We should skip the same URL

src/routing/history/StateHistory.ts

@@ -53,7 +53,12 @@ export class StateHistory implements HistoryInterface {
 	}
 
 	public set(path: string) {
-		this._window.history.pushState({}, '', this.prefix(stripBase(this._base, path)));
+		const value = stripBase(this._base, path);
+		if (this._current === value) {
+			return;
+		}
+
+		this._window.history.pushState({}, '', this.prefix(value));
 		this._onChange();
 	}
 
@@ -63,11 +68,8 @@ export class StateHistory implements HistoryInterface {
 
 	private _onChange = () => {
 		const pathName = this._window.location.pathname.replace(/\/$/, '');
-		const value = stripBase(this._base, pathName + this._window.location.search);
-		if (this._current === value) {
-			return;
-		}
-		this._current = value;
+		this._current = stripBase(this._base, pathName + this._window.location.search);
+
 		this._onChangeFunction(this._current);
 	};
 }

tests/routing/unit/history/StateHistory.ts

@@ -57,6 +57,15 @@ describe('StateHistory', () => {
 		assert.equal(sandbox.contentWindow!.location.pathname, '/foo');
 	});
 
+	it('update path, does not update path if path is set to the current value', () => {
+		const history = new StateHistory({ onChange, window: sandbox.contentWindow! });
+		const beforeLength = sandbox.contentWindow!.history.length;
+		history.set('/bar');
+		history.set('/bar');
+		const afterLength = sandbox.contentWindow!.history.length;
+		assert.equal(afterLength - beforeLength, 1);
+	});
+
 	it('update path, adds leading slash if necessary', () => {
 		const history = new StateHistory({ onChange, window: sandbox.contentWindow! });
 		history.set('foo');