Handle failed merge when branch gets updated

1 files changed, 22 insertions, 0 deletions

diff --git a/internal/testhelper/commit.go b/internal/testhelper/commit.go
new file mode 100644
index 000000000..5d3cca8da
--- /dev/null
+++ b/internal/testhelper/commit.go
@@ -0,0 +1,22 @@
+package testhelper
+
+import (
+	"strings"
+	"testing"
+)
+
+// CreateCommit makes a new empty commit and updates the named branch to point to it.
+func CreateCommit(t *testing.T, repoPath string, branchName string) string {
+	// The ID of an arbitrary commit known to exist in the test repository.
+	parentID := "1a0b36b3cdad1d2ee32457c102a8c0b7056fa863"
+
+	// Use 'commit-tree' instead of 'commit' because we are in a bare
+	// repository. What we do here is the same as "commit -m message
+	// --allow-empty".
+	commitArgs := []string{"-C", repoPath, "commit-tree", "-m", "message", "-p", parentID, parentID + "^{tree}"}
+	newCommit := MustRunCommand(t, nil, "git", commitArgs...)
+	newCommitID := strings.TrimSpace(string(newCommit))
+
+	MustRunCommand(t, nil, "git", "-C", repoPath, "update-ref", "refs/heads/"+branchName, newCommitID)
+	return newCommitID
+}