign=Badge_Grade_Settings)
 [![Build](https://img.shields.io/appveyor/ci/kurtanr/SimpleSudokuSolver.svg)](https://ci.appveyor.com/project/kurtanr/SimpleSudokuSolver)
 [![Codecov](https://img.shields.io/codecov/c/gh/kurtanr/SimpleSudokuSolver)](https://codecov.io/gh/kurtanr/SimpleSudokuSolver)
+[![Codacy grade](https://img.shields.io/codacy/grade/607feb9c1fd2454997e89ba592c345c4)](https://app.codacy.com/app/kurtanr/SimpleSudokuSolver)
 [![Nuget](https://img.shields.io/nuget/v/SimpleSudokuSolver.svg?color=green)](https://www.nuget.org/packages/SimpleSudokuSolver/)
 [![License](https://img.shields.io/github/license/kurtanr/SimpleSudokuSolver.svg)](https://github.com/kurtanr/SimpleSudokuSolver/blob/master/LICENSE)
 
@@ -17,12 +17,12 @@ Repository contains tests for the library and a UI which uses the library and ca
 </p>
 
 Out of the well known [Sudoku Solving Techniques](https://sudoku9x9.com/sudoku_solving_techniques_9x9.html), the solver currently implements:
-* Hidden Single
-* Naked Single
-* Locked Candidates
-* Naked Pair
-* Naked Triple
-* Naked Quad
-* Hidden Pair
-* Hidden Triple
-* Hidden Quad
+*   Hidden Single
+*   Naked Single
+*   Locked Candidates
+*   Naked Pair
+*   Naked Triple
+*   Naked Quad
+*   Hidden Pair
+*   Hidden Triple
+*   Hidden Quad

SimpleSudokuSolver.Tests/Model/SudokuPuzzleTests.cs

@@ -236,7 +236,7 @@ public void ApplyValidSingleStepSolutionTest()
       Assert.That(sudokuPuzzle.Steps.Count, Is.EqualTo(2));
       Assert.That(sudokuPuzzle.NumberOfSteps, Is.EqualTo(2));
       Assert.That(sudokuPuzzle.Steps.Last().Strategy, Is.EqualTo(strategyWhichFindsResult.StrategyName));
-      Assert.That(sudokuPuzzle.Cells[4,7].Value, Is.EqualTo(5));
+      Assert.That(sudokuPuzzle.Cells[4, 7].Value, Is.EqualTo(5));
       Assert.That(sudokuPuzzle.Steps.Last().SolutionDescription, Is.Not.Empty);
     }
 
@@ -286,7 +286,7 @@ public void UndoSingleStepSolutionsWhichReturnsEliminations_UndoesEliminations_T
       Assert.That(step.Result, Is.Null);
       Assert.That(step.Strategy, Is.EqualTo(strategyWhichReducesCandidates.StrategyName));
       Assert.That(step.SolutionDescription, Is.Not.Empty);
-      CollectionAssert.AreEqual(sudokuPuzzle.Cells[4, 7].CanBe, new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 });
+      CollectionAssert.AreEqual(sudokuPuzzle.Cells[4, 7].CanBe, new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 });
     }
 
     [Test]

SimpleSudokuSolver.Tests/SingleStepSolutionTests.cs

@@ -16,6 +16,7 @@ public void CandidateEqualityTest()
       Assert.That(null != candidate);
       Assert.That(candidate == otherCandidate);
       Assert.That(candidate.Equals(otherCandidate));
+      Assert.That(candidate.Equals((object)otherCandidate));
       Assert.That(candidate.GetHashCode() == otherCandidate.GetHashCode());
 
       var rowDiffers = new SingleStepSolution.Candidate(0, 2, 3);

SimpleSudokuSolver.UI/MainWindow.xaml.cs

@@ -45,7 +45,7 @@ private SudokuPuzzle OnLoadGame()
 
     private void OnSaveGame(SudokuPuzzle sudokuPuzzle)
     {
-      var saveFileDialog = new SaveFileDialog()
+      var saveFileDialog = new SaveFileDialog
       {
         Filter = _dialogFilter
       };

SimpleSudokuSolver.UI/ViewModel/CellViewModel.cs

@@ -1,5 +1,4 @@
 using SimpleSudokuSolver.Model;
-using System;
 using System.ComponentModel;
 
 namespace SimpleSudokuSolver.UI.ViewModel
@@ -48,7 +47,7 @@ public string Value
       get { return Cell.Value != 0 ? Cell.Value.ToString() : string.Empty; }
     }
 
-    public CellViewModel(Cell cell, bool showTooltip = false)
+    public CellViewModel(Cell cell, bool showTooltip)
     {
       Cell = cell;
       ShowTooltip = showTooltip;

SimpleSudokuSolver/DefaultSolver.cs

@@ -6,7 +6,7 @@ namespace SimpleSudokuSolver
   /// <summary>
   /// Default sudoku solver.
   /// </summary>
-  public partial class DefaultSolver : ISudokuSolver
+  public class DefaultSolver : ISudokuSolver
   {
     private SudokuPuzzle _sudokuPuzzleAfterFailedSolveSingleStep;
     private readonly BasicElimination _basicElimination = new BasicElimination();

SimpleSudokuSolver/PuzzleProviders/SudokuFilePuzzleProvider.cs

@@ -58,14 +58,15 @@ public SudokuFilePuzzleProvider(string filePath)
     private int[] GetRowElements(string row)
     {
       var separators = new[] { ",", " ", "\t" };
+      var rowWithSeparators = row;
 
       // if there are no separators, add them
       if (!separators.Any(x => row.Contains(x)))
       {
-        row = Regex.Replace(row, ".{1}", "$0,");
+        rowWithSeparators = Regex.Replace(rowWithSeparators, ".{1}", "$0,");
       }
 
-      return row.Split(separators, StringSplitOptions.RemoveEmptyEntries)
+      return rowWithSeparators.Split(separators, StringSplitOptions.RemoveEmptyEntries)
         .Where(x => !string.IsNullOrWhiteSpace(x.Trim()))
         .Select(x => int.Parse(x.Trim()))
         .ToArray();

SimpleSudokuSolver/SingleStepSolution.cs

@@ -1,4 +1,5 @@
-using System.Linq;
+using System;
+using System.Linq;
 using System.Text;
 
 namespace SimpleSudokuSolver
@@ -13,7 +14,7 @@ public class SingleStepSolution
     /// <summary>
     /// Contains value and zero-based row and column index of the cell.
     /// </summary>
-    public class Candidate
+    public class Candidate : IEquatable<Candidate>
     {
       public Candidate(int indexOfRow, int indexOfColumn, int value)
       {
@@ -66,10 +67,15 @@ public Candidate(int indexOfRow, int indexOfColumn, int value)
 
       public override bool Equals(object obj)
       {
-        return obj is Candidate candidate &&
-               IndexOfRow == candidate.IndexOfRow &&
-               IndexOfColumn == candidate.IndexOfColumn &&
-               Value == candidate.Value;
+        return Equals(obj as Candidate);
+      }
+
+      public bool Equals(Candidate other)
+      {
+        return other != null &&
+               IndexOfRow == other.IndexOfRow &&
+               IndexOfColumn == other.IndexOfColumn &&
+               Value == other.Value;
       }
 
       public override int GetHashCode()

SimpleSudokuSolver/Strategy/LockedCandidates.cs

@@ -25,7 +25,6 @@ public SingleStepSolution SolveSingleStep(SudokuPuzzle sudokuPuzzle)
       {
         var blockCells = block.Cells.OfType<Cell>();
         var cellsWithValue = blockCells.Where(x => x.HasValue).ToArray();
-        var cellsWithNoValue = blockCells.Where(x => !x.HasValue).ToArray();
         var possibleCellValuesInBlock = sudokuPuzzle.PossibleCellValues.Except(
           cellsWithValue.Select(x => x.Value)).ToArray();