## Description
This PR implements the GraphQL schema and execution for aggregate
relationships.
In the `schema` crate, the new `model_aggregate_relationship_field`
function handles generating schema for ModelAggregateTarget
relationships. It mostly delegates the meat of its implementation to
reused logic; some refactoring has occurred to make this possible.
This involved changes in `select_many`, `select_aggregate` and
`model_arguments`. The creation of the model arguments field argument
now exists in `model_arguments` and is reused by `select_many` and
`select_aggregate`. The creation of all aggregate field arguments is now
in `select_aggregate::generate_select_aggregate_arguments`, and is then
reused when generating the aggregate relationship field. That field is
annotated with the new `RelationshipToModelAggregate` annotation.
In the `execute` crate, the logic around generating an the aggregate
selection IR was moved from `select_aggregate` into `model_selection`.
This was so it can be reused by the logic in `relationship` that now
uses it to generate an aggregate selection when encountering an
`RelationshipToModelAggregate` field.
Inside `relationship` some rearranging was done so that
`build_local_model_relationship` and `build_remote_relationship` could
work with either a normal model selection IR or the new aggregate
selection IR. The necessitated moving the creation of that IR outside
those functions into the caller, so the different callers can create
different IR (normal vs aggregate IR). This also reduced code
duplication.
New tests have been added to `engine` that cover aggregate relationships
and also remote joined aggregate relationships.
This PR also corrects two bugs in metadata resolve revealed by new
testing:
* The filter input field name in `GraphqlConfig` must be specified if
using an aggregate relationship
* The filter input type name defined on a `Model` must be specified if
that model is the target of an aggregate relationship. Conversely, the
filter input type name can be specified if the `Model` itself doesn't
define an aggregate, but is still involved in a aggregate relationship
(this previously produced an error).
This PR completes the feature, but it is still hidden behind the
experimental flag. There will be a follow up PR to remove that and
expose the functionality by default.
JIRA: [V3ENGINE-160](https://hasurahq.atlassian.net/browse/V3ENGINE-160)
[V3ENGINE-160]:
https://hasurahq.atlassian.net/browse/V3ENGINE-160?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
V3_GIT_ORIGIN_REV_ID: d499371906f7af71a4017c7c3ae75b7693cd3fa7
### What
In order to more easily monitor and review changes to metadata
resolution, this introduces snapshot testing for both successful and
failing calls to `resolve`. I used [Insta](https://insta.rs/) for this.
### How
For tests of the failure case, we already had a text file with the
expected error, so I have turned those files into snapshot files. I
wrote a small script to move the files rather than deleting and
recreating them so I could guarantee that the contents have not changed.
(Unfortunately, Git's diff doesn't always recognise the move as a move
because Insta has added a header.)
For tests of the successful case, I added a line to snapshot the
metadata rather than discarding it.
I also rewrote the tests to use `insta::glob` so we could get rid of
`test_each`.
V3_GIT_ORIGIN_REV_ID: 41bef4cf77bddb8d20d7c101df52ae149e8b0476
## Description
This PR continues on from #725 and adds the metadata resolve logic to
validate the usage of aggregates applied to relationships. The metadata
resolve logic is gated behind a new `enable_aggregate_relationships`
flag and disabled by default.
The new resolve logic lives in
`crates/metadata-resolve/src/stages/relationships/mod.rs`, however, most
of the actual logic that validates the usage of the aggregate expression
with the relationship has been reused from the model aggregate resolve
code. Subsequently, that code
(`crates/metadata-resolve/src/stages/models/aggregation.rs`) was
refactored to return a distinct error type
`ModelAggregateExpressionError` that can be composed with the
`RelationshipError` type, so the same errors can be returned with the
additional context of the relationship they were found in.
New metadata resolve error tests have been added in
`crates/metadata-resolve/tests/failing/aggregate_expression_in_relationship/*`.
Also, two new passing metadata resolve tests have been added to cover
the happy case of root field and relationship aggregate expressions:
`crates/metadata-resolve/tests/passing/aggregate_expressions/*`
JIRA: [V3ENGINE-160](https://hasurahq.atlassian.net/browse/V3ENGINE-160)
[V3ENGINE-160]:
https://hasurahq.atlassian.net/browse/V3ENGINE-160?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
V3_GIT_ORIGIN_REV_ID: 8cd7040cc9277940641d5ac239d7b34f8c1462c5
