add benchmark facilities (#2107)

- Add Mix.Tasks.Benchmark
- Add Sequin.Bench.Stats

Tested and working with `--through reorder_buffer` and `--through sps`

Author: acco

AGENTS.md

@@ -46,6 +46,12 @@ These commands should pass before committing. Warnings or noise in test is not a
 - For fast feedback, run `mix test --exclude unboxed`. This skips synchronous tests. Then run `mix test` at the end to validate your work.
 - New tests that you create MUST NOT generate extra logs, even if the tests pass.
 
+## Testing
+
+### No `Process.sleep`
+
+Process.sleep is not allowed in test. You can use temporarily to get things working. But then find a way to use signal passing or telemetry handlers to get rid of it.
+
 ## Using jj workspaces for isolated work
 
 When working on a feature or fix, you can create an isolated workspace using jj:

config/bench.exs

@@ -0,0 +1,31 @@
+import Config
+
+config :sequin, Oban, testing: :manual, prefix: "sequin_config"
+
+config :sequin, Sequin.Repo,
+  username: "postgres",
+  password: "postgres",
+  hostname: "localhost",
+  database: "sequin_bench",
+  stacktrace: true,
+  show_sensitive_data_on_connection_error: true,
+  pool_size: 50
+
+config :sequin, Sequin.Vault,
+  ciphers: [
+    default: {
+      Cloak.Ciphers.AES.GCM,
+      tag: "AES.GCM.V1", key: Base.decode64!("ZTu2hzCwKYbeNea+8+Y2p0CBXpWusF6agpsZlQsVVi0="), iv_length: 12
+    }
+  ]
+
+config :sequin, SequinWeb.Endpoint,
+  http: [ip: {127, 0, 0, 1}, port: 4002],
+  secret_key_base: "erV7XavfZn9wH6ZOort1IThbuZRv6q3FrG5JjgQfCqe9dyVLkKmi1yxZ9X2DaUy4",
+  server: false
+
+config :sequin,
+  env: :bench,
+  ecto_repos: [Sequin.Repo]
+
+config :swoosh, :api_client, false

config/runtime.exs

@@ -36,6 +36,7 @@ metrics_auth =
       ]
   end
 
+config :sequin, Sequin.Benchmark.Stats, track_messages: System.get_env("BENCHMARK_TRACK_MESSAGES") == "true"
 config :sequin, :metrics_basic_auth, metrics_auth
 
 if System.get_env("PORT") do