Treat postgres bigint as string by default

Author: porsager

README.md

@@ -493,11 +493,19 @@ prexit(async () => {
 
 `Number` in javascript is only able to represent 2<sup>53</sup>-1 safely which means that types in PostgreSQLs like `bigint` and `numeric` won't fit into `Number`.
 
-Since Node.js v10.4 we can use [`BigInt`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt) to match the PostgreSQL type `bigint`, so Postgres.js will use BigInt if running on v10.4 or later. For older versions `bigint` will be returned as a string.
+Since Node.js v10.4 we can use [`BigInt`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt) to match the PostgreSQL type `bigint` which is returned for eg. `count(*)`. Unfortunately it doesn't work with `JSON.stringify` out of the box, so Postgres.js will return it as a string. 
 
-There is currently no way to handle `numeric / decimal` in a native way in Javascript, so these and similar will be returned as `string`.
+If you want to use `BigInt` you can add this custom type:
 
-You can of course handle types like these using [custom types](#types) if you want to.
+```js
+const sql = postgres({
+  types: {
+    bigint: postgres.BigInt
+  }
+})
+```
+
+There is currently no way to handle `numeric / decimal` in a native way in Javascript, so these and similar will be returned as `string`. You can also handle types like these using [custom types](#types) if you want to.
 
 ## The Connection Pool
 

lib/index.js

@@ -31,7 +31,13 @@ function notTagged() {
 Object.assign(Postgres, {
   toPascal,
   toCamel,
-  toKebab
+  toKebab,
+  BigInt: {
+    to: 20,
+    from: [20],
+    parse: x => BigInt(x), // eslint-disable-line
+    serialize: x => x.toString()
+  }
 })
 
 const originCache = new Map()

lib/types.js

@@ -2,7 +2,7 @@ const char = (acc, [k, v]) => (acc[k.charCodeAt(0)] = v, acc)
 const entries = o => Object.keys(o).map(x => [x, o[x]])
 
 // These were the fastest ways to do it in Node.js v12.11.1 (add tests to revise if this changes)
-const types = module.exports.types = Object.assign({
+const types = module.exports.types = {
   string: {
     to: 25,
     from: null,             // defaults to string
@@ -38,16 +38,7 @@ const types = module.exports.types = Object.assign({
     serialize: x => '\\x' + x.toString('hex'),
     parse: x => Buffer.from(x.slice(2), 'hex')
   }
-},
-  typeof BigInt === 'undefined' ? {} : {
-    bigint: {
-      to: 20,
-      from: [20],
-      parse: data => BigInt(data), // eslint-disable-line
-      serialize: bigint => bigint.toString()
-    }
-  }
-)
+}
 
 const defaultHandlers = typeHandlers(types)
 

tests/index.js

@@ -198,7 +198,7 @@ t('Transaction succeeds on caught savepoint', async() => {
     await sql`insert into test values(3)`
   })
 
-  return [typeof BigInt === 'undefined' ? '2' : 2n, (await sql`select count(1) from test`)[0].count, await sql`drop table test`]
+  return ['2', (await sql`select count(1) from test`)[0].count, await sql`drop table test`]
 })
 
 t('Savepoint returns Result', async() => {
@@ -875,8 +875,8 @@ t('Debug works', async() => {
   return ['select 1', result]
 })
 
-t('bigint is returned as BigInt', async() => [
-  'bigint',
+t('bigint is returned as String', async() => [
+  'string',
   typeof (await sql`select 9223372036854777 as x`)[0].x
 ])
 
@@ -890,10 +890,6 @@ t('numeric is returned as string', async() => [
   typeof (await sql`select 1.2 as x`)[0].x
 ])
 
-function get() {
-  return sql`selec 1`
-}
-
 t('Async stack trace', async() => {
   return [
     parseInt(new Error().stack.split('\n')[1].split(':')[1]) + 1,