Assert exact serialized value and match warning by code

Co-authored-by: charmander <1889843+charmander@users.noreply.github.com>

Author: Copilot

packages/pg/lib/utils.js

@@ -1,13 +1,14 @@
 'use strict'
 
 const defaults = require('./defaults')
-const nodeUtils = require('util')
+const { deprecate, types } = require('util')
 
-const { isDate } = require('util/types')
+const { isDate } = types
 
-const invalidDateDeprecationNotice = nodeUtils.deprecate(
+const invalidDateDeprecationNotice = deprecate(
   () => {},
-  'Sending an invalid date to Postgres is deprecated and will throw an error in the next major version of pg. Ensure any Date object passed as a query parameter is valid.'
+  'Sending an invalid date to Postgres is deprecated and will throw an error in the next major version of pg. Ensure any Date object passed as a query parameter is valid.',
+  'PG_INVALID_DATE'
 )
 
 function escapeElement(elementRepresentation) {

packages/pg/test/unit/utils-tests.js

@@ -92,30 +92,20 @@ test('prepareValues: 1 BC date prepared properly', function () {
 test('prepareValues: invalid date emits deprecation warning', function () {
   const date = new Date(undefined)
 
-  // util.deprecate (used internally) only ever emits its warning once per process,
-  // so build a promise that resolves as soon as we observe it, and race it against
-  // a short timeout so the test fails fast instead of hanging if it's not emitted.
-  const warningPromise = new Promise((resolve, reject) => {
+  const warningPromise = new Promise((resolve) => {
     const onWarning = (warning) => {
-      if (warning.name === 'DeprecationWarning' && /invalid date/i.test(warning.message)) {
-        clearTimeout(timer)
+      if (warning.code === 'PG_INVALID_DATE') {
         process.removeListener('warning', onWarning)
         resolve(warning)
       }
     }
     process.on('warning', onWarning)
-
-    const timer = setTimeout(() => {
-      process.removeListener('warning', onWarning)
-      reject(new Error('Expected a DeprecationWarning about invalid dates but none was emitted'))
-    }, 500)
   })
 
   const out = utils.prepareValue(date)
 
   // still serializes (for backwards compatibility) but warns that this is deprecated
-  assert.strictEqual(typeof out, 'string')
-  assert.ok(out.includes('NaN'))
+  assert.strictEqual(out, '0NaN-NaN-NaNTNaN:NaN:NaN.NaN+NaN:NaN')
 
   return warningPromise
 })