TodoPlugin.ts

import { withPgClient, withPgClientTransaction } from "@dataplan/pg";
import { context, each, lambda, object } from "grafast";
import { gql, makeExtendSchemaPlugin } from "graphile-utils";

/**
 * TodoPlugin
 */
export const TodoPlugin = makeExtendSchemaPlugin((build) => {
  const { sql, input } = build;
  const executor = input.pgSources[0].executor;
  const todos = build.input.pgSources.find(
    (s) => s.extensions?.pg && s.extensions.pg.name === "todos"
  );
  if (!todos) {
    throw new Error("Couldn't find todos source");
  }
  if (!sql) {
    throw new Error("SQL is not available");
  }
  return {
    typeDefs: gql`
      input TodosInput {
        userId: String!
      }
      type TodosPayload {
        todos: [Todo!]!
      }
      extend type Mutation {
        fetchTodos(input: TodosInput!): TodosPayload
      }
    `,
    plans: {
      Mutation: {
        fetchTodos(_$root, fieldArgs) {
          const $rootPgPool = context().get("rootPgPool");
          const $input = object({
            userId: fieldArgs.get(["input", "userId"]),
          });
          /**
           * Fetch and insert data
           */
          withPgClient(
            executor,
            object({
              input: $input,
              rootPgPool: $rootPgPool,
            }),
            async (_client, data) => {
              const { userId } = data?.input;
              const todos = await getTodosAPI({
                input: { userId: userId },
              });

              if (!todos) throw new Error("Couldn't find Todos");

              //Insert todos into postgres
            }
          );
          /**
           * Handle transactions
           */
          const $transactionResult = withPgClientTransaction(
            executor,
            object({
              input: $input,
              rootPgPool: $rootPgPool,
            }),
            async (client, data) => {
              const { userId } = data?.input;
              const { rows } = await client.query(
                sql.compile(
                  sql`SELECT *
                      FROM app_public.todos
                      WHERE user_id=${sql.value(userId)}`
                )
              );
              return rows;
            }
          );
          return $transactionResult;
        },
      },
      TodosPayload: {
        todos($transactionResult) {
          const $ids = lambda($transactionResult, (records) =>
            records.map((record) => record.id)
          );
          return each($ids, ($id) => todos.get({ id: $id }));
        },
      },
    },
  };
});

export default TodoPlugin;