I am going to supply a rough draft to workaround the async live view functions problem.
Hefty disclaimer: this is a hacky workaround and not an elegant solution. The need for this workaround should probably be interpreted as a sign to re-consider the entire approach.
With that said, I am doing this in one of my personal projects.
OK, here we go.
Make this new module:
defmodule MyAppWeb.Utils.LiveViewAsyncUtils do
@moduledoc """
Override the `assign_async` and `start_async`functions from `Phoenix.LiveView`
We do this to allow checking out the `auto` mode Ecto Sandbox in tests.
"""
alias Ecto.Adapters.SQL.Sandbox
alias MyApp.Repo
alias Phoenix.LiveView.Async
def assign_async_aug(socket, key_or_keys, func, opts \\ []) do
func_aug = build_augmented_func(func)
# credo:disable-for-lines:1 MyApp.CustomCredo.Check.Design.NoLiveViewAsyncFunctions
Async.assign_async(socket, key_or_keys, func_aug, opts)
end
def start_async_aug(socket, key_or_keys, func, opts \\ []) do
func_aug = build_augmented_func(func)
# credo:disable-for-lines:1 MyApp.CustomCredo.Check.Design.NoLiveViewAsyncFunctions
Async.start_async(socket, key_or_keys, func_aug, opts)
end
defp build_augmented_func(func) do
parent_pid = self()
fn ->
Sandbox.allow(Repo, parent_pid, self())
func.()
end
end
end
then add this to html_helpers function in my_app_web.ex
import MyAppWeb.Utils.LiveViewAsyncUtils
and then add this credo rule to .credo.exs
{MyApp.CustomCredo.Check.Design.NoLiveViewAsyncFunctions},
and then add that new credo check somewhere in your project
defmodule MyApp.CustomCredo.Check.Design.NoLiveViewAsyncFunctions do
@moduledoc false
use Credo.Check,
base_priority: :high,
category: :design,
explanations: [
check: """
This check ensures that `assign_async` and `start_async` from Phoenix.LiveView.Async
are not used directly in the codebase.
These functions are disallowed because they do not work correctly
in async tests when Sandbox is in auto mode.
"""
]
@doc false
@impl true
def run(%SourceFile{} = source_file, params) do
issue_meta = IssueMeta.for(source_file, params)
Credo.Code.prewalk(source_file, &traverse(&1, &2, issue_meta))
end
# Match full module path: Phoenix.LiveView.Async.assign_async/start_async
defp traverse(
{:., meta, [{:__aliases__, _, [Phoenix, LiveView, Async]}, func]} = ast,
issues,
issue_meta
)
when func in [:assign_async, :start_async] do
{ast, [issue_for(issue_meta, func, meta[:line]) | issues]}
end
# Match aliased form: Async.assign_async/start_async
defp traverse({:., meta, [{:__aliases__, _, [Async]}, func]} = ast, issues, issue_meta)
when func in [:assign_async, :start_async] do
{ast, [issue_for(issue_meta, func, meta[:line]) | issues]}
end
# Match direct function calls: assign_async/start_async (imported)
defp traverse({func, meta, _args} = ast, issues, issue_meta)
when func in [:assign_async, :start_async] do
{ast, [issue_for(issue_meta, func, meta[:line]) | issues]}
end
defp traverse(ast, issues, _issue_meta) do
{ast, issues}
end
defp issue_for(issue_meta, function_name, line_no) do
format_issue(
issue_meta,
message:
"Found disallowed call to Phoenix.LiveView.Async.#{function_name}/3. Use `MyAppWeb.Utils.LiveViewAsyncUtils.#{function_name}_aug/3` instead",
trigger: "#{function_name}",
line_no: line_no
)
end
end
and finally run mix credo to see what needs fixing.
I am not recommending that anybody do this. I only provide the information because I feel responsible for people who followed the OP.
