drivers/nodejs/src/index.ts

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import { Client } from 'pg'
import pgTypes from 'pg-types'
import { CharStreams, CommonTokenStream } from 'antlr4ts'
import { AgtypeLexer } from './antlr4/AgtypeLexer'
import { AgtypeParser } from './antlr4/AgtypeParser'
import CustomAgTypeListener from './antlr4/CustomAgTypeListener'
import { ParseTreeWalker } from 'antlr4ts/tree'

function AGTypeParse (input: string) {
  const chars = CharStreams.fromString(input)
  const lexer = new AgtypeLexer(chars)
  const tokens = new CommonTokenStream(lexer)
  const parser = new AgtypeParser(tokens)
  const tree = parser.agType()
  const printer = new CustomAgTypeListener()
  ParseTreeWalker.DEFAULT.walk(printer, tree)
  return printer.getResult()
}

async function setAGETypes (client: Client, types: typeof pgTypes) {
  await client.query(`
        CREATE EXTENSION IF NOT EXISTS age;
        LOAD 'age';
        SET search_path = ag_catalog, "$user", public;
    `)

  const oidResults = await client.query(`
        select typelem
        from pg_type
        where typname = '_agtype';`)

  if (oidResults.rows.length < 1) { throw new Error() }

  types.setTypeParser(oidResults.rows[0].typelem, AGTypeParse)
}

export { setAGETypes, AGTypeParse }