Add file watcher for development with live reload (#7)

* Add file watcher for development with live reload
* add linter (credo)
* upgrade Erlang and Elixir versions in CI

.github/workflows/elixir.yaml

@@ -24,8 +24,8 @@ jobs:
       # Specify the OTP and Elixir versions to use when building
       # and running the workflow steps.
       matrix:
-        otp: ['25.3']       # Define the OTP version [required]
-        elixir: ['1.14']    # Define the elixir version [required]
+        otp: ['26.1']       # Define the OTP version [required]
+        elixir: ['1.15']    # Define the elixir version [required]
     steps:
     # Step: Setup Elixir + Erlang image as the base.
     - name: Set up Elixir
@@ -65,22 +65,18 @@ jobs:
           ${{ runner.os }}-mix-${{ env.cache-name }}-
           ${{ runner.os }}-mix-
 
-    # Step: Download project dependencies. If unchanged, uses
-    # the cached version.
+    # If unchanged, uses the cached version.
     - name: Install dependencies
       run: mix deps.get
 
-    # Step: Compile the project treating any warnings as errors.
-    # Customize this step if a different behavior is desired.
     - name: Compiles without warnings
       run: mix compile --warnings-as-errors
 
-    # Step: Check that the checked in code has already been formatted.
-    # This step fails if something was found unformatted.
-    # Customize this step as desired.
     - name: Check Formatting
       run: mix format --check-formatted
 
-    # Step: Execute the tests.
+    - name: Lint
+      run: mix credo
+
     - name: Run tests
       run: mix test --no-start

installer/lib/grf_new/generator.ex

@@ -17,7 +17,7 @@ defmodule Grf.New.Generator do
       {"/config/config.exs", "/config/config.exs"},
 
       {"/lib/app_name.ex", "/lib/#{project.app_name}.ex"},
-      {"/priv/content/index.md", "/priv/content/index.md"},
+      {"/priv/content/index.md", "/src/index.md"},
       {"/priv/layouts/default.html.eex", "/lib/layouts/default.html.eex"},
 
       {"/gitignore", "/.gitignore"},
@@ -54,10 +54,10 @@ defmodule Grf.New.Generator do
 
   defp eex_metadata(project) do
     [
-      griffin_dep: "{:griffin_ssg, \"~> 0.1\"}",
+      griffin_dep: "{:griffin_ssg, \"~> 0.3\"}",
       griffin_github_version_tag: @version,
       output_path: "_site",
-      input_path: "priv",
+      input_path: "src",
       app_module: project.module,
       app_name: project.app_name,
       version: project.version

installer/priv/templates/config/config.exs

@@ -9,7 +9,8 @@ import Config
 
 config :griffin_ssg,
   input_path: "<%= @input_path %>",
-  output_path: "<%= @output_path %>"
+  output_path: "<%= @output_path %>",
+  passthrough_copies: ["assets/*"]
 
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.

installer/priv/templates/mix.exs

@@ -35,7 +35,8 @@ defmodule <%= @app_module %>.MixProject do
   defp deps do
     [
       <%= @griffin_dep %>,
-      {:plug_cowboy, "~> 2.5"}
+      {:plug_live_reload, "~> 0.1"},
+      {:file_system, "~> 1.0", override: true},
     ]
   end
 

installer/priv/templates/priv/content/index.md

@@ -1,6 +1,6 @@
 ---
 title: "<%= @app_name %>"
-layout: "default"
+layout: "default.html"
 ---
 
 Quick static site generation with Elixir templates 🧡

installer/priv/templates/priv/layouts/default.html.eex

@@ -28,7 +28,7 @@
     <h1 class="display-5 fw-bold">Welcome to Griffin!</h1>
     <div class="col-lg-6 mx-auto">
     <p class="lead mb-4">
-      Quick static site generation with Elixir templates 🧡
+      <%%= @content %>
     </p>
     </div>
   </div>

lib/griffin_ssg.ex

@@ -80,10 +80,12 @@ defmodule GriffinSSG do
       assigns
       |> Map.put(:content, content)
       # here we're re-rendering all existing partials when we might only need a very small subset.
-      # TODO render only required partials by looking at args in the quoted expression for `layout`
+      # refactor: render only required partials by looking at args in the quoted expression for `layout`
       |> then(fn current_assigns ->
         if rerender_partials do
           Map.update(current_assigns, :partials, %{}, fn partials ->
+            # refactor: reduce nesting level by pulling parts into separate functions.
+            # credo:disable-for-lines:3
             partials
             |> Enum.map(fn partial ->
               {compiled, _bindings} = Code.eval_quoted(partial, assigns: current_assigns)

lib/griffin_ssg/filesystem.ex

@@ -14,8 +14,7 @@ defmodule GriffinSSG.Filesystem do
   and only some of the files might have been copied.
   """
   def copy_all(files, destination) do
-    ## TODO LOOP OVER FILES AND EITHER CALL CP_R OR CP,
-    ## THIS CODE DOES NOT WORK WITH RELATIVE AND ABSOLUTE PATHS
+    # refactor: this code does not work with both relative and absolute paths.
     files
     |> Enum.flat_map(&list_all(&1))
     |> Enum.reduce({:ok, 0}, fn path, acc ->

lib/griffin_ssg/filesystem/watcher.ex

@@ -0,0 +1,32 @@
+defmodule GriffinSSG.Filesystem.Watcher do
+  @moduledoc """
+  Module for non-named GenServer responsible for watching for changes.
+  Executes a generic callback when file changes are detected.
+  Used for the LiveReload HTTPServer that is launched as part of `mix grf.server`.
+  """
+  use GenServer
+
+  @swap_file_extnames [".swp", ".swx"]
+
+  def start_link([directories, callback]) do
+    GenServer.start_link(__MODULE__, {directories, callback})
+  end
+
+  def init({directories, callback}) do
+    {:ok, pid} = FileSystem.start_link(dirs: directories)
+    FileSystem.subscribe(pid)
+    {:ok, %{callback: callback}}
+  end
+
+  def handle_info({:file_event, _watcher_pid, {file_path, [:modified, :closed]}}, state) do
+    unless Path.extname(file_path) in @swap_file_extnames do
+      state.callback.()
+    end
+
+    {:noreply, state}
+  end
+
+  def handle_info({:file_event, _, _}, state) do
+    {:noreply, state}
+  end
+end

lib/griffin_ssg/layouts.ex

@@ -1,52 +1,14 @@
 defmodule GriffinSSG.Layouts do
+  @moduledoc """
+  Module responsible for compiling layouts. Stores compiled layouts in an ETS table.
+  Supports nested layouts with a maximum nesting depth of 10.
+  """
+
   @layout_extnames [".eex"]
   @layouts_max_nesting_level 10
   @compiled_layouts_table :griffin_build_layouts
   @layout_strings_table :griffin_build_layout_strings
 
-  # def render(layout, options) do
-  #   assigns = Map.get(options, :assigns, %{})
-  #   rerender_partials = Map.get(options, :rerender_partials, true)
-
-  #   content =
-  #     options
-  #     |> Map.fetch!(:content)
-  #     |> EEx.eval_string(assigns: assigns)
-  #     |> then(fn content_string ->
-  #       case Map.get(options, :content_type, ".md") do
-  #         md when md in [".md", ".markdown"] ->
-  #           Earmark.as_html!(content_string)
-
-  #         ".eex" ->
-  #           content_string
-  #       end
-  #     end)
-
-  #   layout_assigns =
-  #     assigns
-  #     |> Map.put(:content, content)
-  #     # here we're re-rendering all existing partials when we might only need a very small subset.
-  #     # TODO render only required partials by looking at args in the quoted expression for `layout`
-  #     |> then(fn current_assigns ->
-  #       if rerender_partials do
-  #         Map.update(current_assigns, :partials, %{}, fn partials ->
-  #           partials
-  #           |> Enum.map(fn partial ->
-  #             {compiled, _bindings} = Code.eval_quoted(partial, assigns: current_assigns)
-  #             compiled
-  #           end)
-  #           |> Enum.into(%{})
-  #         end)
-  #       else
-  #         current_assigns
-  #       end
-  #     end)
-  #     |> Enum.to_list()
-
-  #   {result, _bindings} = Code.eval_quoted(layout, assigns: layout_assigns)
-  #   result
-  # end
-
   def compile_layouts(layouts_dir) do
     try do
       :ets.new(@compiled_layouts_table, [:ordered_set, :public, :named_table])
@@ -223,6 +185,8 @@ defmodule GriffinSSG.Layouts do
 
         pattern =
           Enum.reduce(content_patterns, "<%= @content %>", fn pattern, acc ->
+            # refactor: reduce nesting level by pulling parts into separate functions.
+            # credo:disable-for-next-line
             if String.contains?(parent_layout, pattern) do
               pattern
             else

lib/mix/tasks/grf.build.ex

@@ -392,7 +392,7 @@ defmodule Mix.Tasks.Grf.Build do
         collections =
           opts.collections
           |> Enum.map(fn {collection_name, config} ->
-            # terrible efficiency, we're traversing the parsed list files
+            # refactor: terrible efficiency, we're traversing the parsed list files
             # once per collection. Since most sites will have 1-2 collections max,
             # we're fine with this for now.
             {collection_name,
@@ -404,7 +404,7 @@ defmodule Mix.Tasks.Grf.Build do
 
         tasks =
           for metadata <- parsed_files do
-            # TODO consider setting collections globally on ETS or persistent term
+            # refactor: consider setting collections globally on ETS or persistent term
             Task.Supervisor.async_nolink(
               sup,
               __MODULE__,
@@ -547,8 +547,9 @@ defmodule Mix.Tasks.Grf.Build do
     output
   end
 
+  # refactor: this function shares much of the logic of render_file.
   @doc false
-  def render_file22222(
+  def render_collection_file(
         file,
         %{
           page: page,
@@ -609,7 +610,7 @@ defmodule Mix.Tasks.Grf.Build do
     # render /tags/ page listing all tags
     # render /tags/:tag page listing all pages with that tag
     for {collection_name, collection_values} <- collections do
-      render_file22222(
+      render_collection_file(
         opts.output <> "/#{collection_name}/index.html",
         %{
           page: nil,
@@ -627,7 +628,7 @@ defmodule Mix.Tasks.Grf.Build do
       for {collection_value, collection_value_pages} <- collection_values do
         collection_value = collection_value |> Atom.to_string() |> Slug.slugify()
 
-        render_file22222(
+        render_collection_file(
           opts.output <> "/#{collection_name}/#{collection_value}/index.html",
           %{
             page: nil,
@@ -700,6 +701,8 @@ defmodule Mix.Tasks.Grf.Build do
           |> maybe_parse_csv()
           |> Filesystem.copy_all(opts.output)
           |> then(fn result ->
+            # refactor: reduce nesting level by pulling parts into separate functions.
+            # credo:disable-for-next-line
             case result do
               {:ok, count} -> count
               {:errors, list_errors} -> Mix.raise(hd(list_errors))
@@ -747,10 +750,7 @@ defmodule Mix.Tasks.Grf.Build do
       Mix.shell().info("#{string_col_name}: #{collections_pretty_print}")
 
       for {value, files} <- collections do
-        files_pretty_print =
-          files
-          |> Enum.map(fn metadata -> metadata.input end)
-          |> Enum.join(",")
+        files_pretty_print = Enum.map_join(files, ",", fn metadata -> metadata.input end)
 
         Mix.shell().info("#{string_col_name} #{value}: #{files_pretty_print}")
       end