Allow PRs with deleted head to show in view (#6101)

* Allow PRs with deleted head to show in view
This is to better support the new revert feature

* Fix test

package.json

@@ -747,6 +747,7 @@
 				"command": "pr.pick",
 				"title": "%command.pr.pick.title%",
 				"category": "%command.pull.request.category%",
+				"enablement": "viewItem =~ /hasHeadRef/",
 				"icon": "$(arrow-right)"
 			},
 			{

src/github/folderRepositoryManager.ts

@@ -2047,11 +2047,7 @@ export class FolderRepositoryManager implements vscode.Disposable {
 		if (githubRepo) {
 			const pr = await githubRepo.getPullRequest(pullRequestNumber);
 			Logger.appendLine(`Found GitHub pr repo for pr #${pullRequestNumber}: ${pr ? 'yes' : 'no'}`, this.id);
-			if (pr) {
-				if (await githubRepo.hasBranch(pr.base.name)) {
-					return pr;
-				}
-			}
+			return pr;
 		}
 		return undefined;
 	}

src/github/githubRepository.ts

@@ -912,8 +912,8 @@ export class GitHubRepository implements vscode.Disposable {
 
 			const pullRequests = pullRequestResponses
 				.map(response => {
-					if (!response.repository?.pullRequest.headRef) {
-						Logger.appendLine('The remote branch for this PR was already deleted.', this.id);
+					if (!response.repository) {
+						Logger.appendLine('Pull request doesn\'t appear to exist.', this.id);
 						return null;
 					}
 
@@ -1542,7 +1542,7 @@ export class GitHubRepository implements vscode.Disposable {
 			};
 
 		let reviewRequirement: PullRequestReviewRequirement | null = null;
-		const rule = result.data.repository.pullRequest.baseRef.refUpdateRule;
+		const rule = result.data.repository.pullRequest.baseRef?.refUpdateRule;
 		if (rule) {
 			const prUrl = result.data.repository.pullRequest.url;
 

src/github/graphql.ts

@@ -903,7 +903,7 @@ export interface GetChecksResponse {
 					requiresCodeOwnerReviews: boolean;
 					viewerCanPush: boolean;
 				} | null;
-			};
+			} | null;
 			commits: {
 				nodes: {
 					commit: {

src/test/view/prsTree.test.ts

@@ -210,14 +210,14 @@ describe('GitHub Pull Requests view', function () {
 			assert.strictEqual(localItem0.tooltip, 'zero by @me');
 			assert.strictEqual(localItem0.description, 'by @me');
 			assert.strictEqual(localItem0.collapsibleState, vscode.TreeItemCollapsibleState.Collapsed);
-			assert.strictEqual(localItem0.contextValue, 'pullrequest:local:nonactive');
+			assert.strictEqual(localItem0.contextValue, 'pullrequest:local:nonactive:hasHeadRef');
 			assert.deepStrictEqual(localItem0.iconPath!.toString(), 'https://avatars.com/me.jpg');
 
 			assert.strictEqual(localItem1.label, '✓ one');
 			assert.strictEqual(localItem1.tooltip, 'Current Branch * one by @you');
 			assert.strictEqual(localItem1.description, 'by @you');
 			assert.strictEqual(localItem1.collapsibleState, vscode.TreeItemCollapsibleState.Collapsed);
-			assert.strictEqual(localItem1.contextValue, 'pullrequest:local:active');
+			assert.strictEqual(localItem1.contextValue, 'pullrequest:local:active:hasHeadRef');
 			assert.deepStrictEqual(localItem1.iconPath!.toString(), 'https://avatars.com/you.jpg');
 		});
 	});

src/view/reviewManager.ts

@@ -389,9 +389,9 @@ export class ReviewManager {
 
 			const { owner, repositoryName } = metadata;
 			Logger.appendLine('Resolving pull request', this.id);
-			const pr = await this._folderRepoManager.resolvePullRequest(owner, repositoryName, metadata.prNumber);
+			let pr = await this._folderRepoManager.resolvePullRequest(owner, repositoryName, metadata.prNumber);
 
-			if (!pr || !pr.isResolved()) {
+			if (!pr || !pr.isResolved() || !(await pr.githubRepository.hasBranch(pr.base.name))) {
 				await this.clear(true);
 				this._prNumber = undefined;
 				Logger.appendLine('This PR is no longer valid', this.id);
@@ -954,7 +954,7 @@ export class ReviewManager {
 				vscode.window.showErrorMessage(formatError(e));
 			}
 			// todo, we should try to recover, for example, git checkout succeeds but set config fails.
-			if (this._folderRepoManager.activePullRequest) {
+			if (this._folderRepoManager.activePullRequest?.number === pr.number) {
 				this.setStatusForPr(this._folderRepoManager.activePullRequest);
 			} else {
 				this.statusBarItem.hide();

src/view/treeNodes/descriptionNode.ts

@@ -44,6 +44,7 @@ export class DescriptionNode extends TreeNode implements vscode.TreeItem {
 		this.contextValue = 'description' +
 			(currentBranchIsForThisPR ? ':active' : ':nonactive') +
 			(this.pullRequestModel.hasChangesSinceLastReview ? ':hasChangesSinceReview' : '') +
-			(this.pullRequestModel.showChangesSinceReview ? ':showingChangesSinceReview' : ':showingAllChanges');
+			(this.pullRequestModel.showChangesSinceReview ? ':showingChangesSinceReview' : ':showingAllChanges') +
+			(this.pullRequestModel.item.isRemoteHeadDeleted ? '' : ':hasHeadRef');
 	}
 }

src/view/treeNodes/pullRequestNode.ts

@@ -313,7 +313,8 @@ export class PRNode extends TreeNode implements vscode.CommentingRangeProvider2
 				'pullrequest' +
 				(this._isLocal ? ':local' : '') +
 				(currentBranchIsForThisPR ? ':active' : ':nonactive') +
-				(hasNotification ? ':notification' : ''),
+				(hasNotification ? ':notification' : '') +
+				(this.pullRequestModel.item.isRemoteHeadDeleted ? '' : ':hasHeadRef'),
 			iconPath: (await DataUri.avatarCirclesAsImageDataUris(this._folderReposManager.context, [this.pullRequestModel.author], 16, 16))[0]
 				?? new vscode.ThemeIcon('github'),
 			accessibilityInformation: {