edit/revertCell (#268)

// edit/dispose -------------------------------------------------------------------------------
export interface EditDisposeParams extends IEditSessionOperationParams { }
export interface EditDisposeResult { }

* Initial plumbing for edit/revertCell

* Implementation of revert cell in the parents of the row edit base

* Adding unit tests

src/Microsoft.SqlTools.ServiceLayer/EditData/UpdateManagement/RowCreate.cs

@@ -27,7 +27,7 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
         private const string InsertCompleteScript = "{0} VALUES ({1})";
         private const string InsertCompleteOutput = "{0} OUTPUT {1} VALUES ({2})";
 
-        private readonly CellUpdate[] newCells;
+        internal readonly CellUpdate[] newCells;
 
         /// <summary>
         /// Creates a new Row Creation edit to the result set
@@ -159,6 +159,21 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
             return string.Format(InsertCompleteScript, start, joinedValues);
         }
 
+        /// <summary>
+        /// Reverts a cell to an unset value.
+        /// </summary>
+        /// <param name="columnId">The ordinal ID of the cell to reset</param>
+        /// <returns>The default value for the column, or null if no default is defined</returns>
+        public override string RevertCell(int columnId)
+        {
+            // Validate that the column can be reverted
+            Validate.IsWithinRange(nameof(columnId), columnId, 0, newCells.Length - 1);
+
+            // Remove the cell update from list of set cells
+            newCells[columnId] = null;
+            return null;                // @TODO: Return default value when we have support checked in
+        }
+
         /// <summary>
         /// Sets the value of a cell in the row to be added
         /// </summary>

src/Microsoft.SqlTools.ServiceLayer/EditData/UpdateManagement/RowDelete.cs

@@ -81,6 +81,16 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
             return GetCommandText(GetWhereClause(false).CommandText);
         }
 
+        /// <summary>
+        /// This method should not be called. A cell cannot be reverted on a row that is pending
+        /// deletion.
+        /// </summary>
+        /// <param name="columnId">Ordinal of the column to update</param>
+        public override string RevertCell(int columnId)
+        {
+            throw new InvalidOperationException(SR.EditDataDeleteSetCell);
+        }
+
         /// <summary>
         /// This method should not be called. A cell cannot be updated on a row that is pending
         /// deletion.

src/Microsoft.SqlTools.ServiceLayer/EditData/UpdateManagement/RowEdit.cs

@@ -91,6 +91,13 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
         /// <returns>A SQL statement</returns>
         public abstract string GetScript();
 
+        /// <summary>
+        /// Reverts a specific cell in row with pending edits
+        /// </summary>
+        /// <param name="columnId">Ordinal ID of the column to revert</param>
+        /// <returns>String value of the original value of the cell</returns>
+        public abstract string RevertCell(int columnId);
+
         /// <summary>
         /// Changes the value a cell in the row.
         /// </summary>

src/Microsoft.SqlTools.ServiceLayer/EditData/UpdateManagement/RowUpdate.cs

@@ -4,6 +4,7 @@
 //
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
@@ -29,7 +30,7 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
         private const string UpdateScript = @"{0} SET {1} {2}";
         private const string UpdateScriptOutput = @"{0} SET {1} OUTPUT {2} {3}";
 
-        private readonly Dictionary<int, CellUpdate> cellUpdates;
+        internal readonly ConcurrentDictionary<int, CellUpdate> cellUpdates;
         private readonly IList<DbCellValue> associatedRow;
 
         /// <summary>
@@ -41,7 +42,7 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
         public RowUpdate(long rowId, ResultSet associatedResultSet, IEditTableMetadata associatedMetadata)
             : base(rowId, associatedResultSet, associatedMetadata)
         {
-            cellUpdates = new Dictionary<int, CellUpdate>();
+            cellUpdates = new ConcurrentDictionary<int, CellUpdate>();
             associatedRow = associatedResultSet.GetRow(rowId);
         }
 
@@ -137,6 +138,22 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
             return string.Format(UpdateScript, statementStart, setClause, whereClause);
         }
 
+        /// <summary>
+        /// Reverts the value of a cell to its original value
+        /// </summary>
+        /// <param name="columnId">Ordinal of the column to revert</param>
+        /// <returns>The value that was </returns>
+        public override string RevertCell(int columnId)
+        {
+            Validate.IsWithinRange(nameof(columnId), columnId, 0, associatedRow.Count - 1);
+
+            // Remove the cell update
+            CellUpdate cellUpdate;
+            cellUpdates.TryRemove(columnId, out cellUpdate);
+
+            return associatedRow[columnId].DisplayValue;
+        }
+
         /// <summary>
         /// Sets the value of the cell in the associated row. If <paramref name="newValue"/> is
         /// identical to the original value, this will remove the cell update from the row update.
@@ -157,11 +174,9 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
             // NOTE: We must use .Equals in order to ignore object to object comparisons
             if (update.Value.Equals(associatedRow[columnId].RawObject))
             {
-                // Remove any pending change and stop processing this
-                if (cellUpdates.ContainsKey(columnId))
-                {
-                    cellUpdates.Remove(columnId);
-                }
+                // Remove any pending change and stop processing this (we don't care if we fail to remove something)
+                CellUpdate cu;
+                cellUpdates.TryRemove(columnId, out cu);
                 return new EditUpdateCellResult
                 {
                     HasCorrections = false,
@@ -172,7 +187,7 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
             }
 
             // The change is real, so set it
-            cellUpdates[columnId] = update;
+            cellUpdates.AddOrUpdate(columnId, update, (i, cu) => update);
             return new EditUpdateCellResult
             {
                 HasCorrections = update.ValueAsString != newValue,