Merge pull request #34 from andrewvy/feature/add-automated-fetch

Add `mix fetch_cdp_protocol` for fetching & updating new protocols.

Author: andrewvy

lib/mix/tasks/fetch_cdp_protocol.ex

@@ -0,0 +1,54 @@
+defmodule Mix.Tasks.FetchCdpProtocol do
+  @moduledoc """
+  Fetches up-to-date versions of all the Chrome Debugger Protocol files.
+
+  These protocol files are stored in the private storage of this library.
+  """
+
+  use Mix.Task
+
+  @shortdoc "Fetches up-to-date versions of all the Chrome Debugger Protocol files."
+
+  @protocol_sources %{
+    "1-2" => %{
+      url:
+        "https://raw.githubusercontent.com/ChromeDevTools/debugger-protocol-viewer/master/_data/1-2/protocol.json",
+      output: "priv/1-2/protocol.json"
+    },
+    "1-3" => %{
+      url:
+        "https://github.com/ChromeDevTools/debugger-protocol-viewer/blob/master/_data/1-3/protocol.json",
+      output: "priv/1-3/protocol.json"
+    },
+    "tot" => %{
+      url:
+        "https://raw.githubusercontent.com/ChromeDevTools/debugger-protocol-viewer/master/_data/tot/protocol.json",
+      output: "priv/tot/protocol.json"
+    }
+  }
+
+  @temporary_file "protocol.json"
+
+  @impl true
+  def run(_) do
+    Map.keys(@protocol_sources)
+    |> Enum.each(&fetch_protocol/1)
+  end
+
+  def fetch_protocol(version) do
+    protocol_source = Map.fetch!(@protocol_sources, version)
+
+    cmd!("wget #{protocol_source.url}")
+    File.rename(@temporary_file, protocol_source.output)
+  end
+
+  defp cmd!(cmd) do
+    Mix.shell().info([:magenta, "Running: #{cmd}"])
+
+    exit_status = Mix.shell().cmd(cmd)
+
+    if exit_status != 0 do
+      Mix.raise("Non-zero result (#{exit_status}) from command: #{cmd}")
+    end
+  end
+end