refactor: dupe cursors

src/mode/modeHandler.ts

@@ -642,30 +642,6 @@ export class ModeHandler implements vscode.Disposable {
       this.vimState.lastVisualSelectionEnd = this.vimState.cursorStopPosition;
     }
 
-    // Make sure no two cursors are at the same location.
-    // This is a consequence of the fact that allCursors is not a Set.
-
-    // TODO: It should be a set.
-
-    const resultingList: Range[] = [];
-
-    for (const cursor of vimState.cursors) {
-      let shouldAddToList = true;
-
-      for (const alreadyAddedCursor of resultingList) {
-        if (cursor.equals(alreadyAddedCursor)) {
-          shouldAddToList = false;
-          break;
-        }
-      }
-
-      if (shouldAddToList) {
-        resultingList.push(cursor);
-      }
-    }
-
-    vimState.cursors = resultingList;
-
     return vimState;
   }
 

src/state/vimState.ts

@@ -152,13 +152,17 @@ export class VimState implements vscode.Disposable {
     return this._cursors;
   }
   public set cursors(value: Range[]) {
+    const map = new Map<string, Range>();
     for (const cursor of value) {
       if (!cursor.isValid(this.editor)) {
         this.logger.warn(`invalid cursor position. ${cursor.toString()}.`);
       }
+
+      // use a map to ensure no two cursors are at the same location.
+      map.set(cursor.toString(), cursor);
     }
 
-    this._cursors = value;
+    this._cursors = Array.from(map.values());
     this.isMultiCursor = this._cursors.length > 1;
   }
 

test/state/vimState.test.ts

@@ -0,0 +1,51 @@
+import * as assert from 'assert';
+import * as vscode from 'vscode';
+import { Position } from '../../src/common/motion/position';
+import { Range } from '../../src/common/motion/range';
+import { VimState } from '../../src/state/vimState';
+import { setupWorkspace, cleanUpWorkspace } from '../testUtils';
+
+suite('VimState', () => {
+  setup(async () => {
+    await setupWorkspace();
+  });
+
+  teardown(cleanUpWorkspace);
+
+  test('de-dupes cursors', () => {
+    // setup
+    const vimState = new VimState(vscode.window.activeTextEditor!);
+    const cursorStart = new Position(0, 0);
+    const cursorStop = new Position(0, 1);
+    const initialCursors = [
+      new Range(cursorStart, cursorStop),
+      new Range(cursorStart, cursorStop)
+    ];
+
+    // test
+    vimState.cursors = initialCursors;
+
+    // assert
+    assert.equal(vimState.cursors.length, 1);
+  });
+
+  test('cursorStart/cursorStop should be first cursor in cursors', () => {
+    // setup
+    const vimState = new VimState(vscode.window.activeTextEditor!);
+    const cursorStart = new Position(0, 0);
+    const cursorStop = new Position(0, 1);
+    const initialCursors = [
+      new Range(cursorStart, cursorStop),
+      new Range(new Position(1, 0), new Position(1, 1))
+    ];
+
+    // test
+    vimState.cursors = initialCursors;
+
+    // assert
+    assert.equal(vimState.cursors.length, 2);
+    assert.equal(vimState.isMultiCursor, true);
+    vimState.cursorStartPosition = cursorStart;
+    vimState.cursorStopPosition = cursorStop;
+  });
+});