Hooks up event trigger codecs from #7237. This required fixing a problem where some backend types implemented `defaultTriggerOnReplication` with `error` which caused the server to crash when evaluating those for default values in codecs. The changes here add a type family to `Backend` called `XEventTriggers` that signals backend support for event triggers, and changes the type of `defaultTriggerOnReplication` to from `TriggerOnReplication` to `Maybe (XEventTriggers b, TriggerOnReplication)` so that it can only be implemented with a `Just` value if `XEventTriggers b` is inhabited. This emulates some existing type families in `Backend`. (Thanks to @daniel-chambers for this suggestion!)
I used the implementation of `defaultTriggerOnReplication` as a signal for event triggers support to prune the Metadata API so that event trigger fields will not appear in the OpenAPI spec for backend types that do not support event triggers. The codec version of the API will also not emit or accept those fields for those backend types. I think I could use `Typeable` to test whether `XEventTriggers` is `Void` instead of testing whether `defaultTriggerOnReplication` is `Nothing`. But the codec implementation will crash anyway if `defaultTriggerOnReplication` is `Nothing`.
I checked to make sure that graphql-engine-pro still compiles.
Ticket: https://hasurahq.atlassian.net/browse/GDC-521
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7295
GitOrigin-RevId: 2b2dd44291513266107ca25cf330319bf53a8b66
## Description ✍️
This PR introduces a new feature to enable/disable event triggers during logical replication of table data for PostgreSQL and MS-SQL data sources. We introduce a new field `trigger_on_replication` in the `*_create_event_trigger` metadata API. By default the event triggers will not fire for logical data replication.
## Changelog ✍️
__Component__ : server
__Type__: feature
__Product__: community-edition
### Short Changelog
Add option to enable/disable event triggers on logically replicated tables
### Related Issues ✍
https://github.com/hasura/graphql-engine/issues/8814https://hasurahq.atlassian.net/browse/GS-252
### Solution and Design
- By default, triggers do **not** fire when the session mode is `replica` in Postgres, so if the `triggerOnReplication` is set to `true` for an event trigger we run the query `ALTER TABLE #{tableTxt} ENABLE ALWAYS TRIGGER #{triggerNameTxt};` so that the trigger fires always irrespective of the `session_replication_role`
- By default, triggers do fire in case of replication in MS-SQL, so if the `triggerOnReplication` is set to `false` for an event trigger we add a clause `NOT FOR REPLICATION` to the the SQL when the trigger is created/altered, which sets the `is_not_for_replication` for the trigger as `true` and it does not fire during logical replication.
### Steps to test and verify ✍
- Run hspec integration tests for HGE
## Server checklist ✍
### Metadata ✍
Does this PR add a new Metadata feature?
- ✅ Yes
- Does `export_metadata`/`replace_metadata` supports the new metadata added?
- ✅
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6953
Co-authored-by: Puru Gupta <32328846+purugupta99@users.noreply.github.com>
Co-authored-by: Sean Park-Ross <94021366+seanparkross@users.noreply.github.com>
GitOrigin-RevId: 92731328a2bbdcad2302c829f26f9acb33c36135
### Description
This monster of a PR took way too long. As the title suggests, it reduces the schema context carried in the readers to the very strict minimum. In practice, that means that to build a source, we only require:
- the global `SchemaContext`
- the global `SchemaOptions` (soon to be renamed `SchemaSourceOptions`)
- that source's `SourceInfo`
Furthermore, _we no longer carry "default" customization options throughout the schema_. All customization information is extracted from the `SourceInfo`, when required. This prevents an entire category of bugs we had previously encountered, such as parts of the code using uninitialized / unupdated customization info.
In turn, this meant that we could remove the explicit threading of the `SourceInfo` throughout the schema, since it is now always available through the reader context.
Finally, this meant making a few adjustments to relay and actions as well, such as the introduction of a new separate "context" for actions, and a change to how we create some of the action-specific postgres scalar parsers.
I'll highlight with review comments the areas of interest.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6709
GitOrigin-RevId: ea80fddcb24e2513779dd04b0b700a55f0028dd1
This upgrades the version of Ormolu required by the HGE repository to v0.5.0.1, and reformats all code accordingly.
Ormolu v0.5 reformats code that uses infix operators. This is mostly useful, adding newlines and indentation to make it clear which operators are applied first, but in some cases, it's unpleasant. To make this easier on the eyes, I had to do the following:
* Add a few fixity declarations (search for `infix`)
* Add parentheses to make precedence clear, allowing Ormolu to keep everything on one line
* Rename `relevantEq` to `(==~)` in #6651 and set it to `infix 4`
* Add a few _.ormolu_ files (thanks to @hallettj for helping me get started), mostly for Autodocodec operators that don't have explicit fixity declarations
In general, I think these changes are quite reasonable. They mostly affect indentation.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6675
GitOrigin-RevId: cd47d87f1d089fb0bc9dcbbe7798dbceedcd7d83
The intent is to generalize `columnParser` to the point where it is the same across all backends, and then remove the interface in favor of a single implementation.
This extracts out `enumParser` and `possiblyNullable` as the two main areas that differ across backends. We may split `possiblyNullable` further so that we can extract some of that logic out into a common function too.
With these changes, the various `columnParser` implementations become semantically equivalent. They still do different things, and so reconciling them will require further changes.
Co-Authored-By: Antoine Leblanc <antoine@hasura.io>
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5841
GitOrigin-RevId: eec1770931eed5d72da70c97d7d0f00e33fa15d2
### Description
This PR changes all the schema code to operate in a specific `SchemaT` monad, rather than in an arbitrary `m` monad. `SchemaT` is intended to be used opaquely with `runSourceSchema` and `runRemoteSchema`. The main goal of this is to allow a different reader context per part of the schema: this PR also minimizes the contexts. This means that we no longer require `SchemaOptions` when building remote schemas' schema, and this PR therefore removes a lot of dummy / placeholder values accordingly.
### Performance and stacking
This PR has been through several iterations. #5339 was the original version, that accomplished the same thing by stacking readers on top of the stack at every remote relationship boundary. This raised performance concerns, and @0x777 confirmed with an ad-hoc test that in some extreme cases we could see up to a 10% performance impact. This version, while more verbose, allows us to unstack / re-stack the readers, and avoid that problem. #5517 adds a new benchmark set to be able to automatically measure this on every PR.
### Remaining work
- [x] a comment (or perhaps even a Note?) should be added to `SchemaT`
- [x] we probably want for #5517 to be merged first so that we can confirm the lack of performance penalty
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5458
GitOrigin-RevId: e06b83d90da475f745b838f1fd8f8b4d9d3f4b10
This makes it easier to refactor `BackendSchema`, because if the type of a type class method is changed, it's easier to update the corresponding dummy implementations.
Partially addresses hasura/graphql-engine-mono#2971, in the sense that this aids refactors.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5443
GitOrigin-RevId: 65e169d01415a04e7c419a628cf32e743448543d
Followup to hasura/graphql-engine-mono#4713.
The `memoizeOn` method, part of `MonadSchema`, originally had the following type:
```haskell
memoizeOn
:: (HasCallStack, Ord a, Typeable a, Typeable b, Typeable k)
=> TH.Name
-> a
-> m (Parser k n b)
-> m (Parser k n b)
```
The reason for operating on `Parser`s specifically was that the `MonadSchema` effect would additionally initialize certain `Unique` values, which appear (nested in) the type of `Parser`.
hasura/graphql-engine-mono#518 changed the type of `memoizeOn`, to additionally allow memoizing `FieldParser`s. These also contained a `Unique` value, which was similarly initialized by the `MonadSchema` effect. The new type of `memoizeOn` was as follows:
```haskell
memoizeOn
:: forall p d a b
. (HasCallStack, HasDefinition (p n b) d, Ord a, Typeable p, Typeable a, Typeable b)
=> TH.Name
-> a
-> m (p n b)
-> m (p n b)
```
Note the type `p n b` of the value being memoized: by choosing `p` to be either `Parser k` or `FieldParser`, both can be memoized. Also note the new `HasDefinition (p n b) d` constraint, which provided a `Lens` for accessing the `Unique` value to be initialized.
A quick simplification is that the `HasCallStack` constraint has never been used by any code. This was realized in hasura/graphql-engine-mono#4713, by removing that constraint.
hasura/graphql-engine-mono#2980 removed the `Unique` value from our GraphQL-related types entirely, as their original purpose was never truly realized. One part of removing `Unique` consisted of dropping the `HasDefinition (p n b) d` constraint from `memoizeOn`.
What I didn't realize at the time was that this meant that the type of `memoizeOn` could be generalized and simplified much further. This PR finally implements that generalization. The new type is as follows:
```haskell
memoizeOn ::
forall a p.
(Ord a, Typeable a, Typeable p) =>
TH.Name ->
a ->
m p ->
m p
```
This change has a couple of consequences.
1. While constructing the schema, we often output `Maybe (Parser ...)`, to model that the existence of certain pieces of GraphQL schema sometimes depends on the permissions that a certain role has. The previous versions of `memoizeOn` were not able to handle this, as the only thing they could memoize was fully-defined (if not yet fully-evaluated) `(Field)Parser`s. This much more general API _would_ allow memoizing `Maybe (Parser ...)`s. However, we probably have to be continue being cautious with this: if we blindly memoize all `Maybe (Parser ...)`s, the resulting code may never be able to decide whether the value is `Just` or `Nothing` - i.e. it never commits to the existence-or-not of a GraphQL schema fragment. This would manifest as a non-well-founded knot tying, and this would get reported as an error by the implementation of `memoizeOn`.
tl;dr: This generalization _technically_ allows for memoizing `Maybe` values, but we probably still want to avoid doing so.
For this reason, the PR adds a specialized version of `memoizeOn` to `Hasura.GraphQL.Schema.Parser`.
2. There is no longer any need to connect the `MonadSchema` knot-tying effect with the `MonadParse` effect. In fact, after this PR, the `memoizeOn` method is completely GraphQL-agnostic, and so we implement hasura/graphql-engine-mono#4726, separating `memoizeOn` from `MonadParse` entirely - `memoizeOn` can be defined and implemented as a general Haskell typeclass method.
Since `MonadSchema` has been made into a single-type-parameter type class, it has been renamed to something more general, namely `MonadMemoize`. Its only task is to memoize arbitrary `Typeable p` objects under a combined key consisting of a `TH.Name` and a `Typeable a`.
Also for this reason, the new `MonadMemoize` has been moved to the more general `Control.Monad.Memoize`.
3. After this change, it's somewhat clearer what `memoizeOn` does: it memoizes an arbitrary value of a `Typeable` type. The only thing that needs to be understood in its implementation is how the manual blackholing works. There is no more semantic interaction with _any_ GraphQL code.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4725
Co-authored-by: Daniel Harvey <4729125+danieljharvey@users.noreply.github.com>
GitOrigin-RevId: 089fa2e82c2ce29da76850e994eabb1e261f9c92
### Description
By definition, root fields are at the root of the schema: only functions that craft root fields need to know about how to customize the name of root fields. However, the presence of `Has MkRootFieldName` in `MonadBuildSchemaBase` meant that the entirety of the schema building code was implicitly aware of / capable of altering root field names.
This PR removes this constraint, and moves it to the functions that do craft root fields. This has several upsides:
- it makes it more explicit where root fields are being crafted
- it prevents functions that should not use this from mistakenly applying it to non-root fields
- it simplifies the shared schema context
### Future work
- can we maybe pass this as an argument, instead of making it a required part of the context?
- ~~AFAICT, we only ever use `mempty` for it: is this actually dead code that we should actually just remove altogether?~~
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5235
GitOrigin-RevId: 4268751f3ab87ae8e03b6fe9e1efa1b096200027
### Description
I am not 100% sure about this PR; while I think the code is better this way, I'm willing to be convinced otherwise.
In short, this PR moves the `RoleName` field into the `SchemaContext`, instead of being a nebulous `Has RoleName` constraint on the reader monad. The major upside of this is that it makes it an explicit named field, rather than something that must be given as part of a tuple of arguments when calling `runReader`.
However, the downside is that it breaks the helper permissions functions of `Schema.Table`, which relied on `Has RoleName r`. This PR makes the choice of passing the role name explicitly to all of those functions, which in turn means first explicitly fetching the role name in a lot of places. It makes it more explicit when a schema building block relies on the role name, but is a bit verbose...
### Alternatives
Some alternatives worth considering:
- attempting something like `Has context r, Has RoleName context`, which would allow them to be independent from the context but still fetch the role name from the reader, but might require type annotations to not be ambiguous
- keeping the permission functions the same, with `Has RoleName r`, and introducing a bunch of newtypes instead of using tuples to explicitly implement all the required `Has` instances
- changing the permission functions to `Has SchemaContext r`, since they are functions used only to build the schema, and therefore may be allowed to be tied to the context.
What do y'all think?
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5073
GitOrigin-RevId: 8fd09fafb54905a4d115ef30842d35da0c3db5d2
In the process of decoupling the schema parsers from the GraphQL Engine, we need to remove dependencies on `Hasura.Base.Error`.
First of all, we have avoided using `QErr` in schema parsers code, instead returning a more appropriate data type which can be converted to a `Hasura.Base.Error.QErr` later.
Secondly, we create a new `ParseErrorCode` type to represent parse failure types, which are then converted to a `Hasura.Base.Error.Code` later.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5181
GitOrigin-RevId: 8655e26adb1e7d5e3d552c77a8a403f987b53467
This introduces an `ErrorMessage` newtype which wraps `Text` in a manner which is designed to be easy to construct, and difficult to deconstruct.
It provides functionality similar to `Data.Text.Extended`, but designed _only_ for error messages. Error messages are constructed through `fromString`, concatenation, or the `toErrorValue` function, which is designed to be overridden for all meaningful domain types that might show up in an error message. Notably, there are not and should never be instances of `ToErrorValue` for `String`, `Text`, `Int`, etc. This is so that we correctly represent the value in a way that is specific to its type. For example, all `Name` values (from the _graphql-parser-hs_ library) are single-quoted now; no exceptions.
I have mostly had to add `instance ToErrorValue` for various backend types (and also add newtypes where necessary). Some of these are not strictly necessary for this changeset, as I had bigger aspirations when I started. These aspirations have been tempered by trying and failing twice.
As such, in this changeset, I have started by introducing this type to the `parseError` and `parseErrorWith` functions. In the future, I would like to extend this to the `QErr` record and the various `throwError` functions, but this is a much larger task and should probably be done in stages.
For now, `toErrorMessage` and `fromErrorMessage` are provided for conversion to and from `Text`, but the intent is to stop exporting these once all error messages are converted to the new type.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/5018
GitOrigin-RevId: 84b37e238992e4312255a87ca44f41af65e2d89a
This moves `MkTypename` and `NamingCase` into their own modules, with the intent of reducing the scope of the schema parsers code, and trying to reduce imports of large modules when small ones will do.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4978
GitOrigin-RevId: 19541257fe010035390f6183a4eaa37bae0d3ca1
The code that builds the GraphQL schema, and `buildGQLContext` in particular, is partial: not every value of `(ServerConfigCtx, GraphQLQueryType, SourceCache, HashMap RemoteSchemaName (RemoteSchemaCtx, MetadataObject), ActionCache, AnnotatedCustomTypes)` results in a valid GraphQL schema. When it fails, we want to be able to return better error messages than we currently do.
The key thing that is missing is a way to trace back GraphQL type information to their origin from the Hasura metadata. Currently, we have a number of correctness checks of our GraphQL schema. But these correctness checks only have access to pure GraphQL type information, and hence can only report errors in terms of that. Possibly the worst is the "conflicting definitions" error, which, in practice, can only be debugged by Hasura engineers. This is terrible DX for customers.
This PR allows us to print better error messages, by adding a field to the `Definition` type that traces the GraphQL type to its origin in the metadata. So the idea is simple: just add `MetadataObjId`, or `Maybe` that, or some other sum type of that, to `Definition`.
However, we want to avoid having to import a `Hasura.RQL` module from `Hasura.GraphQL.Parser`. So we instead define this additional field of `Definition` through a new type parameter, which is threaded through in `Hasura.GraphQL.Parser`. We then define type synonyms in `Hasura.GraphQL.Schema.Parser` that fill in this type parameter, so that it is not visible for the majority of the codebase.
The idea of associating metadata information to `Definition`s really comes to fruition when combined with hasura/graphql-engine-mono#4517. Their combination would allow us to use the API of fatal errors (just like the current `MonadError QErr`) to report _inconsistencies_ in the metadata. Such inconsistencies are then _automatically_ ignored. So no ad-hoc decisions need to be made on how to cut out inconsistent metadata from the GraphQL schema. This will allow us to report much better errors, as well as improve the likelihood of a successful HGE startup.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4770
Co-authored-by: Samir Talwar <47582+SamirTalwar@users.noreply.github.com>
GitOrigin-RevId: 728402b0cae83ae8e83463a826ceeb609001acae
Pretty much all quasi-quoted names in the server code base have ended up in `Hasura.GraphQL.Parser.Constants`. I'm now finding this unpleasant for two reasons:
1. I would like to factor out the parser code into its own Cabal package, and I don't want to have to expose all these names.
2. Most of them really have nothing to do with the parsers.
In order to remedy this, I have:
1. moved the names used by parser code to `Hasura.GraphQL.Parser.DirectiveName`, as they're all related to directives;
2. moved `Hasura.GraphQL.Parser.Constants` to `Hasura.Name`, changing the qualified import name from `G` to `Name`;
3. moved names only used in tests to the appropriate test case;
4. removed unused items from `Hasura.Name`; and
5. grouped related names.
Most of the changes are simply changing `G` to `Name`, which I find much more meaningful.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4777
GitOrigin-RevId: a77aa0aee137b2b5e6faec94495d3a9fbfa1348b
## Motivation
This PR rewrites most of Relay to achieve the following:
- ~~fix a bug in which the same node id could refer to two different tables in the schema~~
- remove one of the few remaining uses of the source cache in the schema building code
In doing so, it also:
- simplifies the `BackendSchema` class by removing `node` from it,
- makes it much easier for other backends to support Relay,
- documents, re-organizes, and clarifies the code.
## Description
This PR introduces a new `NodeId` version ~~, and adapts the Postgres code to always generate this V2 version~~. This new id contains the source name, in addition to the table name, in order to disambiguate similar table names across different sources (which is now possible with source customization). In doing so, it now explicitly handles that case for V1 node ids, and returns an explicit error message instead of running the risk of _silently returning the wrong information_.
Furthermore, it adapts `nodeField` to support multiple backends; most of the code was trivial to generalize, and as a result it lowers the cost of entry for other backends, that now only need to support `AFNodeId` in their translation layer.
Finally, it removes one more cycle in the schema building code, by using the same trick we used for remote relationships instead of using the memoization trick of #4576.
## Remaining work
- ~~[ ]write a Changelog entry~~
- ~~[x] adapt all tests that were asserting on an old node id~~
## Future work
This PR was adapted from its original form to avoid a breaking change: while it introduces a Node ID V2, we keep generating V1 IDs and the parser rejects V2 IDs. It will be easy to make the switch at a later data in a subsequent PR.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4593
GitOrigin-RevId: 88e5cb91e8b0646900547fa8c7c0e1463de267a1
This is a first step towards clarifying the role of `UnpreparedValue` as part of the IR. It certainly does not belong in the parser framework.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4588
GitOrigin-RevId: d1582a0b266729b79e00d31057178a4099168e6d
