Cache copilot timeline events (#7973)

Author: alexr00

src/github/copilotPrWatcher.ts

@@ -270,7 +270,7 @@ export class CopilotPRWatcher extends Disposable {
 	private async _updateSingleState(pr: PullRequestModel): Promise<void> {
 		const changes: { pullRequestModel: PullRequestModel, status: CopilotPRStatus }[] = [];
 
-		const copilotEvents = await pr.getCopilotTimelineEvents(pr);
+		const copilotEvents = await pr.getCopilotTimelineEvents(pr, false, !this._model.isInitialized);
 		let latestEvent = copilotEventToStatus(copilotEvents[copilotEvents.length - 1]);
 		if (latestEvent === CopilotPRStatus.None) {
 			if (!COPILOT_ACCOUNTS[pr.author.login]) {
@@ -315,7 +315,7 @@ export class CopilotPRWatcher extends Disposable {
 
 					for (const pr of items) {
 						unseenKeys.delete(this._model.makeKey(pr.remote.owner, pr.remote.repositoryName, pr.number));
-						const copilotEvents = await pr.getCopilotTimelineEvents(pr);
+						const copilotEvents = await pr.getCopilotTimelineEvents(pr, false, !this._model.isInitialized);
 						let latestEvent = copilotEventToStatus(copilotEvents[copilotEvents.length - 1]);
 						if (latestEvent === CopilotPRStatus.None) {
 							if (!COPILOT_ACCOUNTS[pr.author.login]) {

src/github/issueModel.ts

@@ -68,6 +68,7 @@ export class IssueModel<TItem extends Issue = Issue> extends Disposable {
 	private _lastCheckedForUpdatesAt?: Date;
 
 	private _timelineEvents: readonly TimelineEvent[] | undefined;
+	private _copilotTimelineEvents: TimelineEvent[] | undefined;
 
 	protected _onDidChange = this._register(new vscode.EventEmitter<IssueChangeEvent>());
 	public onDidChange = this._onDidChange.event;
@@ -514,13 +515,19 @@ export class IssueModel<TItem extends Issue = Issue> extends Disposable {
 	/**
 	 * TODO: @alexr00 we should delete this https://github.com/microsoft/vscode-pull-request-github/issues/6965
 	 */
-	async getCopilotTimelineEvents(issueModel: IssueModel, skipMerge: boolean = false): Promise<TimelineEvent[]> {
+	async getCopilotTimelineEvents(issueModel: IssueModel, skipMerge: boolean = false, useCache: boolean = false): Promise<TimelineEvent[]> {
 		if (!COPILOT_ACCOUNTS[issueModel.author.login]) {
 			return [];
 		}
 
 		Logger.debug(`Fetch Copilot timeline events of issue #${issueModel.number} - enter`, GitHubRepository.ID);
 
+		if (useCache && this._copilotTimelineEvents) {
+			Logger.debug(`Fetch Copilot timeline events of issue #${issueModel.number} (used cache) - exit`, GitHubRepository.ID);
+
+			return this._copilotTimelineEvents;
+		}
+
 		const { octokit, remote } = await this.githubRepository.ensure();
 		try {
 			const timeline = await restPaginate<typeof octokit.api.issues.listEventsForTimeline, OctokitCommon.ListEventsForTimelineResponse>(octokit.api.issues.listEventsForTimeline, {
@@ -531,6 +538,7 @@ export class IssueModel<TItem extends Issue = Issue> extends Disposable {
 			});
 
 			const timelineEvents = parseSelectRestTimelineEvents(issueModel, timeline);
+			this._copilotTimelineEvents = timelineEvents;
 			if (timelineEvents.length === 0) {
 				return [];
 			}