Testing https://github.com/octokit/graphql.js/issues/61#issuecomment-1221923173 in Deno

readme.md

• See octokit/graphql.js#61 (comment) for the context
• Implementation code is copied from davelosert/graphql-pagination#1

To test it locally:

1. Set GITHUB_TOKEN env var to your GitHub personall access token
2. Run with

deno run https://gist.githubusercontent.com/laughedelic/55a288f3780b11d4da3526c23cc5142e/raw/74f03b7e8c56f93b2d6e31895967a7c3a18124f8/paginate-graphql-test.ts

You can get the latest link by clicking Raw button on the paginate-graphql-test.ts file.

paginate-graphql-test.ts

import { Octokit } from "https://cdn.skypack.dev/@octokit/core?dts";
import { Kind, parse, visit } from "https://cdn.skypack.dev/graphql?dts";

interface PaginationItem {
  location: string;
  cursorVariableName: string;
}

const extractPaginatedItems = (query: string): PaginationItem[] => {
  const ast = parse(query, { noLocation: true });

  const currentPath: string[] = [];
  const paginationInfos: PaginationItem[] = [];

  visit(ast, {
    enter(node, key, parent, path, ancestors) {
      if (node.kind === Kind.FIELD) {
        currentPath.push(node.name.value);
      }

      if (
        node.kind === Kind.ARGUMENT &&
        node.name.value === "after" &&
        node.value.kind === Kind.VARIABLE
      ) {
        paginationInfos.push({
          location: currentPath.join("."),
          cursorVariableName: node.value.name.value,
        });
      }
    },
    leave(node) {
      if (node.kind === Kind.FIELD) {
        currentPath.pop();
      }
    },
  });

  return paginationInfos;
};

const getObjectByPosition = (obj: any, positionStr: string) => {
  const position = positionStr.split(".");
  return position.reduce((current, nextProperty) => current[nextProperty], obj);
};

const paginateComplex = (octokit: Octokit) => {
  return async (query: string) => {
    // Find Argument with name 'after' and get
    // 1. the value.name.value of a type 'Variable'
    // 2. the path to the paginated entity (which is either nodes or edges)
    const paginationItems = extractPaginatedItems(query);
    const { cursorVariableName, location } = paginationItems[0];

    let hasNextPage = true;
    let nextCursor = undefined;
    let allNodes = [];

    while (hasNextPage) {
      const result = await octokit.graphql(query, {
        [cursorVariableName]: nextCursor,
      }) as any;
      const paginatedEntity = getObjectByPosition(result, location);
      const { nodes, pageInfo } = paginatedEntity;
      allNodes.push(...nodes);
      hasNextPage = pageInfo.hasNextPage;
      nextCursor = pageInfo.endCursor;
    }

    return {
      repository: {
        issues: allNodes,
      },
    };
  };
};

//////////////////////////////////////////////////////////////////////////////////////////////

const octokit = new Octokit({
  auth: Deno.env.get("GITHUB_TOKEN"),
});

const paginate = paginateComplex(octokit);

const result = await paginate(`#graphql
  query paginate($cursor1: String) {
    repository(owner: "octokit", name: "rest.js") {
      issues(first: 10, after: $cursor1) {
        pageInfo {
          endCursor
          hasNextPage
        }
        nodes { 
          title
        }
      }
    }
  }
`);

console.log(JSON.stringify(result, null, 2));