Apply code review changes

pkg/cmd/pr/shared/finder.go

@@ -212,7 +212,8 @@ func (f *finder) Find(opts FindOptions) (*api.PullRequest, ghrepo.Interface, err
 	}
 
 	var pr *api.PullRequest
-	if f.prNumber > 0 || f.branchName == "" {
+	if f.prNumber > 0 {
+		// If we have a PR number, let's look it up
 		if numberFieldOnly {
 			// avoid hitting the API if we already have all the information
 			return &api.PullRequest{Number: f.prNumber}, f.baseRefRepo, nil
@@ -221,11 +222,16 @@ func (f *finder) Find(opts FindOptions) (*api.PullRequest, ghrepo.Interface, err
 		if err != nil {
 			return pr, f.baseRefRepo, err
 		}
-	} else {
+	} else if prRefs.BaseRepo() != nil && f.branchName != "" {
+		// No PR number, but we have a base repo and branch name.
 		pr, err = findForRefs(httpClient, prRefs, opts.States, fields.ToSlice())
 		if err != nil {
 			return pr, f.baseRefRepo, err
 		}
+	} else {
+		// If we don't have a PR number or a base repo and branch name,
+		// we can't do anything
+		return nil, f.baseRefRepo, &NotFoundError{fmt.Errorf("no pull requests found")}
 	}
 
 	g, _ := errgroup.WithContext(context.Background())

pkg/cmd/pr/shared/finder_test.go

@@ -180,9 +180,7 @@ func TestFind(t *testing.T) {
 					remotePushDefaultFn: stubRemotePushDefault("", nil),
 				},
 			},
-			httpStub: nil,
-			wantPR:   0,
-			wantRepo: "https://github.com/ORIGINOWNER/REPO",
+			wantErr: true,
 		},
 		{
 			name: "number with hash argument",