Fixed NPE, added InsertColumn, extended test cases

Author: rabanti-github

NanoXLSX/Worksheet.cs

@@ -2629,13 +2629,14 @@ private static bool WorksheetExists(string name, Workbook workbook)
 
         #endregion
 
-#region Insert-Search-Replace
+        #region Insert-Search-Replace
 
         /// <summary>
-        /// Inserts 'count' rows below the specified 'rowNumber'.
-        /// The 'new' rows inherit the style of the row above.
-        /// Note: Formulas are not adjusted.
+        /// Inserts 'count' rows below the specified 'rowNumber'. Existing cells are moved down by the number of new rows.
+        /// The inserted, new rows inherits the style of the original cell at the defined row number.
+        /// The inserted cells are empty. The values can be set later
         /// </summary>
+        /// <remarks>Formulas / references are not adjusted</remarks>
         /// <param name="rowNumber">Row number below which the new row(s) will be inserted.</param>
         /// <param name="numberOfNewRows">Number of rows to insert.</param>
         public void InsertRow(int rowNumber, int numberOfNewRows)
@@ -2665,7 +2666,6 @@ public void InsertRow(int rowNumber, int numberOfNewRows)
                 this.Cells.Remove(cell.Key);
             }
 
-
             // Fill the gap with new cells, using the same style as the first row.
             foreach (Cell cell in upperRow)
             {
@@ -2686,11 +2686,62 @@ public void InsertRow(int rowNumber, int numberOfNewRows)
             }
         }
 
+        /// <summary>
+        /// Inserts 'count' columns right of the specified 'columnNumber'. Existing cells are moved to the right by the number of new columns.
+        /// The inserted, new columns inherits the style of the original cell at the defined column number.
+        /// The inserted cells are empty. The values can be set later
+        /// </summary>
+        /// <remarks>Formulas are not adjusted</remarks>
+        /// <param name="columnNumber">Column number right which the new column(s) will be inserted.</param>
+        /// <param name="numberOfNewColumns">Number of columns to insert.</param>
+        public void InsertColumn(int columnNumber, int numberOfNewColumns)
+        {
+            var leftColumn = this.GetColumn(columnNumber);
+            var cellsToChange = this.Cells.Where(c => c.Value.CellAddress2.Column > columnNumber).ToList();
+
+            Dictionary<string, Cell> newCells = new Dictionary<string, Cell>();
+            foreach (var cell in cellsToChange)
+            {
+                var row = cell.Value.CellAddress2.Row;
+                var col = cell.Value.CellAddress2.Column;
+                Address newAddress = new Address(col + numberOfNewColumns, row);
+
+                Cell newCell = new Cell(cell.Value.Value, cell.Value.DataType, newAddress);
+                if (cell.Value.CellStyle != null)
+                {
+                    newCell.SetStyle(cell.Value.CellStyle); // Apply the style from the "old" cell.
+                }
+                newCells.Add(newAddress.GetAddress(), newCell);
+
+                // Delete the original cells since the key cannot be changed.
+                this.Cells.Remove(cell.Key);
+            }
+
+            // Fill the gap with new cells, using the same style as the first row.
+            foreach (Cell cell in leftColumn)
+            {
+                for (int i = 0; i < numberOfNewColumns; i++)
+                {
+                    Address newAddress = new Address(cell.CellAddress2.Column + 1 + i, cell.CellAddress2.Row);
+                    Cell newCell = new Cell(null, Cell.CellType.EMPTY, newAddress);
+                    if (cell.CellStyle != null)
+                        newCell.SetStyle(cell.CellStyle);
+                    this.Cells.Add(newAddress.GetAddress(), newCell);
+                }
+            }
+
+            // Re-add the previous cells from the copy back with a new key.
+            foreach (KeyValuePair<string, Cell> cellKeyValue in newCells)
+            {
+                this.Cells.Add(cellKeyValue.Key, cellKeyValue.Value);  //cell.Value is the cell incl. Style etc.
+            }
+        }
+
         /// <summary>
         /// Searches for the first occurrence of the value.
         /// </summary>
         /// <param name="searchValue">The value to search for.</param>
-        /// <returns>The first cell containing the searched value or Null</returns>
+        /// <returns>The first cell containing the searched value or null if the value was not found</returns>
         public Cell FirstCellByValue(object searchValue)
         {
             var cell = this.Cells.FirstOrDefault(c =>
@@ -2704,12 +2755,11 @@ public Cell FirstCellByValue(object searchValue)
         /// Example: var cell = worksheet.FindCell(c => c.Value?.ToString().Contains("searchValue"));
         /// </summary>
         /// <param name="predicate"></param>
-        /// <returns>The first cell containing the searched value or Null</returns>
+        /// <returns>The first cell containing the searched value or null if the value was not found</returns>
         public Cell FirstOrDefaultCell(Func<Cell, bool> predicate)
         {
-            return this.Cells
-                .FirstOrDefault(c => predicate(c.Value))
-                .Value;
+            return this.Cells.Values
+                .FirstOrDefault(c => c != null && (c.Value == null || predicate(c)));
         }
 
         /// <summary>
@@ -2728,9 +2778,9 @@ public List<Cell> CellsByValue(object searchValue)
         /// <summary>
         /// Replaces all occurrences of 'oldValue' with 'newValue' and returns the number of replacements.
         /// </summary>
-        /// <param name="oldValue"></param>
-        /// <param name="newValue"></param>
-        /// <returns>Count of replaced Cell-Values</returns>
+        /// <param name="oldValue">Old value</param>
+        /// <param name="newValue">New value that should replace the old one</param>
+        /// <returns>Count of replaced Cell values</returns>
         public int ReplaceCellValue(object oldValue, object newValue)
         {
             int count = 0;