move fetch_body!/1 to its own module

lib/mix/tasks/nodelix.install.ex

@@ -30,13 +30,13 @@ defmodule Mix.Tasks.Nodelix.Install do
   def run(args) do
     valid_options = [runtime_config: :boolean, if_missing: :boolean, assets: :boolean]
 
-    {opts, base_url} =
+    {opts, archive_url} =
       case OptionParser.parse_head!(args, strict: valid_options) do
         {opts, []} ->
-          {opts, NodeDownloader.default_base_url()}
+          {opts, NodeDownloader.default_archive_url()}
 
-        {opts, [base_url]} ->
-          {opts, base_url}
+        {opts, [archive_url]} ->
+          {opts, archive_url}
 
         {_, _} ->
           Mix.raise("""
@@ -60,7 +60,7 @@ defmodule Mix.Tasks.Nodelix.Install do
       end
 
       Mix.Task.run("loadpaths")
-      NodeDownloader.install(base_url)
+      NodeDownloader.install(archive_url)
     end
   end
 

lib/nodelix/http_utils.ex

@@ -0,0 +1,96 @@
+defmodule Nodelix.HttpUtils do
+  @moduledoc false
+
+  require Logger
+
+  @spec fetch_body!(String.t()) :: any()
+  def fetch_body!(url) do
+    scheme = URI.parse(url).scheme
+    url = String.to_charlist(url)
+
+    {:ok, _} = Application.ensure_all_started(:inets)
+    {:ok, _} = Application.ensure_all_started(:ssl)
+
+    if proxy = proxy_for_scheme(scheme) do
+      %{host: host, port: port} = URI.parse(proxy)
+      Logger.debug("Using #{String.upcase(scheme)}_PROXY: #{proxy}")
+      set_option = if "https" == scheme, do: :https_proxy, else: :proxy
+      :httpc.set_options([{set_option, {{String.to_charlist(host), port}, []}}])
+    end
+
+    # https://erlef.github.io/security-wg/secure_coding_and_deployment_hardening/inets
+    cacertfile = cacertfile() |> String.to_charlist()
+
+    http_options =
+      [
+        ssl: [
+          verify: :verify_peer,
+          cacertfile: cacertfile,
+          depth: 2,
+          customize_hostname_check: [
+            match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
+          ],
+          versions: protocol_versions()
+        ]
+      ]
+      |> maybe_add_proxy_auth(scheme)
+
+    options = [body_format: :binary]
+
+    case :httpc.request(:get, {url, []}, http_options, options) do
+      {:ok, {{_, 200, _}, _headers, body}} ->
+        body
+
+      other ->
+        raise """
+        Couldn't fetch #{url}: #{inspect(other)}
+
+        This typically means we cannot reach the source or you are behind a proxy.
+        You can try again later and, if that does not work, you might:
+
+          1. If behind a proxy, ensure your proxy is configured and that
+             your certificates are set via the cacerts_path configuration
+
+          2. Manually download the file from the URL above and
+             place it inside "_build/"
+        """
+    end
+  end
+
+  defp proxy_for_scheme("http") do
+    System.get_env("HTTP_PROXY") || System.get_env("http_proxy")
+  end
+
+  defp proxy_for_scheme("https") do
+    System.get_env("HTTPS_PROXY") || System.get_env("https_proxy")
+  end
+
+  defp maybe_add_proxy_auth(http_options, scheme) do
+    case proxy_auth(scheme) do
+      nil -> http_options
+      auth -> [{:proxy_auth, auth} | http_options]
+    end
+  end
+
+  defp proxy_auth(scheme) do
+    with proxy when is_binary(proxy) <- proxy_for_scheme(scheme),
+         %{userinfo: userinfo} when is_binary(userinfo) <- URI.parse(proxy),
+         [username, password] <- String.split(userinfo, ":") do
+      {String.to_charlist(username), String.to_charlist(password)}
+    else
+      _ -> nil
+    end
+  end
+
+  defp cacertfile() do
+    Application.get_env(:nodelix, :cacerts_path) || CAStore.file_path()
+  end
+
+  defp protocol_versions do
+    if otp_version() < 25, do: [:"tlsv1.2"], else: [:"tlsv1.2", :"tlsv1.3"]
+  end
+
+  defp otp_version do
+    :erlang.system_info(:otp_release) |> List.to_integer()
+  end
+end

lib/nodelix/node_downloader.ex

@@ -4,6 +4,8 @@ defmodule Nodelix.NodeDownloader do
 
   require Logger
 
+  alias Nodelix.HttpUtils
+
   @moduledoc false
 
   @doc """
@@ -51,12 +53,7 @@ defmodule Nodelix.NodeDownloader do
     end
   end
 
-  @doc """
-  Returns the path to the archive.
-
-  The archive may not be available if it was not yet installed.
-  """
-  def archive_path do
+  defp archive_path do
     name = "nodejs-#{target()}"
 
     if Code.ensure_loaded?(Mix.Project) do
@@ -66,20 +63,26 @@ defmodule Nodelix.NodeDownloader do
     end
   end
 
+  @spec default_archive_url() :: String.t()
   @doc """
   The default URL to fetch the Node.js archive from.
   """
-  def default_base_url do
+  def default_archive_url do
     "https://nodejs.org/dist/v$version/node-v$version-$target"
   end
 
   @doc """
   Installs Node.js with `configured_version/0`.
   """
-  def install(base_url \\ default_base_url()) do
-    url = get_url(base_url)
+  def install(archive_url \\ default_archive_url()) do
+    fetch_archive(archive_url)
+  end
+
+  defp fetch_archive(archive_url) do
+    url = get_url(archive_url)
     archive_path = archive_path()
-    binary = fetch_body!(url)
+    Logger.debug("Downloading Node.js from #{url}")
+    binary = HttpUtils.fetch_body!(url)
     File.mkdir_p!(Path.dirname(archive_path))
 
     # MacOS doesn't recompute code signing information if a binary
@@ -123,97 +126,6 @@ defmodule Nodelix.NodeDownloader do
     end
   end
 
-  defp fetch_body!(url) do
-    scheme = URI.parse(url).scheme
-    url = String.to_charlist(url)
-    Logger.debug("Downloading Node.js from #{url}")
-
-    {:ok, _} = Application.ensure_all_started(:inets)
-    {:ok, _} = Application.ensure_all_started(:ssl)
-
-    if proxy = proxy_for_scheme(scheme) do
-      %{host: host, port: port} = URI.parse(proxy)
-      Logger.debug("Using #{String.upcase(scheme)}_PROXY: #{proxy}")
-      set_option = if "https" == scheme, do: :https_proxy, else: :proxy
-      :httpc.set_options([{set_option, {{String.to_charlist(host), port}, []}}])
-    end
-
-    # https://erlef.github.io/security-wg/secure_coding_and_deployment_hardening/inets
-    cacertfile = cacertfile() |> String.to_charlist()
-
-    http_options =
-      [
-        ssl: [
-          verify: :verify_peer,
-          cacertfile: cacertfile,
-          depth: 2,
-          customize_hostname_check: [
-            match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
-          ],
-          versions: protocol_versions()
-        ]
-      ]
-      |> maybe_add_proxy_auth(scheme)
-
-    options = [body_format: :binary]
-
-    case :httpc.request(:get, {url, []}, http_options, options) do
-      {:ok, {{_, 200, _}, _headers, body}} ->
-        body
-
-      other ->
-        raise """
-        Couldn't fetch #{url}: #{inspect(other)}
-
-        This typically means we cannot reach the source or you are behind a proxy.
-        You can try again later and, if that does not work, you might:
-
-          1. If behind a proxy, ensure your proxy is configured and that
-             your certificates are set via the cacerts_path configuration
-
-          2. Manually download the executable from the URL above and
-             place it inside "_build/node-#{target()}"
-        """
-    end
-  end
-
-  defp proxy_for_scheme("http") do
-    System.get_env("HTTP_PROXY") || System.get_env("http_proxy")
-  end
-
-  defp proxy_for_scheme("https") do
-    System.get_env("HTTPS_PROXY") || System.get_env("https_proxy")
-  end
-
-  defp maybe_add_proxy_auth(http_options, scheme) do
-    case proxy_auth(scheme) do
-      nil -> http_options
-      auth -> [{:proxy_auth, auth} | http_options]
-    end
-  end
-
-  defp proxy_auth(scheme) do
-    with proxy when is_binary(proxy) <- proxy_for_scheme(scheme),
-         %{userinfo: userinfo} when is_binary(userinfo) <- URI.parse(proxy),
-         [username, password] <- String.split(userinfo, ":") do
-      {String.to_charlist(username), String.to_charlist(password)}
-    else
-      _ -> nil
-    end
-  end
-
-  defp cacertfile() do
-    Application.get_env(:nodelix, :cacerts_path) || CAStore.file_path()
-  end
-
-  defp protocol_versions do
-    if otp_version() < 25, do: [:"tlsv1.2"], else: [:"tlsv1.2", :"tlsv1.3"]
-  end
-
-  defp otp_version do
-    :erlang.system_info(:otp_release) |> List.to_integer()
-  end
-
   defp get_url(base_url) do
     base_url
     |> String.replace("$version", Nodelix.configured_version())