Merge pull request #741 from yesodweb/persistentErrorMessages

More verbose error messages when failing to parse database results in…
yesodweb · Jan 17, 2018 · 453ef08 · 453ef08
2 parents 57f2b96 + 36dffb5
commit 453ef08
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diff --git a/persistent-template/ChangeLog.md b/persistent-template/ChangeLog.md
@@ -1,3 +1,7 @@
+## 2.5.3.1
+
+* Slight improvement to the error message when a Persistent field can't be parsed from database results
+
 ## 2.5.3
 
 * Exposed `parseReferences` to allow custom QuasiQuoters

diff --git a/persistent-template/Database/Persist/TH.hs b/persistent-template/Database/Persist/TH.hs
@@ -615,7 +615,7 @@ mapLeft _ (Right r) = Right r
 mapLeft f (Left l)  = Left (f l)
 
 fieldError :: Text -> Text -> Text
-fieldError fieldName err = "field " `mappend` fieldName `mappend` ": " `mappend` err
+fieldError fieldName err = "Couldn't parse field `" `mappend` fieldName `mappend` "` from database results: " `mappend` err
 
 mkFromPersistValues :: MkPersistSettings -> EntityDef -> Q [Clause]
 mkFromPersistValues _ t@(EntityDef { entitySum = False }) =

diff --git a/persistent-template/persistent-template.cabal b/persistent-template/persistent-template.cabal
@@ -1,5 +1,5 @@
 name:            persistent-template
-version:         2.5.3
+version:         2.5.3.1
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>

diff --git a/persistent/ChangeLog.md b/persistent/ChangeLog.md
@@ -1,3 +1,8 @@
+## 2.7.3.1
+
+ * Improve error messages when failing to parse database results into Persistent records.
+ * A handful of `fromPersistField` implementations called `error` instead of returning a `Left Text`. All of the implementations were changed to return `Left`.
+
 ## 2.7.3 
 
 * Reverts [#723](https://github.com/yesodweb/persistent/pull/723), which generalized functions using the `BackendCompatible` class. These changes were an accidental breaking change.

diff --git a/persistent/Database/Persist/Class/PersistField.hs b/persistent/Database/Persist/Class/PersistField.hs
diff --git a/persistent/Database/Persist/Sql/Orphan/PersistStore.hs b/persistent/Database/Persist/Sql/Orphan/PersistStore.hs
@@ -320,7 +320,7 @@ instance PersistStoreRead SqlBackend where
                 Nothing -> return Nothing
                 Just vals ->
                     case fromPersistValues $ if noColumns then [] else vals of
-                        Left e -> error $ "get " ++ show k ++ ": " ++ unpack e
+                        Left e -> error $ "Error when calling `get` with key: " ++ show k ++ ". Failed to create `" ++ (unpack (unHaskellName $ entityHaskell t)) ++  "` because of error: " ++ unpack e ++ " Potential solution: If your field is using a custom PersistField instance, check that it's correct."
                         Right v -> return $ Just v
 instance PersistStoreRead SqlReadBackend where
     get k = withReaderT persistBackend $ get k

diff --git a/persistent/persistent.cabal b/persistent/persistent.cabal
@@ -1,5 +1,5 @@
 name:            persistent
-version:         2.7.3
+version:         2.7.3.1
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>