## Description
This change adds support for querying into nested arrays in Data Connector agents that support such a concept (currently MongoDB).
### DC API changes
- New API type `ColumnType` which allows representing the type of a "column" as either a scalar type, an object reference or an array of `ColumnType`s. This recursive definition allows arbitrary nesting of arrays of types.
- The `type` fields in the API types `ColumnInfo` and `ColumnInsertSchema` now take a `ColumnType` instead of a `ScalarType`.
- To ensure backwards compatibility, a `ColumnType` representing a scalar serialises and deserialises to the same representation as `ScalarType`.
- In queries, the `Field` type now has a new constructor `NestedArrayField`. This contains a nested `Field` along with optional `limit`, `offset`, `where` and `order_by` arguments. (These optional arguments are not yet used by either HGE or the MongoDB agent.)
### MongoDB Haskell agent changes
- The `/schema` endpoint will now recognise arrays within the JSON validation schema and generate corresponding arrays in the DC schema.
- The `/query` endpoint will now handle `NestedArrayField`s within queries (although it does not yet handle `limit`, `offset`, `where` and `order_by`).
### HGE server changes
- The `Backend` type class adds a new type family `XNestedArrays b` to enable nested arrays on a per-backend basis (currently enabled only for the `DataConnector` backend.
- Within `RawColumnInfo` the column type is now represented by a new type `RawColumnType b` which mirrors the shape of the DC API `ColumnType`, but uses `XNestedObjects b` and `XNestedArrays b` type families to allow turning nested object and array supports on or off for a particular backend. In the `DataConnector` backend `API.CustomType` is converted into `RawColumnInfo 'DataConnector` while building the schema.
- In the next stage of schema building, the `RawColumnInfo` is converted into a `StructuredColumnInfo` which allows us to represent the three different types of columns: scalar, object and array. TODO: the `StructuredColumnInfo` looks very similar to the Logical Model types. The main difference is that it uses the `XNestedObjects` and `XNestedArrays` type families. We should be able to combine these two representations.
- The `StructuredColumnInfo` is then placed into a `FIColumn` `FieldInfo`. This involved some refactoring of `FieldInfo` as I had previously split out `FINestedObject` into a separate constructor. However it works out better to represent all "column" fields (i.e. scalar, object and array) using `FIColumn` as this make it easier to implement permission checking correctly. This is the reason the `StructuredColumnInfo` was needed.
- Next, the `FieldInfo` are used to generate `FieldParser`s. We add a new constructor to `AnnFieldG` for `AFNestedArray`. An `AFNestedArray` field parser can contain either a simple array selection or an array aggregate. Simple array `FieldParsers` are currently limited to subfield selection. We will add support for limit, offset, where and order_by in a future PR. We also don't yet generate array aggregate `FieldParsers.
- The new `AFNestedArray` field is handled by the `QueryPlan` module in the `DataConnector` backend. There we generate an `API.NestedArrayField` from the AFNestedArray. We also handle nested arrays when reshaping the response from the DC agent.
## Limitations
- Support for limit, offset, filter (where) and order_by is not yet fully implemented, although it should not be hard to add this
- Support for aggregations on nested arrays is not yet fully implemented
- Permissions involving nested arrays (and objects) not yet implemented
- This should be integrated with Logical Model types, but that will happen in a separate PR
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/9149
GitOrigin-RevId: 0e7b71a994fc1d2ca1ef73bfe7b96e95b5328531
## Description
This change adds support for nested object fields in HGE IR and Schema Cache, the Data Connectors backend and API, and the MongoDB agent.
### Data Connector API changes
- The `/schema` endpoint response now includes an optional set of GraphQL type definitions. Table column types can refer to these definitions by name.
- Queries can now include a new field type `object` which contains a column name and a nested query. This allows querying into a nested object within a field.
### MongoDB agent changes
- Add support for querying into nested documents using the new `object` field type.
### HGE changes
- The `Backend` type class has a new type family `XNestedObjects b` which controls whether or not a backend supports querying into nested objects. This is currently enabled only for the `DataConnector` backend.
- For backends that support nested objects, the `FieldInfo` type gets a new constructor `FINestedObject`, and the `AnnFieldG` type gets a new constructor `AFNestedObject`.
- If the DC `/schema` endpoint returns any custom GraphQL type definitions they are stored in the `TableInfo` for each table in the source.
- During schema cache building, the function `addNonColumnFields` will check whether any column types match custom GraphQL object types stored in the `TableInfo`. If so, they are converted into `FINestedObject` instead of `FIColumn` in the `FieldInfoMap`.
- When building the `FieldParser`s from `FieldInfo` (function `fieldSelection`) any `FINestedObject` fields are converted into nested object parsers returning `AFNestedObject`.
- The `DataConnector` query planner converts `AFNestedObject` fields into `object` field types in the query sent to the agent.
## Limitations
### HGE not yet implemented:
- Support for nested arrays
- Support for nested objects/arrays in mutations
- Support for nested objects/arrays in order-by
- Support for filters (`where`) in nested objects/arrays
- Support for adding custom GraphQL types via track table metadata API
- Support for interface and union types
- Tests for nested objects
### Mongo agent not yet implemented:
- Generate nested object types from validation schema
- Support for aggregates
- Support for order-by
- Configure agent port
- Build agent in CI
- Agent tests for nested objects and MongoDB agent
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7844
GitOrigin-RevId: aec9ec1e4216293286a68f9b1af6f3f5317db423
Basic MongoDB agent. This is intended as a starting point for playing with nested documents in a MongoDB back end. Currently supports basic queries with projections, where expressions, limit and offset. No support for joins, aggregates or mutations.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7840
GitOrigin-RevId: 3f03b8416c95acf2b68da1db56cbe36a513a4bde
- In a previous PR we made more use of `common` stanzas, but these require `cabal-version: 2.2` (so some of those stanzas were not functional before this PR). This just bumps the `cabal-version`s straight to 3.6, which is the latest version we support in CI, where we build with cabal 3.6.
- This `cabal-version` upgrade required fixing a few `license` fields, from `BSD3` to `BSD-3-Clause`. I've also added `default-language` fields where appropriate, although this is perhaps optional.
- Using cabal's [syntax for applying options to all _local_ packages](https://cabal.readthedocs.io/en/3.8/cabal-project.html#package-configuration-options), we unify the cabal configuration, and apply `-Werror` to all local packages, which wasn't the case until now.
- Applying `-Werror` to all local packages required a few additional exceptions to the warnings that were switched on in hasura/graphql-engine-mono#7614.
- Deleted SCM links to the original pool library.
Overall, the effect of this PR is:
- more warnings
- stricter compilation
- ~~less cabal configuration~~
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7730
GitOrigin-RevId: 592e9e46d103bcc8726df5b745306bd9f77f7efc
See [Enable all the warnings](https://medium.com/mercury-bank/enable-all-the-warnings-a0517bc081c3). This PR follows that approach, except that it re-disables those warnings that would prevent a successful build.
There are some newer warning flags that older GHC versions don't recognize. So this also updates some of our CI routines to the GHC version that we're currently using for `graphql-engine` itself, namely 9.2.5. I don't see a reason to keep testing those libraries against older GHC versions.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7614
GitOrigin-RevId: d48a6db09dab29616e273549d0045f98ecb4586f
### Description
This fixes the libs' test config: without that line, hspec fails to run at build time. I haven't tried actually running the tests now that they build, fwiw.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7694
GitOrigin-RevId: 03d7bc969c4bd195e84080d50f1f6441a1d8d50f
