pg: Re-export DatabaseError from 'pg-protocol'

Before, users would have to import DatabaseError from 'pg-protocol'.  If
there are multiple versions of 'pg-protocol', you might end up using the
wrong one.

Closes brianc#2378

Author: cakoose

Diff for: packages/pg/lib/index.js

@@ -4,6 +4,7 @@ var Client = require('./client')
 var defaults = require('./defaults')
 var Connection = require('./connection')
 var Pool = require('pg-pool')
+const { DatabaseError } = require('pg-protocol')
 
 const poolFactory = (Client) => {
   return class BoundPool extends Pool {
@@ -21,6 +22,7 @@ var PG = function (clientConstructor) {
   this._pools = []
   this.Connection = Connection
   this.types = require('pg-types')
+  this.DatabaseError = DatabaseError
 }
 
 if (typeof process.env.NODE_PG_FORCE_NATIVE !== 'undefined') {

Diff for: packages/pg/test/integration/client/error-handling-tests.js

@@ -151,7 +151,7 @@ suite.test('non-query error with callback', function (done) {
   })
   client.connect(
     assert.calls(function (error, client) {
-      assert(error instanceof Error)
+      assert(error instanceof pg.DatabaseError)
       done()
     })
   )
@@ -182,7 +182,7 @@ suite.test('when connecting to an invalid host with callback', function (done) {
     assert.fail('unexpected error event when connecting')
   })
   client.connect(function (error, client) {
-    assert(error instanceof Error)
+    assert(error instanceof pg.DatabaseError)
     done()
   })
 })
@@ -202,7 +202,7 @@ suite.test('non-query error', function (done) {
     user: 'asldkfjsadlfkj',
   })
   client.connect().catch((e) => {
-    assert(e instanceof Error)
+    assert(e instanceof pg.DatabaseError)
     done()
   })
 })