adds merge state status

api/client.go

@@ -239,6 +239,7 @@ func (c Client) GraphQL(hostname string, query string, variables map[string]inte
 	}
 
 	req.Header.Set("Content-Type", "application/json; charset=utf-8")
+	req.Header.Set("Accept", "application/vnd.github.merge-info-preview+json")
 
 	resp, err := c.http.Do(req)
 	if err != nil {

api/queries_pr.go

@@ -38,6 +38,7 @@ type PullRequest struct {
 	HeadRefName string
 	Body        string
 	Mergeable   string
+	MergeStateStatus   string
 
 	Author struct {
 		Login string
@@ -353,6 +354,7 @@ func PullRequests(client *Client, repo ghrepo.Interface, currentPRNumber int, cu
 		state
 		url
 		headRefName
+		mergeStateStatus
 		headRepositoryOwner {
 			login
 		}

pkg/cmd/pr/status/status.go

@@ -227,6 +227,16 @@ func printPrs(io *iostreams.IOStreams, totalCount int, prs ...api.PullRequest) {
 			} else if reviews.Approved {
 				fmt.Fprint(w, cs.Green("✓ Approved"))
 			}
+
+			// add padding between reviews & merge status
+			fmt.Fprint(w, " ")
+
+			if pr.MergeStateStatus == "BEHIND" {
+				fmt.Fprint(w, cs.Yellow("- Not up to date"))
+			} else {
+				fmt.Fprint(w, cs.Green("✓ Up to date"))
+			}
+
 		} else {
 			fmt.Fprintf(w, " - %s", shared.StateTitleWithColor(cs, pr))
 		}