Fix postgres errors when running tests

rafael commented

2025-12-03 12:35:11 +01:00

Collaborator

Description of the implemented changes

The changes were:

Bugfixing
New Feature
Breaking Change
Refactoring

By reusing postgres connections when running tests, we avoid running out of them.

What has been changed?

Phoenix.Ecto.SQL.Sandbox Plug (lib/mv_web/endpoint.ex:42-45)

  if Application.compile_env(:mv, :sql_sandbox) do
    plug Phoenix.Ecto.SQL.Sandbox
  end

What it does:

This is a Plug that intercepts every HTTP request during tests
It reads sandbox metadata from the connection's private storage (:ecto_sandbox key)
When it finds this metadata (the owner PID), it calls Ecto.Adapters.SQL.Sandbox.allow/3
to grant the request process and all processes it spawns (including LiveView processes)
permission to use the same database connection as the test
This solves the problem where LiveView processes are started by the Phoenix LiveView
supervisor (not linked to the test process), so they would normally try to checkout their
own connections

Configuration Flag (config/test.exs:49-50)

config :mv, :sql_sandbox, true

What it does:

Sets a compile-time configuration flag that enables the Phoenix.Ecto.SQL.Sandbox plug
only in test environment
Using Application.compile_env/2 ensures this is checked at compile time for better
performance
Prevents the sandbox plug from running in dev/production environments

Definition of Done

Code Quality

No new technical depths
Linting passed
Documentation is added were needed

Accessibility

New elements are properly defined with html-tags
Colour contrast follows WCAG criteria
Aria labels are added when needed
Everything is accessible by keyboard
Tab-Order is comprehensible
All interactive elements have a visible focus

Testing

Tests for new code are written
All tests pass
axe-core dev tools show no critical or major issues

Additional Notes

## Description of the implemented changes The changes were: - [ ] Bugfixing - [ ] New Feature - [ ] Breaking Change - [x] Refactoring By reusing postgres connections when running tests, we avoid running out of them. ## What has been changed? 1. Phoenix.Ecto.SQL.Sandbox Plug (lib/mv_web/endpoint.ex:42-45) ```elixir if Application.compile_env(:mv, :sql_sandbox) do plug Phoenix.Ecto.SQL.Sandbox end ``` What it does: - This is a Plug that intercepts every HTTP request during tests - It reads sandbox metadata from the connection's private storage (:ecto_sandbox key) - When it finds this metadata (the owner PID), it calls Ecto.Adapters.SQL.Sandbox.allow/3 to grant the request process and all processes it spawns (including LiveView processes) permission to use the same database connection as the test - This solves the problem where LiveView processes are started by the Phoenix LiveView supervisor (not linked to the test process), so they would normally try to checkout their own connections 2. Configuration Flag (config/test.exs:49-50) config :mv, :sql_sandbox, true What it does: - Sets a compile-time configuration flag that enables the Phoenix.Ecto.SQL.Sandbox plug only in test environment - Using Application.compile_env/2 ensures this is checked at compile time for better performance - Prevents the sandbox plug from running in dev/production environments ## Definition of Done ### Code Quality - [x] No new technical depths - [x] Linting passed - [ ] Documentation is added were needed ### Accessibility - [ ] New elements are properly defined with html-tags - [ ] Colour contrast follows WCAG criteria - [ ] Aria labels are added when needed - [ ] Everything is accessible by keyboard - [ ] Tab-Order is comprehensible - [ ] All interactive elements have a visible focus ### Testing - [ ] Tests for new code are written - [x] All tests pass - [ ] axe-core dev tools show no critical or major issues ## Additional Notes