feature: copy character from line above/below

docs/overview.md

@@ -3,6 +3,9 @@
 * There are only currently two modes, normal mode and insert mode.
 * Motions have repeat support, `d3w` will delete three words.
 * Insert mode can be entered using `i`, `I`, `a`, `A`, `o`, or `O`.
+  * The following commands are supported in insert mode:
+    * `ctrl-y` to copy the character right above the cursor
+    * `ctrl-e` to copy the character right below the cursor (**disabled by default**, see note 1 below)
 * Replace mode can be entered using `R`
   * Limitations:
     * If repeating with `.` gets a bit confused (e.g. by multiple cursors or when more than one line was typed), please report it with steps to reproduce if you can.
@@ -16,3 +19,13 @@
   * What Doesn't Exist:
     * default buffer doesn't yet save on delete operations.
 * Setting `wrapLeftRightMotion` acts like VIM's whichwrap=h,l,<,>
+
+
+#### Notes
+
+1. To enable the VIM key binding `ctrl-e` to copy the character right below the cursor, please put this in your `keymap.cson`:
+
+```
+'atom-text-editor.vim-mode.insert-mode':
+  'ctrl-e': 'vim-mode:copy-from-line-below'
+```

keymaps/vim-mode.cson

@@ -13,6 +13,9 @@
 'atom-text-editor.vim-mode.insert-mode':
   'ctrl-w': 'editor:delete-to-beginning-of-word'
   'ctrl-u': 'editor:delete-to-beginning-of-line'
+  'ctrl-y': 'vim-mode:copy-from-line-above'
+  # disabled for compatibility with the common binding for going to the end of the line
+  # 'ctrl-e': 'vim-mode:copy-from-line-below'
 
   'ctrl-r a': 'vim-mode:insert-mode-put'
   'ctrl-r b': 'vim-mode:insert-mode-put'

lib/insert-mode.coffee

@@ -0,0 +1,19 @@
+copyCharacterFromAbove = (editor, vimState) ->
+  editor.transact ->
+    for cursor in editor.getCursors()
+      {row, column} = cursor.getScreenPosition()
+      continue if row is 0
+      range = [[row-1, column], [row-1, column+1]]
+      cursor.selection.insertText(editor.getTextInBufferRange(editor.bufferRangeForScreenRange(range)))
+
+copyCharacterFromBelow = (editor, vimState) ->
+  editor.transact ->
+    for cursor in editor.getCursors()
+      {row, column} = cursor.getScreenPosition()
+      range = [[row+1, column], [row+1, column+1]]
+      cursor.selection.insertText(editor.getTextInBufferRange(editor.bufferRangeForScreenRange(range)))
+
+module.exports = {
+  copyCharacterFromAbove,
+  copyCharacterFromBelow
+}

lib/vim-state.coffee

@@ -7,6 +7,7 @@ settings = require './settings'
 Operators = require './operators/index'
 Prefixes = require './prefixes'
 Motions = require './motions/index'
+InsertMode = require './insert-mode'
 
 TextObjects = require './text-objects'
 Utils = require './utils'
@@ -73,6 +74,8 @@ class VimState
       'undo': (e) => @undo(e)
       'replace-mode-backspace': => @replaceModeUndo()
       'insert-mode-put': (e) => @insertRegister(@registerName(e))
+      'copy-from-line-above': => InsertMode.copyCharacterFromAbove(@editor, this)
+      'copy-from-line-below': => InsertMode.copyCharacterFromBelow(@editor, this)
 
     @registerOperationCommands
       'activate-insert-mode': => new Operators.Insert(@editor, this)

spec/insert-mode-spec.coffee

@@ -0,0 +1,73 @@
+helpers = require './spec-helper'
+
+describe "Insert mode commands", ->
+  [editor, editorElement, vimState] = []
+
+  beforeEach ->
+    vimMode = atom.packages.loadPackage('vim-mode')
+    vimMode.activateResources()
+
+    helpers.getEditorElement (element) ->
+      editorElement = element
+      editor = editorElement.getModel()
+      vimState = editorElement.vimState
+      vimState.activateNormalMode()
+      vimState.resetNormalMode()
+
+  keydown = (key, options={}) ->
+    options.element ?= editorElement
+    helpers.keydown(key, options)
+
+  describe "Copy from line above/below", ->
+    beforeEach ->
+      editor.setText("12345\n\nabcd\nefghi")
+      editor.setCursorBufferPosition([1, 0])
+      editor.addCursorAtBufferPosition([3, 0])
+      keydown 'i'
+
+    describe "the ctrl-y command", ->
+      it "copies from the line above", ->
+        keydown 'y', ctrl: true
+        expect(editor.getText()).toBe '12345\n1\nabcd\naefghi'
+
+        editor.insertText ' '
+        keydown 'y', ctrl: true
+        expect(editor.getText()).toBe '12345\n1 3\nabcd\na cefghi'
+
+      it "does nothing if there's nothing above the cursor", ->
+        editor.insertText 'fill'
+        keydown 'y', ctrl: true
+        expect(editor.getText()).toBe '12345\nfill5\nabcd\nfillefghi'
+
+        keydown 'y', ctrl: true
+        expect(editor.getText()).toBe '12345\nfill5\nabcd\nfillefghi'
+
+      it "does nothing on the first line", ->
+        editor.setCursorBufferPosition([0, 2])
+        editor.addCursorAtBufferPosition([3, 2])
+        editor.insertText 'a'
+        expect(editor.getText()).toBe '12a345\n\nabcd\nefaghi'
+        keydown 'y', ctrl: true
+        expect(editor.getText()).toBe '12a345\n\nabcd\nefadghi'
+
+    describe "the ctrl-e command", ->
+      beforeEach ->
+        atom.keymaps.add "test",
+          'atom-text-editor.vim-mode.insert-mode':
+            'ctrl-e': 'vim-mode:copy-from-line-below'
+
+      it "copies from the line below", ->
+        keydown 'e', ctrl: true
+        expect(editor.getText()).toBe '12345\na\nabcd\nefghi'
+
+        editor.insertText ' '
+        keydown 'e', ctrl: true
+        expect(editor.getText()).toBe '12345\na c\nabcd\n efghi'
+
+      it "does nothing if there's nothing below the cursor", ->
+        editor.insertText 'foo'
+        keydown 'e', ctrl: true
+        expect(editor.getText()).toBe '12345\nfood\nabcd\nfooefghi'
+
+        keydown 'e', ctrl: true
+        expect(editor.getText()).toBe '12345\nfood\nabcd\nfooefghi'