improvement: use warnings instead of errors for better UX

improvement: move proejct related things to `Project` namespace

documentation/writing-generators.md

@@ -20,7 +20,7 @@ defmodule Mix.Tasks.YourLib.Gen.YourThing do
       ...some_code
     end
     """)
-    |> Igniter.Config.configure(
+    |> Igniter.Project.Config.configure(
       "config.exs",
       app_name,
       [:list_of_things],

lib/install.ex

@@ -43,7 +43,7 @@ defmodule Igniter.Install do
 
               {igniter, [install | install_list]}
             else
-              {Igniter.Deps.add_dependency(igniter, install, requirement,
+              {Igniter.Project.Deps.add_dependency(igniter, install, requirement,
                  error?: true,
                  yes?: "--yes" in argv
                ), [install | install_list]}

lib/project/application.ex

@@ -1,4 +1,4 @@
-defmodule Igniter.Application do
+defmodule Igniter.Project.Application do
   @moduledoc "Codemods and tools for working with Application modules."
 
   require Igniter.Code.Common
@@ -83,11 +83,14 @@ defmodule Igniter.Application do
         zipper
         |> Zipper.down()
         |> Zipper.rightmost()
-        |> Igniter.Code.List.append_new_to_list(to_supervise, diff_checker)
+        |> Igniter.Code.List.append_new_to_list(Macro.escape(to_supervise), diff_checker)
       else
         _ ->
-          {:error,
+          {:warning,
-           "Expected `#{path}` to be an Application with a `start` function that has a `children = [...]` assignment"}
+           """
+           Could not find a `children = [...]` assignment in the `start` function of the `#{application}` module.
+           Please ensure that #{inspect(to_supervise)} is added started by the application `#{application}` manually.
+           """}
       end
     end)
   end
@@ -137,7 +140,19 @@ defmodule Igniter.Application do
           end
 
         _ ->
-          {:error, "Required a module using `Mix.Project` to exist in `mix.exs`"}
+          {:warning,
+           """
+           No module in `mix.exs` using `Mix.Project` was found. Please update your `mix.exs`
+           to point to the application module `#{inspect(application)}`.
+
+           For example:
+
+           def application do
+             [
+               mod: {#{inspect(application)}, []}
+             ]
+           end
+           """}
       end
     end)
   end

lib/project/config.ex

@@ -1,26 +1,47 @@
-defmodule Igniter.Config do
+defmodule Igniter.Project.Config do
   @moduledoc "Codemods and utilities for modifying Elixir config files."
 
   require Igniter.Code.Function
   alias Igniter.Code.Common
   alias Sourceror.Zipper
 
-  @doc "Sets a config value in the given configuration file, if it is not already set."
+  @doc """
-  @spec configure_new(Igniter.t(), Path.t(), atom(), list(atom), term()) :: Igniter.t()
+  Sets a config value in the given configuration file, if it is not already set.
-  def configure_new(igniter, file_path, app_name, config_path, value) do
+
-    configure(igniter, file_path, app_name, config_path, value, &{:ok, &1})
+  ## Opts
+
+  * `failure_message` - A message to display to the user if the configuration change is unsuccessful.
+  """
+  @spec configure_new(Igniter.t(), Path.t(), atom(), list(atom), term(), opts :: Keyword.t()) ::
+          Igniter.t()
+  def configure_new(igniter, file_path, app_name, config_path, value, opts \\ []) do
+    configure(
+      igniter,
+      file_path,
+      app_name,
+      config_path,
+      value,
+      Keyword.put(opts, :updater, &{:ok, &1})
+    )
   end
 
-  @doc "Sets a config value in the given configuration file, updating it with `updater` if it is already set."
+  @doc """
+  Sets a config value in the given configuration file, updating it with `updater` if it is already set.
+
+  ## Opts
+
+  * `:updater` - A function that takes a zipper at a currently configured value and returns a new zipper with the value updated.
+  * `failure_message` - A message to display to the user if the configuration change is unsuccessful.
+  """
   @spec configure(
           Igniter.t(),
           Path.t(),
           atom(),
           list(atom),
           term(),
-          (Zipper.t() -> {:ok, Zipper.t()} | :error) | nil
+          opts :: Keyword.t()
         ) :: Igniter.t()
-  def configure(igniter, file_name, app_name, config_path, value, updater \\ nil) do
+  def configure(igniter, file_name, app_name, config_path, value, opts \\ []) do
     file_contents = "import Config\n"
 
     file_path = Path.join("config", file_name)
@@ -32,7 +53,7 @@ defmodule Igniter.Config do
         value -> Macro.escape(value)
       end
 
-    updater = updater || fn zipper -> {:ok, Common.replace_code(zipper, value)} end
+    updater = opts[:updater] || fn zipper -> {:ok, Common.replace_code(zipper, value)} end
 
     igniter
     |> ensure_default_configs_exist(file_name)
@@ -49,7 +70,7 @@ defmodule Igniter.Config do
                false
            end) do
         nil ->
-          {:error, "No call to `import Config` found in configuration file"}
+          {:warning, bad_config_message(app_name, file_path, config_path, value, opts)}
 
         zipper ->
           modify_configuration_code(zipper, config_path, app_name, value, updater)
@@ -79,6 +100,44 @@ defmodule Igniter.Config do
     """)
   end
 
+  defp bad_config_message(app_name, file_path, config_path, value, opts) do
+    path =
+      config_path
+      |> keywordify(value)
+
+    code =
+      quote do
+        config unquote(app_name), unquote(path)
+      end
+
+    message =
+      if opts[:failure_message] do
+        """
+
+
+        #{opts[:failure_message]}
+        """
+      else
+        ""
+      end
+
+    or_update =
+      if opts[:updater] do
+        " or update"
+      else
+        ""
+      end
+
+    """
+    Please set#{or_update} the following config in #{file_path}:
+
+        #{Macro.to_string(code)}#{String.trim_trailing(message)}
+    """
+  end
+
+  defp keywordify([], value), do: value
+  defp keywordify([key | rest], value), do: [{key, keywordify(rest, value)}]
+
   @doc """
   Modifies elixir configuration code starting at the configured zipper.
 

lib/project/deps.ex

@@ -1,4 +1,4 @@
-defmodule Igniter.Deps do
+defmodule Igniter.Project.Deps do
   @moduledoc "Codemods and utilities for managing dependencies declared in mix.exs"
   require Igniter.Code.Common
   alias Igniter.Code.Common
@@ -100,7 +100,12 @@ defmodule Igniter.Deps do
         Igniter.Code.List.remove_index(zipper, current_declaration_index)
       else
         _ ->
-          {:error, "Failed to remove dependency #{inspect(name)}"}
+          {:warning,
+           """
+           Failed to remove dependency #{inspect(name)} from `mix.exs`.
+
+           Please remove the old dependency manually.
+           """}
       end
     end)
   end

lib/project/formatter.ex

@@ -1,4 +1,4 @@
-defmodule Igniter.Formatter do
+defmodule Igniter.Project.Formatter do
   @moduledoc "Codemods and utilities for interacting with `.formatter.exs` files"
   alias Igniter.Code.Common
   alias Sourceror.Zipper
@@ -43,7 +43,14 @@ defmodule Igniter.Formatter do
               zipper
 
             :error ->
-              zipper
+              {:warning,
+               """
+               Could not import dependency #{inspect(dep)} into `.formatter.exs`.
+
+               Please add the import manually, i.e
+
+                   import_deps: [#{inspect(dep)}]
+               """}
           end
       end
     end)
@@ -87,7 +94,14 @@ defmodule Igniter.Formatter do
               zipper
 
             _ ->
-              zipper
+              {:warning,
+               """
+               Could not add formatter plugin #{inspect(plugin)} into `.formatter.exs`.
+
+               Please add the import manually, i.e
+
+                   plugins: [#{inspect(plugin)}]
+               """}
           end
       end
     end)

test/project/config_test.exs

@@ -1,4 +1,4 @@
-defmodule Igniter.ConfigTest do
+defmodule Igniter.Project.ConfigTest do
   use ExUnit.Case
 
   alias Rewrite.Source
@@ -6,7 +6,7 @@ defmodule Igniter.ConfigTest do
   describe "configure/6" do
     test "it creates the config file if it does not exist" do
       %{rewrite: rewrite} =
-        Igniter.Config.configure(Igniter.new(), "fake.exs", :fake, [:foo, :bar], "baz")
+        Igniter.Project.Config.configure(Igniter.new(), "fake.exs", :fake, [:foo, :bar], "baz")
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -26,7 +26,7 @@ defmodule Igniter.ConfigTest do
 
           config :fake, buz: [:blat]
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [:foo, :bar], "baz")
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:foo, :bar], "baz")
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -41,18 +41,20 @@ defmodule Igniter.ConfigTest do
     test "it merges the spark formatter plugins" do
       %{rewrite: rewrite} =
         Igniter.new()
-        |> Igniter.Config.configure(
+        |> Igniter.Project.Config.configure(
           "fake.exs",
           :spark,
           [:formatter, :"Ash.Resource"],
           [],
-          fn x ->
+          updater: fn x ->
             x
           end
         )
-        |> Igniter.Config.configure("fake.exs", :spark, [:formatter, :"Ash.Domain"], [], fn x ->
+        |> Igniter.Project.Config.configure("fake.exs", :spark, [:formatter, :"Ash.Domain"], [],
+          updater: fn x ->
             x
-        end)
+          end
+        )
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -70,7 +72,7 @@ defmodule Igniter.ConfigTest do
 
           config :fake, buz: [:blat]
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [:foo], "baz")
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:foo], "baz")
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -87,7 +89,7 @@ defmodule Igniter.ConfigTest do
         |> Igniter.create_new_elixir_file("config/fake.exs", """
           import Config
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [Foo.Bar, :bar], "baz")
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [Foo.Bar, :bar], "baz")
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -103,8 +105,8 @@ defmodule Igniter.ConfigTest do
         |> Igniter.create_new_elixir_file("config/fake.exs", """
           import Config
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [Foo.Bar, :bar], "baz")
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [Foo.Bar, :bar], "baz")
-        |> Igniter.Config.configure("fake.exs", :fake, [Foo.Bar, :buz], "biz")
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [Foo.Bar, :buz], "biz")
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -122,7 +124,7 @@ defmodule Igniter.ConfigTest do
 
           config :fake, :buz, [:blat]
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [:foo, :bar], "baz")
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:foo, :bar], "baz")
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -142,7 +144,7 @@ defmodule Igniter.ConfigTest do
 
           config :fake, :buz, [:blat]
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [:foo], "baz")
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:foo], "baz")
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -162,9 +164,11 @@ defmodule Igniter.ConfigTest do
 
           config :fake, :buz, [:blat]
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [:buz], "baz", fn list ->
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:buz], "baz",
+          updater: fn list ->
             Igniter.Code.List.prepend_new_to_list(list, "baz")
-        end)
+          end
+        )
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -183,7 +187,7 @@ defmodule Igniter.ConfigTest do
 
           config :fake, :buz, [:blat]
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [:buz], 12)
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:buz], 12)
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -202,13 +206,15 @@ defmodule Igniter.ConfigTest do
 
           config :fake, foo: %{"a" => ["a", "b"]}
         """)
-        |> Igniter.Config.configure("fake.exs", :fake, [:foo], %{"b" => ["c", "d"]}, fn zipper ->
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:foo], %{"b" => ["c", "d"]},
+          updater: fn zipper ->
             Igniter.Code.Map.set_map_key(zipper, "b", ["c", "d"], fn zipper ->
               with {:ok, zipper} <- Igniter.Code.List.prepend_new_to_list(zipper, "c") do
                 Igniter.Code.List.prepend_new_to_list(zipper, "d")
               end
             end)
-        end)
+          end
+        )
 
       config_file = Rewrite.source!(rewrite, "config/fake.exs")
 
@@ -218,5 +224,24 @@ defmodule Igniter.ConfigTest do
              config :fake, foo: %{"a" => ["a", "b"], "b" => ["c", "d"]}
              """
     end
+
+    test "it presents users with instructions on how to update a malformed config" do
+      %{warnings: [warning]} =
+        Igniter.new()
+        |> Igniter.create_new_elixir_file("config/fake.exs", """
+          config :fake, foo: %{"a" => ["a", "b"]}
+        """)
+        |> Igniter.Project.Config.configure("fake.exs", :fake, [:foo], %{"b" => ["c", "d"]},
+          failure_message: "A failure message!"
+        )
+
+      assert warning == """
+             Please set the following config in config/fake.exs:
+
+                 config :fake, foo: %{"b" => ["c", "d"]}
+
+             A failure message!
+             """
+    end
   end
 end