* allow altering type of a column iff session vars are defined in permissions
* use a sum type to define dependency reason
* set jwt expiry test's expiry time to 4 seconds
* derive Data instance for necessary types to simplify 'hasStaticExp'
query templates is a little known feature that lets you template rql
queries and serve them as rest apis. This is not relevant anymore
given the GraphQL interface and getting rid of it reduces the dev
time when adding features in few subsystems.
This feature has never been used outside hasura's internal projects or
documented or exposed through console and hence can safely be removed.
Currently, we allow tracking of a table with the same name as an already tracked function, and vice-versa. This causes an issue when querying from GraphQL since it will only query the table and not the function. I've made changes to disallow this by throwing an error.
Changes compared to `/v1alpha1/graphql`
* Changed all graphql responses in **/v1/graphql** endpoint to be 200. All graphql clients expect responses to be HTTP 200. Non-200 responses are considered transport layer errors.
* Errors in http and websocket layer are now consistent and have similar structure.
Examples
1) `
pytest --hge-urls "http://127.0.0.1:8080" --pg-urls "postgresql://admin@127.0.0.1:5432/hge_tests" -vv
`
2) `pytest --hge-urls "http://127.0.0.1:8080" "http://127.0.0.1:8081" --pg-urls "postgresql://admin@127.0.0.1:5432/hge_tests" "postgresql://admin@127.0.0.1:5432/hge_tests2" -vv
`
### Solution and Design
<!-- How is this issue solved/fixed? What is the design? -->
<!-- It's better if we elaborate -->
#### Reducing execution time of tests
- The Schema setup and teardown, which were earlier done per test method, usually takes around 1 sec.
- For mutations, the model has now been changed to only do schema setup and teardown once per test class.
- A data setup and teardown will be done once per test instead (usually takes ~10ms).
- For the test class to get this behaviour, one can can extend the class `DefaultTestMutations`.
- The function `dir()` should be define which returns the location of the configuration folder.
- Inside the configuration folder, there should be
- Files `<conf_dir>/schema_setup.yaml` and `<conf_dir>/schema_teardown.yaml`, which has the metadata query executed during schema setup and teardown respectively
- Files named `<conf_dir>/values_setup.yaml` and `<conf_dir>/values_teardown.yaml`. These files are executed to setup and remove data from the tables respectively.
#### Running Graphql queries on both http and websockets
- Each GraphQL query/mutation is run on the both HTTP and websocket protocols
- Pytests test parameterisation is used to achieve this
- The errors over websockets are slightly different from that on HTTP
- The code takes care of converting the errors in HTTP to errors in websockets
#### Parallel executation of tests.
- The plugin pytest-xdist helps in running tests on parallel workers.
- We are using this plugin to group tests by file and run on different workers.
- Parallel test worker processes operate on separate postgres databases(and separate graphql-engines connected to these databases). Thus tests on one worker will not affect the tests on the other worker.
- With two workers, this decreases execution times by half, as the tests on event triggers usually takes a long time, but does not consume much CPU.
From `alpha-40` we've been using a `WHERE` clause to fetch required rows and generate mutation response. This has a few limitations like the requirement of a primary key/unique constraint. This also returns inconsistent data on `delete` mutation as mentioned in #1794.
Now, we're using `VALUES (..)` (refer [here](https://www.postgresql.org/docs/current/sql-values.html)) expression to form virtual table rows in `SQL` to generate mutation response.
Internal changes:-
- Not to use primary key/unique constraint columns:-
- Revert back to `ConstraintName` from `TableConstraint` in `TableInfo` type
- Remove `tcCols` field in `TableConstraint` type
- Modify `table_info.sql` and `fetchTableMeta` function `SQL`
- A test case to perform `delete` mutation and returning relational objects.
1. Haskel library `pg-client-hs` has been updated to expose a function that helps listen to `postgres` notifications over a `channel` in this [PR](https://github.com/hasura/pg-client-hs/pull/5)
2. The server records an event in a table `hdb_catalog.hdb_cache_update_event` whenever any `/v1/query` (that changes metadata) is requested. A trigger notifies a `cache update` event via `hasura_cache_update` channel
3. The server runs two concurrent threads namely `listener` and `processor`. The `listener` thread listens to events on `hasura_cache_update` channel and pushed into a `Queue`. The `processor` thread fetches events from that `Queue` and processes it. Thus server rebuilds schema cache from database and updates.
If returning field contains nested selections then mutation is performed in two steps
1. Mutation is performed with returning columns of any primary key and unique constraints
2. returning fields are queried on rows returned by selecting from table by filtering with column values returned in Step 1.
Since mutation takes two courses based on selecting relations in returning field, it is hard to maintain sequence of prepared arguments (PrepArg) generated while resolving returning field. So, we're using txtConverter instead of prepare to resolve mutation fields.
* support jsonb and geometry operators on RQL bool exps, close#1408
* add tests for jsonb operators in /v1/query
TODO:-
-> add tests for geometry (postgis) operators
* support parsing session variables for st_d_within and has_key ops
-> Add tests for boolExp operators and select permissions
* improve parsing $st_d_within op's json value logic
