Fix missing timezone in Sqlite UTCTime string

Author: malteneuss

persistent-sqlite/ChangeLog.md

@@ -1,5 +1,11 @@
 # Changelog for persistent-sqlite
 
+## 2.13.3.1
+
+* [1585](https://github.com/yesodweb/persistent/pull/1585)
+    * Fix missing timezone "Z" in Sqlite UTCTime strings, e.g.
+      "2025-04-12T06:53:42Z"
+
 ## 2.13.3.0
 
 * [#1524](https://github.com/yesodweb/persistent/pull/1524)

persistent-sqlite/Database/Sqlite.hs

@@ -486,8 +486,13 @@ bind statement sqlData = do
        $ zip [1..] sqlData
   return ()
 
+-- | Format UTCTime value as a ISO86091 string.
+-- It contains timezone "Z" which corresponds to UTC, e.g. "2025-04-12T06:53:42Z".
+-- Note: We manually format here to support "time" package >=1.6,
+-- but consider using `Data.Time.Format.ISO8601` iso8601Show and iso8601ParseM when bumping
+-- lower "time" package bound to >=1.9.
 format8601 :: UTCTime -> String
-format8601 = formatTime defaultTimeLocale "%FT%T%Q"
+format8601 = formatTime defaultTimeLocale "%FT%T%QZ"
 
 foreign import ccall "sqlite3_column_type"
   columnTypeC :: Ptr () -> Int -> IO Int

persistent/ChangeLog.md

@@ -1,5 +1,11 @@
 # Changelog for persistent
 
+# 2.15.1.1
+
+* [#1585](https://github.com/yesodweb/persistent/pull/1585)
+    * Support parsing PersistField UTCTime from text with timezone, e.g. "2025-04-12T06:53:42Z".
+      This is needed for Sqlite, which has no native datetime support but uses e.g. TEXT.
+
 # 2.15.1.0
 
 * [#1519](https://github.com/yesodweb/persistent/pull/1519/files/9865a295f4545d30e55aacb6efc25f27f758e8ad#diff-5af2883367baae8f7f266df6a89fc2d1defb7572d94ed069e05c8135a883bc45)

persistent/Database/Persist/Class/PersistField.hs

@@ -311,7 +311,7 @@ instance PersistField UTCTime where
         in
           case NonEmpty.nonEmpty (reads s) of
             Nothing ->
-                case parse8601 s <|> parsePretty s of
+                case parse8601 s <|> parse8601NoTimezone s <|> parsePretty s <|> parsePrettyNoTimezone s of
                     Nothing -> Left $ fromPersistValueParseError "UTCTime" x
                     Just x' -> Right x'
             Just matches ->
@@ -323,12 +323,20 @@ instance PersistField UTCTime where
                 Right $ fst $ NonEmpty.last matches
       where
 #if MIN_VERSION_time(1,5,0)
+        -- Note: consider using `Data.Time.Format.ISO8601` iso8601ParseM when bumping
+        -- lower "time" package bound to >=1.9; this function require the timezone "Z",
+        -- so best suitable when e.g. dropping support non-canonial "notimezone" and "pretty" parse variants
+        -- in persistent 3.0.
         parseTime' = parseTimeM True defaultTimeLocale
 #else
         parseTime' = parseTime defaultTimeLocale
 #endif
-        parse8601 = parseTime' "%FT%T%Q"
-        parsePretty = parseTime' "%F %T%Q"
+        parse8601 = parseTime' "%FT%T%QZ"
+        parsePretty = parseTime' "%F %T%QZ"
+        -- Before 2.13.3.1 persistent-sqlite was missing the timezone "Z" for UTC,
+        -- which was only implicit, so these functions ensure backwards-compatibility.
+        parse8601NoTimezone = parseTime' "%FT%T%Q"
+        parsePrettyNoTimezone = parseTime' "%F %T%Q"
     fromPersistValue x@(PersistByteString s) =
         case reads $ unpack s of
             (d, _):_ -> Right d

persistent/test/Database/Persist/ClassSpec.hs

@@ -1,15 +1,23 @@
 module Database.Persist.ClassSpec where
 
-import Database.Persist.Class
 import Data.Time
+import Database.Persist.Class
 import Database.Persist.Types
 import Test.Hspec
 
 spec :: Spec
 spec = describe "Class" $ do
     describe "PersistField" $ do
         describe "UTCTime" $ do
-            it "fromPersistValue with format" $
+            it "fromPersistValue with ISO8601 format including UTC timezone Z (canonical)" $
+                fromPersistValue (PersistText "2018-02-27T10:49:42.123Z")
+                    `shouldBe` Right
+                        (UTCTime (fromGregorian 2018 02 27) (timeOfDayToTime (TimeOfDay 10 49 42.123)))
+            it "fromPersistValue with ISO8601 format no timezone (backwards-compatibility)" $
+                fromPersistValue (PersistText "2018-02-27T10:49:42.123")
+                    `shouldBe` Right
+                        (UTCTime (fromGregorian 2018 02 27) (timeOfDayToTime (TimeOfDay 10 49 42.123)))
+            it "fromPersistValue with pretty format (backwards-compatibility)" $
                 fromPersistValue (PersistText "2018-02-27 10:49:42.123")
-                    `shouldBe`
-                        Right (UTCTime (fromGregorian 2018 02 27) (timeOfDayToTime (TimeOfDay 10 49 42.123)))
+                    `shouldBe` Right
+                        (UTCTime (fromGregorian 2018 02 27) (timeOfDayToTime (TimeOfDay 10 49 42.123)))