# `Soundcheck.Check.Warning.UnguardedSubscribe`
[🔗](https://github.com/leonqadirie/soundcheck/blob/v0.1.0/lib/soundcheck/check/warning/unguarded_subscribe.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 `normal` and works with any version of Elixir.

## Explanation

Flags PubSub subscriptions in a LiveView's `mount/3` that are not
guarded by `connected?(socket)`. `mount/3` also runs for the
disconnected HTTP render, in a short-lived process that subscribes,
renders once, and exits; only the connected mount needs the
subscription.

Before:

    def mount(_params, _session, socket) do
      Phoenix.PubSub.subscribe(MyApp.PubSub, "posts")
      {:ok, socket}
    end

After:

    def mount(_params, _session, socket) do
      if connected?(socket), do: Phoenix.PubSub.subscribe(MyApp.PubSub, "posts")
      {:ok, socket}
    end

A call counts as a subscription when its alias-expanded name
(`Phoenix.PubSub.subscribe`, `MyApp.Endpoint.subscribe`) matches
`subscribe_functions`. Calls inside `if connected?(socket)` (or
`unless !connected?(socket)`) are guarded. Subscriptions in helpers
that `mount/3` calls are not followed.

Confidence: high. 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`.

### `:subscribe_functions`

  Regexes or exact names of subscribing functions, as `Module.function`.

*This parameter defaults to* `[~r/^Phoenix\.PubSub\.subscribe$/, ~r/\.subscribe$/]`.

## 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`).

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