samrae7/gatsby-remark-repro

Reproduction of this issue: gatsbyjs/gatsby#18312

1. Clone this repo and

   cd gatsby-remark-repro/
   npm install
   gatsby develop

2. Go to _http://localhost:8000/___graphqland send the following gql request:

query searchDataQuery {
  allMarkdownRemark {
    edges {
      node {
        id
        excerpt(pruneLength: 60, format: MARKDOWN)
      }
    }
  }
}

Notice that the excerpt for the md file without the exerpt seperator is returned as empty string. Seeing as the pruneLength works when there is no exerpt seperator option, it seems reasonable that it should fall back to the pruneLength.