Improve Phoenix integration (#281)

* add phoenix scope utils

* refactor source to be more readable

* add phoenix plugin

* phoenix goto def

* improve scopes module readability

* remove redundant `is_list/1` guard

* define `suggestions/4` only on elixir versions >= 1.14.0

* require elixir >=1.14 to run tests

* fixup! require elixir >=1.14 to run tests

* add @moduledoc false

* expand variables and module attributes on scope

* fixup! expand variables and module attributes on scope

* fixup! expand variables and module attributes on scope

---------

Co-authored-by: Gustavo Aguiar <[email protected]>

lib/elixir_sense/core/source.ex

@@ -400,25 +400,26 @@ defmodule ElixirSense.Core.Source do
 
     # TODO refactor to use Macro.path on elixir 1.14
     with {:ok, ast} <- NormalizedCode.Fragment.container_cursor_to_quoted(prefix, columns: true),
-         {_, {:ok, call, npar, meta, options, cursor_at_option, option}} <-
-           Macro.prewalk(ast, nil, &find_call_pre/2),
-         {{m, elixir_prefix}, f} when f not in @excluded_funs <- get_mod_fun(call, binding_env) do
+         {_, {:ok, call_info}} <- Macro.prewalk(ast, nil, &find_call_pre/2),
+         {{m, elixir_prefix}, f} when f not in @excluded_funs <-
+           get_mod_fun(call_info.call, binding_env) do
       %{
         candidate: {m, f},
         elixir_prefix: elixir_prefix,
-        npar: npar,
-        pos: {{meta[:line], meta[:column]}, {meta[:line], nil}},
-        cursor_at_option: cursor_at_option,
-        options_so_far: options,
-        option: option
+        params: call_info.params,
+        npar: call_info.npar,
+        pos: {{call_info.meta[:line], call_info.meta[:column]}, {call_info.meta[:line], nil}},
+        cursor_at_option: call_info.cursor_at_option,
+        options_so_far: call_info.options,
+        option: call_info.option
       }
     else
       _ -> nil
     end
   end
 
-  def find_call_pre(ast, {:ok, call, npar, meta, options, cursor_at_option, option}),
-    do: {ast, {:ok, call, npar, meta, options, cursor_at_option, option}}
+  def find_call_pre(ast, {:ok, call_info}),
+    do: {ast, {:ok, call_info}}
 
   # transform `a |> b(c)` calls into `b(a, c)`
   def find_call_pre({:|>, _, [params_1, {call, meta, params_rest}]}, state) do
@@ -440,20 +441,45 @@ defmodule ElixirSense.Core.Source do
   defp find_cursor_in_params(params, call, meta) do
     case Enum.reverse(params) do
       [{:__cursor__, _, []} | rest] ->
-        {:ok, call, length(rest), meta, [], :maybe, nil}
+        {:ok,
+         %{
+           call: call,
+           params: Enum.reverse(rest),
+           npar: length(rest),
+           meta: meta,
+           options: [],
+           cursor_at_option: :maybe,
+           option: nil
+         }}
 
       [keyword_list | rest] when is_list(keyword_list) ->
         case Enum.reverse(keyword_list) do
           [{:__cursor__, _, []} | kl_rest] ->
             if Keyword.keyword?(kl_rest) do
-              {:ok, call, length(rest), meta, Enum.reverse(kl_rest) |> Enum.map(&elem(&1, 0)),
-               true, nil}
+              {:ok,
+               %{
+                 call: call,
+                 params: Enum.reverse(rest),
+                 npar: length(rest),
+                 meta: meta,
+                 options: Enum.reverse(kl_rest) |> Enum.map(&elem(&1, 0)),
+                 cursor_at_option: true,
+                 option: nil
+               }}
             end
 
           [{atom, {:__cursor__, _, []}} | kl_rest] when is_atom(atom) ->
             if Keyword.keyword?(kl_rest) do
-              {:ok, call, length(rest), meta, Enum.reverse(kl_rest) |> Enum.map(&elem(&1, 0)),
-               false, atom}
+              {:ok,
+               %{
+                 call: call,
+                 params: Enum.reverse(rest),
+                 npar: length(rest),
+                 meta: meta,
+                 options: Enum.reverse(kl_rest) |> Enum.map(&elem(&1, 0)),
+                 cursor_at_option: false,
+                 option: atom
+               }}
             end
 
           _ ->
@@ -504,6 +530,10 @@ defmodule ElixirSense.Core.Source do
   def get_mod_fun([atom, fun], _binding_env) when is_atom(atom), do: {{atom, false}, fun}
   def get_mod_fun(_, _binding_env), do: nil
 
+  def get_mod([{:__aliases__, _, list} | _rest], binding_env) do
+    get_mod(list, binding_env)
+  end
+
   def get_mod([{:__MODULE__, _, nil} | rest], binding_env) do
     if binding_env.current_module not in [nil, Elixir] do
       mod =

lib/elixir_sense/plugins/phoenix.ex

@@ -0,0 +1,105 @@
+defmodule ElixirSense.Plugins.Phoenix do
+  @moduledoc false
+
+  @behaviour ElixirSense.Plugin
+
+  use ElixirSense.Providers.Suggestion.GenericReducer
+
+  alias ElixirSense.Core.Source
+  alias ElixirSense.Core.Binding
+  alias ElixirSense.Core.Introspection
+  alias ElixirSense.Core.ModuleStore
+  alias ElixirSense.Plugins.Phoenix.Scope
+  alias ElixirSense.Plugins.Util
+  alias ElixirSense.Providers.Suggestion.Matcher
+
+  @phoenix_route_funcs ~w(
+    get put patch trace
+    delete head options
+    forward connect post
+  )a
+
+  @impl true
+  def setup(context) do
+    ModuleStore.ensure_compiled(context, Phoenix.Router)
+  end
+
+  if Version.match?(System.version(), ">= 1.14.0") do
+    @impl true
+    def suggestions(hint, {Phoenix.Router, func, 1, _info}, _list, opts)
+        when func in @phoenix_route_funcs do
+      binding = Binding.from_env(opts.env, opts.buffer_metadata)
+      {_, scope_alias} = Scope.within_scope(opts.cursor_context.text_before, binding)
+
+      case find_controllers(opts.module_store, opts.env, hint, scope_alias) do
+        [] -> :ignore
+        controllers -> {:override, controllers}
+      end
+    end
+
+    def suggestions(
+          hint,
+          {Phoenix.Router, func, 2, %{params: [_path, module]}},
+          _list,
+          opts
+        )
+        when func in @phoenix_route_funcs do
+      binding_env = Binding.from_env(opts.env, opts.buffer_metadata)
+      {_, scope_alias} = Scope.within_scope(opts.cursor_context.text_before)
+      {module, _} = Source.get_mod([module], binding_env)
+
+      module = Module.safe_concat(scope_alias, module)
+
+      suggestions =
+        for {export, {2, :function}} when export not in ~w(action call)a <-
+              Introspection.get_exports(module),
+            name = inspect(export),
+            Matcher.match?(name, hint) do
+          %{
+            type: :generic,
+            kind: :function,
+            label: name,
+            insert_text: Util.trim_leading_for_insertion(hint, name),
+            detail: "Phoenix action"
+          }
+        end
+
+      {:override, suggestions}
+    end
+  end
+
+  @impl true
+  def suggestions(_hint, _func_call, _list, _opts) do
+    :ignore
+  end
+
+  defp find_controllers(module_store, env, hint, scope_alias) do
+    [prefix | _] =
+      env.module
+      |> inspect()
+      |> String.split(".")
+
+    for module <- module_store.list,
+        mod_str = inspect(module),
+        Util.match_module?(mod_str, prefix),
+        mod_str =~ "Controller",
+        Util.match_module?(mod_str, hint) do
+      {doc, _} = Introspection.get_module_docs_summary(module)
+
+      %{
+        type: :generic,
+        kind: :class,
+        label: mod_str,
+        insert_text: skip_scope_alias(scope_alias, mod_str),
+        detail: "Phoenix controller",
+        documentation: doc
+      }
+    end
+    |> Enum.sort_by(& &1.label)
+  end
+
+  defp skip_scope_alias(nil, insert_text), do: insert_text
+
+  defp skip_scope_alias(scope_alias, insert_text),
+    do: String.replace_prefix(insert_text, "#{inspect(scope_alias)}.", "")
+end

lib/elixir_sense/plugins/phoenix/scope.ex

@@ -0,0 +1,110 @@
+defmodule ElixirSense.Plugins.Phoenix.Scope do
+  @moduledoc false
+
+  alias ElixirSense.Core.Source
+  alias ElixirSense.Core.Binding
+
+  import Module, only: [safe_concat: 2, safe_concat: 1]
+
+  def within_scope(buffer, binding_env \\ %Binding{}) do
+    {:ok, ast} = Code.Fragment.container_cursor_to_quoted(buffer)
+
+    with {true, scopes_ast} <- get_scopes(ast),
+         scopes_ast = Enum.reverse(scopes_ast),
+         scope_alias <- get_scope_alias(scopes_ast, binding_env) do
+      {true, scope_alias}
+    end
+  end
+
+  defp get_scopes(ast) do
+    path = Macro.path(ast, &match?({:__cursor__, _, _}, &1))
+
+    scopes =
+      path
+      |> Enum.filter(&match?({:scope, _, _}, &1))
+      |> Enum.map(fn {:scope, meta, params} ->
+        params = Enum.reject(params, &match?([{:do, _} | _], &1))
+        {:scope, meta, params}
+      end)
+
+    case scopes do
+      [] -> {false, nil}
+      scopes -> {true, scopes}
+    end
+  end
+
+  defp get_scope_alias(scopes_ast, binding_env, module \\ nil)
+
+  # is this possible? scope do ... end
+  defp get_scope_alias([{:scope, _, []}], _binding_env, module), do: module
+
+  # scope "/" do ... end
+  defp get_scope_alias([{:scope, _, [scope_params]}], _binding_env, module)
+       when not is_list(scope_params),
+       do: module
+
+  # scope path: "/", alias: ExampleWeb do ... end
+  defp get_scope_alias([{:scope, _, [scope_params]}], binding_env, module) do
+    scope_alias = Keyword.get(scope_params, :alias)
+    scope_alias = get_mod(scope_alias, binding_env)
+    safe_concat(module, scope_alias)
+  end
+
+  # scope "/", alias: ExampleWeb do ... end
+  defp get_scope_alias(
+         [{:scope, _, [_scope_path, scope_params]}],
+         binding_env,
+         module
+       )
+       when is_list(scope_params) do
+    scope_alias = Keyword.get(scope_params, :alias)
+    scope_alias = get_mod(scope_alias, binding_env)
+    safe_concat(module, scope_alias)
+  end
+
+  # scope "/", ExampleWeb do ... end
+  defp get_scope_alias(
+         [{:scope, _, [_scope_path, scope_alias]}],
+         binding_env,
+         module
+       ) do
+    scope_alias = get_mod(scope_alias, binding_env)
+    safe_concat(module, scope_alias)
+  end
+
+  # scope "/", ExampleWeb, host: "api." do ... end
+  defp get_scope_alias(
+         [{:scope, _, [_scope_path, scope_alias, _scope_params]}],
+         binding_env,
+         module
+       ) do
+    scope_alias = get_mod(scope_alias, binding_env)
+    safe_concat(module, scope_alias)
+  end
+
+  # recurse
+  defp get_scope_alias([head | tail], binding_env, module) do
+    scope_alias = get_scope_alias([head], binding_env, module)
+    safe_concat([module, scope_alias, get_scope_alias(tail, binding_env)])
+  end
+
+  defp get_mod({:__aliases__, _, [scope_alias]}, binding_env) do
+    get_mod(scope_alias, binding_env)
+  end
+
+  defp get_mod({name, _, nil}, binding_env) when is_atom(name) do
+    case Binding.expand(binding_env, {:variable, name}) do
+      {:atom, atom} ->
+        atom
+
+      _ ->
+        nil
+    end
+  end
+
+  defp get_mod(scope_alias, binding_env) do
+    with {mod, _} <- Source.get_mod([scope_alias], binding_env) do
+      mod
+    end
+  end
+end

lib/elixir_sense/providers/definition.ex

@@ -13,8 +13,10 @@ defmodule ElixirSense.Providers.Definition do
   alias ElixirSense.Core.State.ModFunInfo
   alias ElixirSense.Core.State.TypeInfo
   alias ElixirSense.Core.State.VarInfo
+  alias ElixirSense.Core.Source
   alias ElixirSense.Core.SurroundContext
   alias ElixirSense.Location
+  alias ElixirSense.Plugins.Phoenix.Scope
 
   @doc """
   Finds out where a module, function, macro or variable was defined.
@@ -174,14 +176,7 @@ defmodule ElixirSense.Providers.Definition do
       scope: scope
     } = env
 
-    m =
-      case module do
-        {:atom, a} ->
-          a
-
-        _ ->
-          nil
-      end
+    m = get_module(module, context, env, metadata)
 
     case {m, function}
          |> Introspection.actual_mod_fun(
@@ -249,4 +244,23 @@ defmodule ElixirSense.Providers.Definition do
         end
     end
   end
+
+  defp get_module(module, %{end: {line, col}}, env, metadata) do
+    with {true, module} <- get_phoenix_module(module, env) do
+      text_before = Source.text_before(metadata.source, line, col)
+
+      case Scope.within_scope(text_before) do
+        {false, _} -> module
+        {true, scope_alias} -> Module.safe_concat(scope_alias, module)
+      end
+    end
+  end
+
+  defp get_phoenix_module(module, env) do
+    case {Phoenix.Router in env.requires, module} do
+      {true, {:atom, module}} -> {true, module}
+      {false, {:atom, module}} -> module
+      _ -> nil
+    end
+  end
 end

test/elixir_sense/definition_test.exs

@@ -14,6 +14,27 @@ defmodule ElixirSense.Providers.DefinitionTest do
     assert nil == ElixirSense.definition("__MODULE__", 1, 1)
   end
 
+  @tag requires_elixir_1_14: true
+  test "find module definition inside Phoenix's scope" do
+    _define_existing_atom = ExampleWeb
+
+    buffer = """
+    defmodule ExampleWeb.Router do
+      import Phoenix.Router
+
+      scope "/", ExampleWeb do
+        get "/", PageController, :home
+      end
+    end
+    """
+
+    %Location{type: :module, file: file, line: line, column: column} =
+      ElixirSense.definition(buffer, 5, 15)
+
+    assert file =~ "elixir_sense/test/support/plugins/phoenix/page_controller.ex"
+    assert read_line(file, {line, column}) =~ "ExampleWeb.PageController"
+  end
+
   test "find definition of aliased modules in `use`" do
     buffer = """
     defmodule MyModule do