# `Soundcheck.Check.Refactor.StreamCandidate`
[🔗](https://github.com/leonqadirie/soundcheck/blob/v0.1.0/lib/soundcheck/check/refactor/stream_candidate.ex#L1)

## Basics

> #### This check is disabled by default. {: .neutral}
>
> [Learn how to enable it](`e:credo:config_file.html#checks`) via `.credo.exs`.

This check has a base priority of `low` and works with any version of Elixir.

## Explanation

Flags list assigns that handlers grow one item at a time and the
template renders with `:for`. The LiveView keeps the whole list in
memory and resends every item whenever it changes; a stream keeps no
items on the server and sends only the new one.

Before:

    def handle_info({:new_message, message}, socket) do
      {:noreply, update(socket, :messages, &(&1 ++ [message]))}
    end

    <div :for={message <- @messages}>{message.body}</div>

After:

    def handle_info({:new_message, message}, socket) do
      {:noreply, stream_insert(socket, :messages, message)}
    end

    <div id="messages" phx-update="stream">
      <div :for={{id, message} <- @streams.messages} id={id}>{message.body}</div>
    </div>

A write counts as growing the list when `update/3` gets a function
that appends or prepends to its argument (`&(&1 ++ [x])`,
`&[x | &1]`), or `assign/3` gets an append or prepend to
`socket.assigns.key`.

Confidence: low. Tier: syntactic (works without compiling).

## Check-Specific Parameters

Use the following parameters to configure this check:

### `:excluded_paths`

  Paths to skip (atoms, binaries as path segments, or regexes).

*This parameter defaults to* `[~r/\/test\//, "test"]`.

### `:strict`

  Unused.

*This parameter defaults to* `false`.

## General Parameters

Like with all checks, [general params](`e:credo:check_params.html`) can be applied.

Parameters can be configured via the [`.credo.exs` config file](`e:credo:config_file.html`).

---

*Consult [api-reference.md](api-reference.md) for complete listing*