Fix format handling of quoted text next to a time zone token, closed #…

…136

src/format/index.js

@@ -321,10 +321,23 @@ export default function format(dirtyDate, dirtyFormatStr, dirtyOptions) {
   var matches = formatStr.match(tzFormattingTokensRegExp)
   if (matches) {
     var date = toDate(dirtyDate, options)
+    // Work through each match and replace the tz token in the format string with the quoted
+    // formatted time zone so the remaining tokens can be filled in by date-fns#format.
     formatStr = matches.reduce(function (result, token) {
-      return token[0] === "'"
-        ? result
-        : result.replace(token, "'" + formatters[token[0]](date, token, null, options) + "'")
+      if (token[0] === "'") {
+        return result // This is a quoted portion, matched only to ensure we don't match inside it
+      }
+      var pos = result.indexOf(token)
+      var precededByQuotedSection = result[pos - 1] === "'"
+      var replaced = result.replace(
+        token,
+        "'" + formatters[token[0]](date, token, null, options) + "'"
+      )
+      // If the replacement results in two adjoining quoted strings, the back to back quotes
+      // are removed so it doesn't look like an escaped quote.
+      return precededByQuotedSection
+        ? replaced.substring(0, pos - 1) + replaced.substring(pos + 1)
+        : replaced
     }, formatStr)
   }
 

src/format/test.js

@@ -4,6 +4,7 @@
 import assert from 'power-assert'
 import format from '.'
 import enGB from 'date-fns/locale/en-GB'
+import utcToZonedTime from '../utcToZonedTime'
 
 describe('format', function () {
   var date = new Date(1986, 3 /* Apr */, 4, 10, 32, 55, 123)
@@ -667,6 +668,13 @@ describe('format', function () {
       })
       assert(result === dateAndTimeZoneAmericaNY)
     })
+
+    it('handles quoted text next to a time zone token', function () {
+      var timeZone = 'Europe/Paris'
+      var result = format(utcToZonedTime(date, timeZone), "dd.MM.yyyy HH:mm 'UTC'xxx", { timeZone })
+
+      assert(result === '04.04.1986 11:32 UTC+02:00')
+    })
   })
 
   describe('timestamp', function () {