fix(pg): preserve seconds in historical Date timezone offsets

packages/pg/lib/utils.js

@@ -93,7 +93,15 @@ function prepareObject(val, seen) {
 }
 
 function dateToString(date) {
-  let offset = -date.getTimezoneOffset()
+  let offset = Math.trunc(-date.getTimezoneOffset()) * 60
+  // getTimezoneOffset() omits the seconds in historical offsets. Keep the
+  // local clock fields and recover those seconds only when they differ from UTC.
+  if (date.getSeconds() !== date.getUTCSeconds()) {
+    const localDate = new Date(date.getTime())
+    localDate.setUTCFullYear(date.getFullYear(), date.getMonth(), date.getDate())
+    localDate.setUTCHours(date.getHours(), date.getMinutes(), date.getSeconds(), date.getMilliseconds())
+    offset += ((localDate.getTime() - date.getTime()) / 1000) % 60
+  }
 
   let year = date.getFullYear()
   const isBCYear = year < 1
@@ -121,7 +129,9 @@ function dateToString(date) {
     ret += '+'
   }
 
-  ret += String(Math.floor(offset / 60)).padStart(2, '0') + ':' + String(offset % 60).padStart(2, '0')
+  ret +=
+    String(Math.floor(offset / 3600)).padStart(2, '0') + ':' + String(Math.floor(offset / 60) % 60).padStart(2, '0')
+  if (offset % 60) ret += ':' + String(offset % 60).padStart(2, '0')
   if (isBCYear) ret += ' BC'
   return ret
 }

packages/pg/test/integration/client/historical-timezone-tests.js

@@ -0,0 +1,56 @@
+'use strict'
+const helper = require('./test-helper')
+const assert = require('assert')
+const suite = new helper.Suite()
+
+const cases = [
+  ['Europe/Paris', '1890-01-01T12:00:00.123Z'],
+  ['America/New_York', '1880-01-01T12:00:00.123Z'],
+  ['Africa/Monrovia', '1970-01-01T00:00:00.000Z'],
+]
+
+for (const [zone, iso] of cases) {
+  suite.test(`historical timestamptz round trip in ${zone}`, async function () {
+    const oldTz = process.env.TZ
+    const client = new helper.pg.Client(helper.config)
+    try {
+      process.env.TZ = zone
+      await client.connect()
+      const date = new Date(iso)
+      const { rows } = await client.query(
+        'SELECT $1::timestamptz AS val, $2::timestamptz AS control, $3::timestamptz[] AS vals',
+        [date, iso, [date, date]]
+      )
+      assert.strictEqual(rows[0].control.getTime(), date.getTime())
+      assert.strictEqual(rows[0].val.getTime(), date.getTime())
+      assert.deepStrictEqual(
+        rows[0].vals.map((value) => value.getTime()),
+        [date.getTime(), date.getTime()]
+      )
+    } finally {
+      await client.end()
+      if (oldTz === undefined) delete process.env.TZ
+      else process.env.TZ = oldTz
+    }
+  })
+}
+
+suite.test('historical Date keeps local fields for timestamp and date parameters', async function () {
+  const oldTz = process.env.TZ
+  const client = new helper.pg.Client(helper.config)
+  try {
+    process.env.TZ = 'Europe/Paris'
+    await client.connect()
+    const date = new Date('1890-01-01T12:00:00.123Z')
+    const { rows } = await client.query(
+      "SELECT to_char($1::timestamp, 'YYYY-MM-DD HH24:MI:SS.MS') AS val, $2::date::text AS day",
+      [date, date]
+    )
+    assert.strictEqual(rows[0].val, '1890-01-01 12:09:21.123')
+    assert.strictEqual(rows[0].day, '1890-01-01')
+  } finally {
+    await client.end()
+    if (oldTz === undefined) delete process.env.TZ
+    else process.env.TZ = oldTz
+  }
+})

packages/pg/test/unit/historical-date-tests.js

@@ -0,0 +1,45 @@
+'use strict'
+const helper = require('./test-helper')
+const utils = require('../../lib/utils')
+const defaults = require('../../lib/defaults')
+const assert = require('assert')
+const suite = new helper.Suite()
+
+const cases = [
+  ['Europe/Paris', '1890-01-01T12:00:00.123Z', '1890-01-01T12:09:21.123+00:09:21'],
+  ['America/New_York', '1880-01-01T12:00:00.123Z', '1880-01-01T07:03:58.123-04:56:02'],
+  ['Asia/Kathmandu', '1890-01-01T12:00:00.123Z', '1890-01-01T17:41:16.123+05:41:16'],
+  ['Africa/Monrovia', '1970-01-01T00:00:00.000Z', '1969-12-31T23:15:30.000-00:44:30'],
+  ['Europe/Paris', '2014-02-01T11:11:01.007Z', '2014-02-01T12:11:01.007+01:00'],
+  ['UTC', '1890-01-01T12:00:00.123Z', '1890-01-01T12:00:00.123+00:00'],
+  ['Europe/Paris', '0000-01-01T12:00:00.123Z', '0001-01-01T12:09:21.123+00:09:21 BC'],
+]
+
+for (const [zone, iso, expected] of cases) {
+  suite.test(`Date serialization in ${zone} at ${iso}`, function () {
+    const oldTz = process.env.TZ
+    try {
+      process.env.TZ = zone
+      const date = new Date(iso)
+      assert.strictEqual(utils.prepareValue(date), expected)
+      assert.strictEqual(date.toISOString(), iso)
+    } finally {
+      if (oldTz === undefined) delete process.env.TZ
+      else process.env.TZ = oldTz
+    }
+  })
+}
+
+suite.test('UTC Date serialization does not use the historical local offset', function () {
+  const oldTz = process.env.TZ
+  const oldParseInputDatesAsUTC = defaults.parseInputDatesAsUTC
+  try {
+    process.env.TZ = 'Africa/Monrovia'
+    defaults.parseInputDatesAsUTC = true
+    assert.strictEqual(utils.prepareValue(new Date(0)), '1970-01-01T00:00:00.000+00:00')
+  } finally {
+    defaults.parseInputDatesAsUTC = oldParseInputDatesAsUTC
+    if (oldTz === undefined) delete process.env.TZ
+    else process.env.TZ = oldTz
+  }
+})