diff --git a/src/github/copilotPrWatcher.ts b/src/github/copilotPrWatcher.ts
index 1ab4b6739e..63e2d85521 100644
--- a/src/github/copilotPrWatcher.ts
+++ b/src/github/copilotPrWatcher.ts
@@ -48,16 +48,11 @@ export class CopilotStateModel extends Disposable {
 		return `${owner}/${repo}#${prNumber}`;
 	}
 
-	delete(owner: string, repo: string, prNumber: number): void {
-		const key = this.makeKey(owner, repo, prNumber);
-		this.deleteKey(key);
-	}
-
 	deleteKey(key: string): void {
 		if (this._states.has(key)) {
+			const item = this._states.get(key)!;
 			this._states.delete(key);
 			if (this._showNotification.has(key)) {
-				const item = this._states.get(key)!;
 				this._showNotification.delete(key);
 				this._onDidChangeNotifications.fire([item.item]);
 			}
diff --git a/src/test/github/copilotPrWatcher.test.ts b/src/test/github/copilotPrWatcher.test.ts
new file mode 100644
index 0000000000..2625cee2b2
--- /dev/null
+++ b/src/test/github/copilotPrWatcher.test.ts
@@ -0,0 +1,152 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { default as assert } from 'assert';
+import { CopilotStateModel } from '../../github/copilotPrWatcher';
+import { CopilotPRStatus } from '../../common/copilot';
+import { PullRequestModel } from '../../github/pullRequestModel';
+
+describe('Copilot PR watcher', () => {
+
+	describe('CopilotStateModel', () => {
+
+		const createPullRequest = (owner: string, repo: string, number: number): PullRequestModel => {
+			return {
+				number,
+				remote: { owner, repositoryName: repo },
+				author: { login: 'copilot' }
+			} as unknown as PullRequestModel;
+		};
+
+		it('creates consistent keys and reports refresh events', () => {
+			const model = new CopilotStateModel();
+			let refreshEvents = 0;
+			model.onRefresh(() => refreshEvents++);
+
+			assert.strictEqual(model.makeKey('octo', 'repo'), 'octo/repo');
+			assert.strictEqual(model.makeKey('octo', 'repo', 7), 'octo/repo#7');
+
+			model.clear();
+			assert.strictEqual(refreshEvents, 1);
+		});
+
+		it('stores statuses and emits notifications after initialization', () => {
+			const model = new CopilotStateModel();
+			let changeEvents = 0;
+			const notifications: PullRequestModel[][] = [];
+			model.onDidChangeStates(() => changeEvents++);
+			model.onDidChangeNotifications(items => notifications.push(items));
+
+			const pr = createPullRequest('octo', 'repo', 1);
+			model.set([{ pullRequestModel: pr, status: CopilotPRStatus.Started }]);
+
+			assert.strictEqual(model.get('octo', 'repo', 1), CopilotPRStatus.Started);
+			assert.strictEqual(changeEvents, 1);
+			assert.strictEqual(notifications.length, 0);
+			assert.strictEqual(model.notifications.size, 0);
+
+			model.set([{ pullRequestModel: pr, status: CopilotPRStatus.Started }]);
+			assert.strictEqual(changeEvents, 1);
+
+			model.setInitialized();
+			const updated = createPullRequest('octo', 'repo', 1);
+			model.set([{ pullRequestModel: updated, status: CopilotPRStatus.Completed }]);
+
+			assert.strictEqual(model.get('octo', 'repo', 1), CopilotPRStatus.Completed);
+			assert.strictEqual(changeEvents, 2);
+			assert.strictEqual(notifications.length, 1);
+			assert.deepStrictEqual(notifications[0], [updated]);
+			assert.ok(model.notifications.has('octo/repo#1'));
+		});
+
+		it('deletes keys and clears related notifications', () => {
+			const model = new CopilotStateModel();
+			let changeEvents = 0;
+			const notifications: PullRequestModel[][] = [];
+			model.onDidChangeStates(() => changeEvents++);
+			model.onDidChangeNotifications(items => notifications.push(items));
+
+			model.setInitialized();
+			const pr = createPullRequest('octo', 'repo', 42);
+			model.set([{ pullRequestModel: pr, status: CopilotPRStatus.Started }]);
+
+			assert.strictEqual(model.notifications.size, 1);
+			assert.strictEqual(changeEvents, 1);
+
+			model.deleteKey('octo/repo#42');
+			assert.strictEqual(model.get('octo', 'repo', 42), CopilotPRStatus.None);
+			assert.strictEqual(changeEvents, 2);
+			assert.strictEqual(model.notifications.size, 0);
+			assert.strictEqual(notifications.length, 2);
+			assert.deepStrictEqual(notifications[1], [pr]);
+			assert.deepStrictEqual(model.keys(), []);
+		});
+
+		it('clears individual notifications and reports changes', () => {
+			const model = new CopilotStateModel();
+			const notifications: PullRequestModel[][] = [];
+			model.onDidChangeNotifications(items => notifications.push(items));
+
+			model.setInitialized();
+			const pr = createPullRequest('octo', 'repo', 5);
+			model.set([{ pullRequestModel: pr, status: CopilotPRStatus.Started }]);
+			assert.strictEqual(model.notifications.size, 1);
+			assert.strictEqual(notifications.length, 1);
+
+			model.clearNotification('octo', 'repo', 5);
+			assert.strictEqual(model.notifications.size, 0);
+			assert.strictEqual(notifications.length, 2);
+			assert.deepStrictEqual(notifications[1], [pr]);
+
+			model.clearNotification('octo', 'repo', 5);
+			assert.strictEqual(notifications.length, 2);
+		});
+
+		it('supports clearing notifications by repository or entirely', () => {
+			const model = new CopilotStateModel();
+			const notifications: PullRequestModel[][] = [];
+			model.onDidChangeNotifications(items => notifications.push(items));
+
+			assert.strictEqual(model.isInitialized, false);
+			model.setInitialized();
+			assert.strictEqual(model.isInitialized, true);
+
+			const prOne = createPullRequest('octo', 'repo', 1);
+			const prTwo = createPullRequest('octo', 'repo', 2);
+			const prThree = createPullRequest('other', 'repo', 3);
+			model.set([
+				{ pullRequestModel: prOne, status: CopilotPRStatus.Started },
+				{ pullRequestModel: prTwo, status: CopilotPRStatus.Failed },
+				{ pullRequestModel: prThree, status: CopilotPRStatus.Completed }
+			]);
+
+			assert.strictEqual(model.notifications.size, 3);
+			assert.strictEqual(notifications.length, 1);
+			assert.deepStrictEqual(notifications[0], [prOne, prTwo, prThree]);
+			assert.strictEqual(model.getNotificationsCount('octo', 'repo'), 2);
+			assert.deepStrictEqual(model.keys().sort(), ['octo/repo#1', 'octo/repo#2', 'other/repo#3']);
+
+			model.clearAllNotifications('octo', 'repo');
+			assert.strictEqual(model.notifications.size, 1);
+			assert.strictEqual(model.getNotificationsCount('octo', 'repo'), 0);
+			assert.strictEqual(notifications.length, 2);
+			assert.deepStrictEqual(notifications[1], [prOne, prTwo]);
+
+			model.clearAllNotifications();
+			assert.strictEqual(model.notifications.size, 0);
+			assert.strictEqual(notifications.length, 3);
+			assert.deepStrictEqual(notifications[2], [prThree]);
+
+			const counts = model.getCounts('octo', 'repo');
+			assert.deepStrictEqual(counts, { total: 3, inProgress: 1, error: 1 });
+
+			const allStates = model.all;
+			assert.strictEqual(allStates.length, 3);
+			assert.deepStrictEqual(allStates.map(v => v.status).sort(), [CopilotPRStatus.Started, CopilotPRStatus.Completed, CopilotPRStatus.Failed]);
+		});
+	});
+
+
+});
\ No newline at end of file