Add more tests to upload filters

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon/utils.ex

@@ -0,0 +1,25 @@
+# Portions of this file are derived from Pleroma:
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Mobilizon.Utils do
+  @moduledoc """
+  Module that provide generic utils functions for Mobilizon
+  """
+
+  @doc """
+  POSIX-compliant check if command is available in the system
+
+  ## Examples
+      iex> command_available?("git")
+      true
+      iex> command_available?("wrongcmd")
+      false
+
+  """
+  @spec command_available?(String.t()) :: boolean()
+  def command_available?(command) do
+    match?({_output, 0}, System.cmd("sh", ["-c", "command -v #{command}"]))
+  end
+end