Add ability to configure individual apps in an umbrella app for enabl…

…ing/disabling Gradient checks

Fix analyzing beam files instead of ex files

Working on unit tests for changes

Fix unit tests

examples/simple_umbrella_app/apps/app_a/lib/app_a_helper.ex

@@ -0,0 +1,9 @@
+defmodule AppAHelper do
+  @moduledoc """
+  Documentation for `AppAHelper`.
+  """
+
+  def help do
+    :here_you_go
+  end
+end

examples/simple_umbrella_app/apps/app_b/lib/app_b_helper.ex

@@ -0,0 +1,9 @@
+defmodule AppBHelper do
+  @moduledoc """
+  Documentation for `AppBHelper`.
+  """
+
+  def help do
+    :here_you_go
+  end
+end

examples/simple_umbrella_app/mix.lock

@@ -1,3 +1,3 @@
 %{
-  "gradualizer": {:git, "https://github.com/josefs/Gradualizer.git", "9e629ade733780113973fe672a51d9650ed0cd86", [ref: "9e629ad"]},
+  "gradualizer": {:git, "https://github.com/josefs/Gradualizer.git", "8b4bf33ffc5596142e690c5aa4f24f2458b9b0fd", [ref: "8b4bf33"]},
 }

lib/mix/tasks/gradient.ex

@@ -7,7 +7,7 @@ defmodule Mix.Tasks.Gradient do
   ## Command-line options
 
     * `--no-compile` - do not compile even if needed
-    * `--no-ex-check` - do not perform checks specyfic for Elixir
+    * `--no-ex-check` - do not perform checks specific for Elixir
       (from ElixirChecker module)
     * `--no-gradualizer-check` - do not perform the Gradualizer checks
     * `--no-specify` - do not specify missing lines in AST what can
@@ -19,9 +19,10 @@ defmodule Mix.Tasks.Gradient do
     * `--infer` - infer type information from literals and other language
       constructs,
     * `--verbose` - show what Gradualizer is doing
+    * `--print-filenames` - print the name of every file being analyzed (mainly useful for tests)
     * `--no-fancy` - do not use fancy error messages
     * `--fmt-location none` - do not display location for easier comparison
-    * `--fmt-location brief` - display location for machine processing 
+    * `--fmt-location brief` - display location for machine processing
     * `--fmt-location verbose` - display location for human readers (default)
 
     * `--no-colors` - do not use colors in printed messages
@@ -36,6 +37,8 @@ defmodule Mix.Tasks.Gradient do
 
   use Mix.Task
 
+  alias Gradient.ElixirFileUtils
+
   @options [
     # skip phases options
     no_compile: :boolean,
@@ -48,6 +51,7 @@ defmodule Mix.Tasks.Gradient do
     stop_on_first_error: :boolean,
     infer: :boolean,
     verbose: :boolean,
+    print_filenames: :boolean,
     # formatter options
     no_fancy: :boolean,
     fmt_location: :string,
@@ -70,7 +74,11 @@ defmodule Mix.Tasks.Gradient do
     # Compile the project before the analysis
     maybe_compile_project(options)
     # Get paths to files
-    files = get_paths(user_paths)
+    files = get_paths(user_paths) |> filter_enabled_paths()
+
+    if options[:print_filenames] do
+      print_filenames(files)
+    end
 
     IO.puts("Typechecking files...")
 
@@ -84,6 +92,32 @@ defmodule Mix.Tasks.Gradient do
     :ok
   end
 
+  defp print_filenames(files) do
+    IO.puts("Files to check:")
+
+    cwd = File.cwd!() <> "/"
+    # Range for slicing off cwd from the beginning of a string
+    cwd_range = String.length(cwd)..-1
+
+    Enum.each(files, fn {app, filenames} ->
+      # Print app name
+      case app do
+        "apps/" <> appname -> IO.puts("Files in app #{appname}:")
+        # May be nil for non-umbrella apps
+        _ -> :noop
+      end
+
+      # Print actual filenames
+      for filename <- filenames do
+        # Convert charlist to string
+        filename = to_string(filename)
+        # If the filename starts with the cwd, don't print the cwd
+        filename = if String.starts_with?(filename, cwd), do: String.slice(filename, cwd_range), else: filename
+        IO.puts(filename)
+      end
+    end)
+  end
+
   defp execute(stream, opts) do
     res = if opts[:crash_on_error], do: stream, else: Enum.to_list(stream)
 
@@ -213,4 +247,98 @@ defmodule Mix.Tasks.Gradient do
   defp compile_path(app_name) do
     Mix.Project.build_path() <> "/lib/" <> to_string(app_name) <> "/ebin"
   end
+
+  @spec filter_enabled_paths(map()) :: map()
+  def filter_enabled_paths(apps_paths) do
+    apps_paths
+    |> Enum.map(fn {app_name, app_files} ->
+      {app_name, filter_paths_for_app(app_name, app_files)}
+    end)
+    |> Map.new()
+  end
+
+  defp filter_paths_for_app(app_name, app_files) do
+    config = gradient_config_for_app(app_name)
+
+    enabled? = Keyword.get(config, :enabled, true)
+    file_overrides_enabled? = Keyword.get(config, :file_overrides, enabled?)
+
+    if file_overrides_enabled? do
+      magic_comment =
+        if enabled?, do: "# gradient:disable-for-file", else: "# gradient:enable-for-file"
+
+      filter_files_with_magic_comment(app_name, app_files, magic_comment, not enabled?)
+    else
+      if enabled?, do: app_files, else: []
+    end
+  end
+
+  defp gradient_config_for_app(app) do
+    app_config = mix_config_for_app(app)[:gradient] || []
+
+    if Mix.Project.umbrella?() do
+      # Merge in config from umbrella app
+      umbrella_config = Mix.Project.config()[:gradient] || []
+      Keyword.merge(umbrella_config, app_config)
+    else
+      app_config
+    end
+  end
+
+  defp path_for_app(nil), do: ""
+  defp path_for_app(app_name), do: app_name <> "/"
+
+  defp mix_config_for_app(nil), do: Mix.Project.config()
+
+  defp mix_config_for_app(app) do
+    # Read the file looking for a "defmodule" to get the module name of the app's mixfile
+    mixfile_module_str =
+      File.stream!(path_for_app(app) <> "mix.exs")
+      |> Enum.find(&String.starts_with?(&1, "defmodule"))
+      |> (fn a -> Regex.run(~r/defmodule ([\w.]+)/, a) end).()
+      |> Enum.at(1)
+
+    mixfile_module = String.to_atom("Elixir." <> mixfile_module_str)
+
+    # return the module's config
+    mixfile_module.project()
+  end
+
+  defp filter_files_with_magic_comment(app_name, beam_files, comment, should_include?) do
+    app_path = path_for_app(app_name) |> Path.expand()
+    deps_path = Path.expand(mix_config_for_app(app_name)[:deps_path] || "deps")
+
+    Enum.filter(beam_files, fn beam_path ->
+      # Given the path to a .beam file, find out the .ex source file path
+      ex_path =
+        ex_filename_from_beam(beam_path)
+        # Turn the relative path into absolute
+        |> Path.expand(app_path)
+
+      # Filter out any paths representing code generated by deps
+      is_dep = String.starts_with?(ex_path, deps_path)
+
+      # Filter out the files with the magic comment
+      has_magic_comment? =
+        File.stream!(ex_path)
+        |> Enum.any?(fn line -> String.trim(line) == comment end)
+
+      # Negate has_magic_comment? if should_include? is false
+      has_magic_comment? = if should_include?, do: has_magic_comment?, else: not has_magic_comment?
+
+      has_magic_comment? and not is_dep
+    end)
+  end
+
+  defp ex_filename_from_beam(beam_path) do
+    case ElixirFileUtils.get_forms(beam_path) do
+      {:ok, [{:attribute, _, :file, {filename, _}} | _]} ->
+        # Convert the *.beam compiled filename to its corresponding *.ex source file
+        # (it's a charlist initially so we pipe it through to_string)
+        filename |> to_string()
+
+      error ->
+        raise "Error resolving .ex filename from compiled .beam filename #{inspect(beam_path)}: #{inspect(error)}"
+    end
+  end
 end