Support backspace in insert mode.

css/base.css

@@ -3,6 +3,10 @@
     margin: 20px auto;
     font-family: 'Arial', sans-serif;
 }
+.vimulator input {
+    position: absolute;
+    left: -9999px;
+}
 .vimulator pre {
     position: relative;
     z-index: 2;

js/base.js

@@ -36,9 +36,15 @@
     Vimulator.Base.prototype.bindKeyListeners = function () {
         var vim = this;
 
+        this.input = $('<input type="text">').appendTo(this.container)
+                                             .focus()
+                                             .blur(function () {
+                                                 $(this).focus();
+                                             });
+
         // Use keyup for special characters like escape
         $(window).keyup(function (e) {
-            if (e.keyCode === 27) {
+            if (e.keyCode < 32) {
                 vim.keyPress(e.keyCode);
                 return false;
             }
@@ -136,13 +142,35 @@
         return this.lines[this.cursor.row];
     };
 
-    Vimulator.Base.prototype.appendText = function (text) {
-        line = this.currentLine();
-        this.lines[this.cursor.row] =
-                line.substr(0, this.cursor.col) +
-                text +
-                line.substr(this.cursor.col);
-        this.cursor.col += text.length;
+    Vimulator.Base.prototype.appendChr = function (chr) {
+        var line;
+
+        if (chr === Vimulator.Utils.Keys.BACKSPACE) {
+            this.removeChr();
+        } else {
+            line = this.currentLine();
+            this.lines[this.cursor.row] =
+                    line.substr(0, this.cursor.col) +
+                    chr +
+                    line.substr(this.cursor.col);
+            this.cursor.col += 1;
+        }
+    };
+
+    Vimulator.Base.prototype.removeChr = function () {
+        var line = this.currentLine();
+
+        if (this.cursor.col === 0 && this.cursor.row > 0) {
+            this.moveCursorRelative(-1, '$');
+            this.cursor.col += 1; //FIXME
+            this.lines[this.cursor.row] += line;
+            this.removeRows(this.cursor.row + 1, this.cursor.row + 2);
+        } else if (this.cursor.col > 0) {
+            this.lines[this.cursor.row] =
+                    line.substr(0, this.cursor.col - 1) +
+                    line.substr(this.cursor.col);
+            this.cursor.col -= 1;
+        }
     };
 
     Vimulator.Base.prototype.insertRowBelow = function (text, index) {

js/insert_mode.js

@@ -28,7 +28,7 @@
             return op;
         } else {
             this.vim.registers["."] += key;
-            this.vim.appendText(key);
+            this.vim.appendChr(key);
         }
     };
 }());

js/utils.js

@@ -4,8 +4,9 @@
     Vimulator.Utils = {};
 
     Vimulator.Utils.Keys = K = {
-        ESC: '\u001B',
-        RETURN: '\u000D'
+        BACKSPACE:  '\u0008',
+        RETURN:     '\u000D',
+        ESC:        '\u001B'
     };
 
     Vimulator.Utils.pluralize = function (count, word) {

tests/acceptance/insertion.js

@@ -95,3 +95,26 @@ describe("Substituting lines with S", function () {
         expect(currentText()).toBe("1 and 2\nThird\nFourth");
     });
 });
+
+describe("Deleting characters with backspace", function () {
+    it("deletes a character before the cursor", function () {
+        reset("Hello world!!1");
+        pressKeys("A" + BACKSPACE + BACKSPACE + ESC);
+        expect(currentText()).toBe("Hello world!");
+        expect(cursorPosition()).toEqual({row: 0, col: 11});
+    });
+
+    it("deletes line breaks", function () {
+        reset("First line\nSecond line\nThird line");
+        pressKeys("ja" + BACKSPACE + BACKSPACE + ESC);
+        expect(currentText()).toBe("First lineecond line\nThird line");
+        expect(cursorPosition()).toEqual({row: 0, col: 9});
+    });
+
+    it("does not delete beyond the end of the document", function () {
+        reset("Hello world");
+        pressKeys("gI" + BACKSPACE + BACKSPACE + ESC);
+        expect(currentText()).toBe("Hello world");
+        expect(cursorPosition()).toEqual({row: 0, col: 0});
+    });
+});

tests/acceptance/repeat.js

@@ -23,6 +23,11 @@ describe("Repeating the last command with .", function () {
         expect(currentText()).toBe("Here ore some words, they ore all here");
     });
 
+    it("repeats backspaces", function () {
+        pressKeys("ea" + BACKSPACE + ESC + "e.e.");
+        expect(currentText()).toBe("Her ar som words, they are all here");
+    });
+
     it("does not repeat motions", function () {
         pressKeys("3l");
         expect(cursorPosition()).toEqual({row: 0, col: 3});

tests/helpers.js

@@ -1,5 +1,6 @@
 ESC = '\u001B';
 RETURN = '\u000D';
+BACKSPACE = '\u0008';
 
 function pressKeys(keys) {
     jQuery.each(keys.split(''), function (i, key) {

tests/unit/insert_mode.js

@@ -13,7 +13,7 @@ describe("InsertMode", function () {
             vim = jasmine.createSpyObj("vim", [
                 "moveCursorRelative",
                 "setMode",
-                "appendText"
+                "appendChr"
             ]);
             vim.registers = {};
             im = new Vimulator.InsertMode(vim);
@@ -33,7 +33,7 @@ describe("InsertMode", function () {
             for (i = 0; i < chars.length; i +=1) {
                 chr = chars[i];
                 im.keyPress(chr);
-                expect(vim.appendText).toHaveBeenCalledWith(chr);
+                expect(vim.appendChr).toHaveBeenCalledWith(chr);
             }
         });