diff --git a/internal/tools/file_write_branch_test.go b/internal/tools/file_write_branch_test.go
index eeab221..483a1fd 100644
--- a/internal/tools/file_write_branch_test.go
+++ b/internal/tools/file_write_branch_test.go
@@ -90,7 +90,11 @@ func TestFileWriteBranchUsesPutWhenShaProvided(t *testing.T) {
 		"sha":"oldsha","message":"update doc.md"
 	}`))
 	require.NoError(t, err)
-	require.NotNil(t, out)
+
+	var result map[string]any
+	require.NoError(t, json.Unmarshal(out, &result))
+	assert.Equal(t, "feat/existing", result["branch"])
+	assert.Equal(t, "cmt1", result["commit_sha"])
 }
 
 func TestFileWriteBranchUsesDefaultBaseWhenBaseEmpty(t *testing.T) {