graphql-engine/server/src-test/Hasura/Server
Antoine Leblanc cf531b05cb Rewrite Tracing to allow for only one TraceT in the entire stack.
This PR is on top of #7789.

### Description

This PR entirely rewrites the API of the Tracing library, to make `interpTraceT` a thing of the past. Before this change, we ran traces by sticking a `TraceT` on top of whatever we were doing. This had several major drawbacks:
- we were carrying a bunch of `TraceT` across the codebase, and the entire codebase had to know about it
- we needed to carry a second class constraint around (`HasReporterM`) to be able to run all of those traces
- we kept having to do stack rewriting with `interpTraceT`, which went from inconvenient to horrible
- we had to declare several behavioral instances on `TraceT m`

This PR rewrite all of `Tracing` using a more conventional model: there is ONE `TraceT` at the bottom of the stack, and there is an associated class constraint `MonadTrace`: any part of the code that happens to satisfy `MonadTrace` is able to create new traces. We NEVER have to do stack rewriting, `interpTraceT` is gone, and `TraceT` and `Reporter` become  implementation details that 99% of the code is blissfully unaware of: code that needs to do tracing only needs to declare that the monad in which it operates implements `MonadTrace`.

In doing so, this PR revealed **several bugs in the codebase**: places where we were expecting to trace something, but due to the default instance of `HasReporterM IO` we would actually not do anything. This PR also splits the code of `Tracing` in more byte-sized modules, with the goal of potentially moving to `server/lib` down the line.

### Remaining work

This PR is a draft; what's left to do is:
- [x] make Pro compile; i haven't updated `HasuraPro/Main` yet
- [x] document Tracing by writing a note that explains how to use the library, and the meaning of "reporter", "trace" and "span", as well as the pitfalls
- [x] discuss some of the trade-offs in the implementation, which is why i'm opening this PR already despite it not fully building yet
- [x] it depends on #7789 being merged first

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7791
GitOrigin-RevId: cadd32d039134c93ddbf364599a2f4dd988adea8
2023-03-13 17:38:39 +00:00
..
Auth server: update the jwt refresh thread to poll 2023-01-06 06:40:40 +00:00
Init server: use only server context and app env for dependent functions (remove passing of ServeOptions) 2023-02-28 09:11:27 +00:00
Migrate Upgrade Ormolu to v0.5. 2022-11-02 20:55:13 +00:00
AuthSpec.hs Rewrite Tracing to allow for only one TraceT in the entire stack. 2023-03-13 17:38:39 +00:00
CompressionSpec.hs server: don't compress small responses 2022-12-13 17:50:01 +00:00
InitSpec.hs server: use only server context and app env for dependent functions (remove passing of ServeOptions) 2023-02-28 09:11:27 +00:00
TelemetrySpec.hs server, pro: actually reformat the code-base using ormolu 2021-09-23 22:57:37 +00:00
VersionSpec.hs Amend console assets versioning scheme for CE 2022-08-26 12:39:16 +00:00