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
(Work here originally done by awjchen, rebased and fixed up for merge by
jberryman)
This is part of a merge train towards GHC 9.2 compatibility. The main
issue is the use of the new abstract `KeyMap` in 2.0. See:
https://hackage.haskell.org/package/aeson-2.0.3.0/changelog
Alex's original work is here:
#4305
BEHAVIOR CHANGE NOTE: This change causes a different arbitrary ordering
of serialized Json, for example during metadata export. CLI users care
about this in particular, and so we need to call it out as a _behavior
change_ as we did in v2.5.0. The good news though is that after this
change ordering should be more stable (alphabetical key order).
See: https://hasurahq.slack.com/archives/C01M20G1YRW/p1654012632634389
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4611
Co-authored-by: awjchen <13142944+awjchen@users.noreply.github.com>
GitOrigin-RevId: 700265162c782739b2bb88300ee3cda3819b2e87
## 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
### Description
The main goal of this PR is, as stated, to remove the circular dependency in the schema building code. This cycle arises from the existence of remote relationships: when we build the schema for a source A, a remote relationship might force us to jump to the schema of a source B, or some remote schema. As a result, we end up having to do a dispatch from a "leaf" of the schema, similar to the one done at the root. In turn, this forces us to carry along in the schema a lot of information required for that dispatch, AND it forces us to import the instances in scope, creating an import loop.
As discussed in #4489, this PR implements the "dependency injection" solution: we pass to the schema a function to call to do the dispatch, and to get a generated field for a remote relationship. That way, this function can be chosen at the root level, and the leaves need not be aware of the overall context.
This PR grew a bit bigger than that, however; in an attempt to try and remove the `SourceCache` from the schema altogether, it changed a lot of functions across the schema building code, to thread along the `SourceInfo b` of the source being built. This avoids having to do cache lookups within a given source. A few cases remain, such as relay, that we might try to tackle in a subsequent PR.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4557
GitOrigin-RevId: 9388e48372877520a72a9fd1677005df9f7b2d72
### Description
This PR extends the `RemoteSchema` parsers to also include remote relationships. This include a significant refactoring of the top level schema building blocks, since remote schemas can no longer be built in isolation: they have to be built within the same run of `MonadSchema` as the sources. It is originally taken from the changes in #3069 and was slightly adapted.
I highly recommend turning OFF whitespace in the Github UI for `Schema.hs`, since I've adjusted the indentation of two large functions.
### Warning
Given the lack of a feature flag, this PR technically **enables the feature**. While the metadata API is not plugged in, a savvy user could use `replace_metadata` to set a metadata that contains remote joins from remote schemas, and they would be enabled. Is this acceptable?
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3811
GitOrigin-RevId: a5b00f865cdb8890b0fc02b139c2ebd48929f138
### Description
#3810 was merged with comments still open; this small PR does a few minute clean-ups to address some remaining nits.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3941
GitOrigin-RevId: 3d15eb399828123640a73247b848bc4ddff02c38
### Description
This PR adds the ability to perform remote joins from remote schemas in the engine. To do so, we alter the definition of an `ExecutionStep` targeting a remote schema: the `ExecStepRemote` constructor now expects a `Maybe RemoteJoins`. This new argument is used when processing the execution step, in the transport layer (either `Transport.HTTP` or `Transport.WebSocket`).
For this `Maybe RemoteJoins` to be extracted from a parsed query, this PR also extends the `Execute.RemoteJoin.Collect` module, to implement "collection" from a selection set. Not only do those new functions extract the remote joins, but they also apply all necessary transformations to the selection sets (such as inserting the necessary "phantom" fields used as join keys).
Finally in `Execute.RemoteJoin.Join`, we make two changes. First, we now always look for nested remote joins, regardless of whether the join we just performed went to a source or a remote schema; and second we adapt our join tree logic according to the special cases that were added to deal with remote server edge cases.
Additionally, this PR refactors / cleans / documents `Execute.RemoteJoin.RemoteServer`. This is not required as part of this change and could be moved to a separate PR if needed (a similar cleanup of `Join` is done independently in #3894). It also introduces a draft of a new documentation page for this project, that will be refined in the release PR that ships the feature (either #3069 or a copy of it).
While this PR extends the engine, it doesn't plug such relationships in the schema, meaning that, as of this PR, the new code paths in `Join` are technically unreachable. Adding the corresponding schema code and, ultimately, enabling the metadata API will be done in subsequent PRs.
### Keeping track of concrete type names
The main change this PR makes to the existing `Join` code is to handle a new reserved field we sometimes use when targeting remote servers: the `__hasura_internal_typename` field. In short, a GraphQL selection set can sometimes "branch" based on the concrete "runtime type" of the object on which the selection happens:
```graphql
query {
author(id: 53478) {
... on Writer {
name
articles {
title
}
}
... on Artist {
name
articles {
title
}
}
}
}
```
If both of those `articles` are remote joins, we need to be able, when we get the answer, to differentiate between the two different cases. We do this by asking for `__typename`, to be able to decide if we're in the `Writer` or the `Artist` branch of the query.
To avoid further processing / customization of results, we only insert this `__hasura_internal_typename: __typename` field in the query in the case of unions of interfaces AND if we have the guarantee that we will processing the request as part of the remote joins "folding": that is, if there's any remote join in this branch in the tree. Otherwise, we don't insert the field, and we leave that part of the response untouched.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3810
GitOrigin-RevId: 89aaf16274d68e26ad3730b80c2d2fdc2896b96c
### Description
This PR is one further step towards remote joins from remote schemas. It introduces a custom partial AST to represent queries to remote schemas in the IR: we now need to augment what used to be a straightforward GraphQL AST with additional information for remote join fields.
This PR does the minimal amount of work to adjust the rest of the code accordingly, using `Void` in all places that expect a type representing remote relationships.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3794
GitOrigin-RevId: 33fc317731aace71f82ad158a1951ea93350d6cc
### Description
This PR changes the internal representation of a parsed remote schema. We were still using a list of type definitions, meaning every time we were doing a type lookup we had to iterate through a linked list! 🙀 It was very noticeable on large schemas, that need to do a lot of lookups. This PR consequently changes the internal representation to a HashMap. Building the OneGraph schema on my machine now takes **23 seconds**, compared to **367 seconds** before this patch.
Some important points:
- ~~this PR removes a check for type duplication in remote schemas; it's unclear to me whether that's something we need to add back or not~~ (no longer true)
- this PR makes it obvious that we do not distinguish between "this remote schema is missing type X" and "this remote schema expects type X to be an object, but it's a scalar"; this PR doesn't change anything about it, but adds a comment where we could surface that error (see [2991](https://github.com/hasura/graphql-engine-mono/issues/2991))
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2963
GitOrigin-RevId: f5c96ad40f4e0afcf8cef635b4d64178111f98d3
This commit applies ormolu to the whole Haskell code base by running `make format`.
For in-flight branches, simply merging changes from `main` will result in merge conflicts.
To avoid this, update your branch using the following instructions. Replace `<format-commit>`
by the hash of *this* commit.
$ git checkout my-feature-branch
$ git merge <format-commit>^ # and resolve conflicts normally
$ make format
$ git commit -a -m "reformat with ormolu"
$ git merge -s ours post-ormolu
https://github.com/hasura/graphql-engine-mono/pull/2404
GitOrigin-RevId: 75049f5c12f430c615eafb4c6b8e83e371e01c8e
Remote relationships are now supported on SQL Server and BigQuery. The major change though is the re-architecture of remote join execution logic. Prior to this PR, each backend is responsible for processing the remote relationships that are part of their AST.
This is not ideal as there is nothing specific about a remote join's execution that ties it to a backend. The only backend specific part is whether or not the specification of the remote relationship is valid (i.e, we'll need to validate whether the scalars are compatible).
The approach now changes to this:
1. Before delegating the AST to the backend, we traverse the AST, collect all the remote joins while modifying the AST to add necessary join fields where needed.
1. Once the remote joins are collected from the AST, the database call is made to fetch the response. The necessary data for the remote join(s) is collected from the database's response and one or more remote schema calls are constructed as necessary.
1. The remote schema calls are then executed and the data from the database and from the remote schemas is joined to produce the final response.
### Known issues
1. Ideally the traversal of the IR to collect remote joins should return an AST which does not include remote join fields. This operation can be type safe but isn't taken up as part of the PR.
1. There is a lot of code duplication between `Transport/HTTP.hs` and `Transport/Websocket.hs` which needs to be fixed ASAP. This too hasn't been taken up by this PR.
1. The type which represents the execution plan is only modified to handle our current remote joins and as such it will have to be changed to accommodate general remote joins.
1. Use of lenses would have reduced the boilerplate code to collect remote joins from the base AST.
1. The current remote join logic assumes that the join columns of a remote relationship appear with their names in the database response. This however is incorrect as they could be aliased. This can be taken up by anyone, I've left a comment in the code.
### Notes to the reviewers
I think it is best reviewed commit by commit.
1. The first one is very straight forward.
1. The second one refactors the remote join execution logic but other than moving things around, it doesn't change the user facing functionality. This moves Postgres specific parts to `Backends/Postgres` module from `Execute`. Some IR related code to `Hasura.RQL.IR` module. Simplifies various type class function signatures as a backend doesn't have to handle remote joins anymore
1. The third one fixes partial case matches that for some weird reason weren't shown as warnings before this refactor
1. The fourth one generalizes the validation logic of remote relationships and implements `scalarTypeGraphQLName` function on SQL Server and BigQuery which is used by the validation logic. This enables remote relationships on BigQuery and SQL Server.
https://github.com/hasura/graphql-engine-mono/pull/1497
GitOrigin-RevId: 77dd8eed326602b16e9a8496f52f46d22b795598
This reverts the remote schema type customisation and namespacing feature temporarily as we test for certain conditions.
GitOrigin-RevId: f8ee97233da4597f703970c3998664c03582d8e7
