vi-mode: Use dk to delete the previous n logical lines and the current logical line in a multi-line buffer (#1737)

Author: springcomp

PSReadLine/KeyBindings.cs

@@ -403,6 +403,7 @@ public static KeyHandlerGroup GetDisplayGrouping(string function)
             case nameof(DeleteLine):
             case nameof(DeleteLineToFirstChar):
             case nameof(DeleteNextLines):
+            case nameof(DeletePreviousLines):
             case nameof(DeleteToEnd):
             case nameof(DeleteWord):
             case nameof(ForwardDeleteLine):

PSReadLine/KeyBindings.vi.cs

@@ -230,6 +230,7 @@ private void SetDefaultViBindings()
                 { Keys.ucE,             MakeKeyHandler( ViDeleteEndOfGlob,            "ViDeleteEndOfGlob") },
                 { Keys.H,               MakeKeyHandler( BackwardDeleteChar,           "BackwardDeleteChar") },
                 { Keys.J,               MakeKeyHandler( DeleteNextLines,              "DeleteNextLines") },
+                { Keys.K,               MakeKeyHandler( DeletePreviousLines,          "DeletePreviousLines") },
                 { Keys.L,               MakeKeyHandler( DeleteChar,                   "DeleteChar") },
                 { Keys.Space,           MakeKeyHandler( DeleteChar,                   "DeleteChar") },
                 { Keys._0,              MakeKeyHandler( BackwardDeleteLine,           "BackwardDeleteLine") },

PSReadLine/PSReadLineResources.resx

@@ -805,6 +805,9 @@ Or not saving history with:
   <data name="DeleteEndOfBufferDescription" xml:space="preserve">
     <value>Delete the current logical line and up to the end of the multiline buffer</value>
   </data>
+  <data name="DeletePreviousLinesDescription" xml:space="preserve">
+    <value>Deletes from the previous n logical lines in a multiline buffer to the current logical line included.</value>
+  </data>
   <data name="DeleteNextLinesDescription" xml:space="preserve">
     <value>Deletes the current and next n logical lines in a multiline buffer</value>
   </data>

PSReadLine/ReadLine.vi.cs

@@ -827,6 +827,28 @@ private static void DeleteNextLines(ConsoleKeyInfo? key = null, object arg = nul
             }
         }
 
+        /// <summary>
+        /// Deletes from the previous n logical lines to the current logical line included.
+        /// </summary>
+        public static void DeletePreviousLines(ConsoleKeyInfo? key = null, object arg = null)
+        {
+            if (TryGetArgAsInt(arg, out int requestedLineCount, 1))
+            {
+                var currentLineIndex = _singleton.GetLogicalLineNumber() - 1;
+                var startLineIndex = Math.Max(0, currentLineIndex - requestedLineCount);
+
+                DeleteLineImpl(startLineIndex, currentLineIndex - startLineIndex + 1);
+
+                // go the beginning of the line at index 'startLineIndex'
+                // or at the beginning of the last line
+                startLineIndex = Math.Min(startLineIndex, _singleton.GetLogicalLineCount() - 1);
+                var newCurrent = GetBeginningOfNthLinePos(startLineIndex);
+
+                _singleton._current = newCurrent;
+                _singleton.Render();
+            }
+        }
+
         /// <summary>
         /// Deletes the previous word.
         /// </summary>

test/BasicEditingTest.VI.cs

@@ -489,6 +489,46 @@ public void ViDeleteToEndOfBuffer()
                 ));
         }
 
+        [SkippableFact]
+        public void ViDeletePreviousLines()
+        {
+            TestSetup(KeyMode.Vi);
+
+            int continuationPrefixLength = PSConsoleReadLineOptions.DefaultContinuationPrompt.Length;
+
+            Test("\"\n\"", Keys(
+                 _.DQuote, _.Enter,
+                 "one", _.Enter,
+                 "two", _.Enter,
+                 "three", _.Enter,
+                 _.DQuote, _.Escape,
+                 "kl", // go to the 'hree' portion of "three"
+                 "2dk", CheckThat(() => AssertCursorLeftIs(continuationPrefixLength + 0))
+                ));
+        }
+
+        [SkippableFact]
+        public void ViDeletePreviousLines_LastLine()
+        {
+            TestSetup(KeyMode.Vi);
+
+            int continuationPrefixLength = PSConsoleReadLineOptions.DefaultContinuationPrompt.Length;
+
+            Test("\"\none\ntwo\n\"", Keys(
+                 _.DQuote, _.Enter,
+                 "one", _.Enter,
+                 "two", _.Enter,
+                 "three", _.Enter,
+                 _.DQuote, _.Escape,
+                 "dk",
+                 CheckThat(() => AssertCursorLeftIs(continuationPrefixLength + 0)),
+                 CheckThat(() => AssertCursorTopIs(2)),
+                 CheckThat(() => AssertLineIs("\"\none\ntwo")),
+                 // finish the buffer to close the multiline string
+                 _.A, _.Enter, _.DQuote, _.Escape
+                ));
+        }
+
         [SkippableFact]
         public void ViDeleteToEnd()
         {