delete matching brackets when the opening bracket is deleted

src/matching/matcher.ts

@@ -1,4 +1,5 @@
-import { Position } from './../motion/position';
+import { Position, PositionDiff } from './../motion/position';
+import * as vscode from 'vscode';
 
 /**
  * PairMatcher finds the position matching the given character, respecting nested
@@ -62,4 +63,29 @@ export class PairMatcher {
     // TODO(bell)
     return undefined;
   }
+
+  /**
+   * Given a current position, find an immediate following bracket and return the range. If
+   * no matching bracket is found immediately following the opening bracket, return undefined.
+   */
+  static immediateMatchingBracket(currentPosition: Position): vscode.Range | undefined {
+    let deleteRange = new vscode.Range(currentPosition, currentPosition.getLeftThroughLineBreaks());
+    let deleteText = vscode.window.activeTextEditor.document.getText(deleteRange);
+    let matchRange: vscode.Range | undefined;
+    let isNextMatch = false;
+
+    if ("{[(<".indexOf(deleteText) > -1) {
+      let matchPosition = currentPosition.add(new PositionDiff(0, 1));
+      if (matchPosition) {
+        matchRange = new vscode.Range(matchPosition, matchPosition.getLeftThroughLineBreaks());
+        isNextMatch = vscode.window.activeTextEditor.document.getText(matchRange) === PairMatcher.pairings[deleteText].match;
+      }
+    }
+
+    if (isNextMatch && matchRange) {
+      return matchRange;
+    }
+
+    return undefined;
+  }
 }

src/mode/modeHandler.ts

@@ -1291,6 +1291,8 @@ export class ModeHandler implements vscode.Disposable {
                 break;
 
               case "deleteText":
+                let matchRange = PairMatcher.immediateMatchingBracket(command.position);
+                if (matchRange) { edit.delete(matchRange); }
                 edit.delete(new vscode.Range(command.position, command.position.getLeftThroughLineBreaks()));
                 break;
 

test/mode/modeInsert.test.ts

@@ -174,6 +174,24 @@ suite("Mode Insert", () => {
         assertEqualLines(["  "]);
     });
 
+    test("will remove closing bracket", async() => {
+        await modeHandler.handleMultipleKeyEvents([
+            'i',
+            '(',
+            '<Esc>'
+        ]);
+
+        assertEqualLines(["()"]);
+
+        await modeHandler.handleMultipleKeyEvents([
+            'a',
+            '<BS>',
+            '<Esc>'
+        ]);
+
+        assertEqualLines([""]);
+    });
+
     newTest({
       title: "Can perform <ctrl+o> to exit and perform one command in normal",
       start: ['testtest|'],