Panic if tracking ref can't be reconstructed

git/objects.go

@@ -1,7 +1,6 @@
 package git
 
 import (
-	"fmt"
 	"net/url"
 	"strings"
 )
@@ -65,17 +64,6 @@ func (r TrackingRef) String() string {
 	return "refs/remotes/" + r.RemoteName + "/" + r.BranchName
 }
 
-func ParseTrackingRef(text string) (TrackingRef, error) {
-	parts := strings.SplitN(string(text), "/", 4)
-	if len(parts) != 4 {
-		return TrackingRef{}, fmt.Errorf("invalid tracking ref: %s", text)
-	}
-	return TrackingRef{
-		RemoteName: parts[2],
-		BranchName: parts[3],
-	}, nil
-}
-
 type Commit struct {
 	Sha   string
 	Title string

pkg/cmd/pr/create/create.go

@@ -555,10 +555,7 @@ func determineTrackingBranch(gitClient *git.Client, remotes ghContext.Remotes, l
 				continue
 			}
 			// Otherwise we can parse the returned ref into a tracking ref and return that
-			trackingRef, err := git.ParseTrackingRef(r.Name)
-			if err != nil {
-				return nil
-			}
+			trackingRef := mustParseTrackingRef(r.Name)
 			return &trackingRef
 		}
 	}
@@ -566,6 +563,17 @@ func determineTrackingBranch(gitClient *git.Client, remotes ghContext.Remotes, l
 	return nil
 }
 
+func mustParseTrackingRef(text string) git.TrackingRef {
+	parts := strings.SplitN(string(text), "/", 4)
+	if len(parts) != 4 {
+		panic(fmt.Errorf("invalid tracking ref: %s", text))
+	}
+	return git.TrackingRef{
+		RemoteName: parts[2],
+		BranchName: parts[3],
+	}
+}
+
 func NewIssueState(ctx CreateContext, opts CreateOptions) (*shared.IssueMetadataState, error) {
 	var milestoneTitles []string
 	if opts.Milestone != "" {