Schema customization - Support for multiple source in gatsby

[sonapraneeth-a]

I've defined types and interfaces in one gatsby-package source-core[1] and in other package source-mdx[2], I'm populating the content for the schema defined in source-core

[1]

exports.createSchemaCustomization = ({ actions, schema }) => {
    actions.createTypes(`
    interface ICollectionItem @nodeInterface {
      id: ID!
      title: String!
      name: String!
      slug: String!
      body: String!
      excerpt: String!
      tableOfContents: JSON
      isDraft: Boolean!
      showTOC: Boolean!
      tags: [String!]!
      categories: [String!]!
      publishedTime: Date! @dateformat
      lastModifiedTime: Date! @dateformat
    }
    type CollectionItem implements ICollectionItem & Node @dontInfer {
      id: ID!
      title: String!
      name: String!
      slug: String!
      body: String!
      excerpt: String!
      tableOfContents: JSON
      isDraft: Boolean!
      showTOC: Boolean!
      tags: [String!]!
      categories: [String!]!
      timeToRead: Int
      publishedTime: Date! @dateformat
      lastModifiedTime: Date! @dateformat
    }
  `);
};

[2]

exports.createSchemaCustomization = ({ actions, schema }) => {
    actions.createTypes(
        schema.buildObjectType({
            name: `CollectionItem`,
            fields: {
                body: {
                    type: `String!`,
                    resolve: mdxResolverPassthrough(`body`),
                },
                excerpt: {
                    type: `String!`,
                    args: {
                        pruneLength: {
                            type: `Int`,
                            defaultValue: 140,
                        },
                    },
                    resolve: mdxResolverPassthrough(`excerpt`),
                },
                tableOfContents: {
                    type: `JSON`,
                    args: {
                        maxDepth: {
                            type: `Int`,
                            defaultValue: 6,
                        },
                    },
                    resolve: mdxResolverPassthrough(`tableOfContents`),
                },
                timeToRead: {
                    type: `Int`,
                    resolve: mdxResolverPassthrough(`timeToRead`),
                },
            },
        }),
    );
};

Repo: https://github.com/sonapraneeth-a/multiple-source-gatsby

Instructions for reproduction to see the attached error:

warn Plugin `@sonapraneeth/gatsby-source-mdx` has customized the GraphQL type `CollectionItem`, which has already been defined by the plugin `@sonapraneeth/gatsby-source-core`. This could potentially cause conflicts.
warn Plugin `@sonapraneeth/gatsby-source-core` has customized the GraphQL type `CollectionItem`, which has already been defined by the plugin `@sonapraneeth/gatsby-source-mdx`. This could potentially cause conflicts.
warn Plugin `@sonapraneeth/gatsby-source-mdx` has customized the GraphQL type `CollectionItem`, which has already been defined by the plugin `@sonapraneeth/gatsby-source-core`. This could potentially cause conflicts.

1. Clone the repository https://github.com/sonapraneeth-a/multiple-source-gatsby
2. cd to the repository
3. yarn install
4. yarn workspace demo-all develop

Question:

My main aim is to define interfaces and types in one package and in other source packages (like mdx based, contentful based etc.,), I want to resolve values for the types defined in the first package. I'm using schema customization.

1. What does the error in the attached image indicate?
2. Is the way implemented in the github repo, a correct implementation (or) is there any better way?