How to filter by a file extension in a graphql query

Question

I would like to query the content of markdown files inside a docs folder in a repository. I am using gatsby-source-graphql and GitHub v4 API.

Thus far I've managed to get file contents with this code:

{
  github {
    search(first: 1, type: REPOSITORY, query: "repo:kalessil/phpinspectionsea") {
      edges {
        node {
          ... on GitHub_Repository {
            folder: object(expression: "master:docs/") {
              ... on GitHub_Tree {
                entries {
                  oid
                  object {
                    ... on GitHub_Blob {
                      text
                    }
                  }
                  name
                }
              }
            }
          }
        }
      }
    }
  }
}

The problem is that any type of file might end up inside the directory, such as txt and will require additional work to filter out.

Is there a way to query files only with md extension inside the docs/ directory?

EDIT:

It is possible to accomplish in three steps. First by querying all files, filtering and then querying individual files:

{
  github {
    files: search(first: 1, type: REPOSITORY, query: "repo:kalessil/phpinspectionsea") {
      edges {
        node {
          ... on GitHub_Repository {
            object(expression: "master:docs/") {
              ... on GitHub_Tree {
                entries {
                  name
                }
              }
            }
          }
        }
      }
    }
    content: search(first: 1, type: REPOSITORY, query: "repo:kalessil/phpinspectionsea") {
      edges {
        node {
          ... on GitHub_Repository {
            object(expression: "master:docs/DEVELOPERS.md") {
              ... on GitHub_Blob {
                text
              }
            }
          }
        }
      }
    }
  }
}

Maybe there is a better way?

EDIT2:

I've refactored the code according to @robinmentral (thank you):

{
  github {
    files: repository(owner: "kalessil", name: "phpinspectionsea") {
      ... on GitHub_Repository {
        object(expression: "master:docs/") {
          ... on GitHub_Tree {
            entries {
              name
            }
          }
        }
      }
    }
    content: repository(owner: "kalessil", name: "phpinspectionsea") {
      ... on GitHub_Repository {
        object(expression: "master:docs/DEVELOPERS.md") {
          ... on GitHub_Blob {
            text
          }
        }
      }
    }
  }
}

But it still requires filtering on JavaScript side. As I need to get all the names first, filter out by extension and query only those files directly.

This is actually the right way to do in gatsby-source-graphql; for anyone who encounters this in the future check out their example project.

Now I'm just curious if it's possible to combine all these operations in one.

Answer 1

Following up on my comment: if you want to query the contents of a specific file (like in your example), you could use this cleaner query:

{
  repository(owner: "kalessil", name: "phpinspectionsea") {
    ... on Github_Repository {
      object(expression: "master:docs/DEVELOPERS.md") {
        ... on Github_Blob {
          text
        }
      }
    }
  }
}