fix crash on invalid multialias

Author: lukaszsamson

apps/language_server/lib/language_server/providers/definition/locator.ex

@@ -129,7 +129,8 @@ defmodule ElixirLS.LanguageServer.Providers.Definition.Locator do
                    {:., _, [{:__aliases__, _, _}, :{}]} -> true
                    _ -> false
                  end) do
-              [{:., _, [{:__aliases__, _, outer_alias}, :{}]} | _] ->
+              [{:., _, [{:__aliases__, _, outer_alias = [head | _]}, :{}]} | _]
+              when is_atom(head) ->
                 # Combine outer alias with the one under cursor
                 expanded = Module.concat(outer_alias ++ [alias])
 
@@ -141,6 +142,29 @@ defmodule ElixirLS.LanguageServer.Providers.Definition.Locator do
                   binding_env
                 )
 
+              [{:., _, [{:__aliases__, _, [{:__MODULE__, _, _} | outer_alias_rest]}, :{}]} | _] ->
+                # Combine __MODULE__ with the one under cursor
+                expanded = Module.concat([module | outer_alias_rest] ++ [alias])
+
+                find_function_or_module(
+                  {{:atom, expanded}, nil},
+                  context,
+                  env,
+                  metadata,
+                  binding_env
+                )
+
+              [{:., _, [{:__MODULE__, _, _}, :{}]} | _] ->
+                expanded = Module.concat([module] ++ [alias])
+
+                find_function_or_module(
+                  {{:atom, expanded}, nil},
+                  context,
+                  env,
+                  metadata,
+                  binding_env
+                )
+
               _ ->
                 find_function_or_module(
                   {{:atom, alias}, nil},

apps/language_server/lib/language_server/providers/hover/docs.ex

@@ -162,11 +162,21 @@ defmodule ElixirLS.LanguageServer.Providers.Hover.Docs do
                    {:., _, [{:__aliases__, _, _}, :{}]} -> true
                    _ -> false
                  end) do
-              [{:., _, [{:__aliases__, _, outer_alias}, :{}]} | _] ->
+              [{:., _, [{:__aliases__, _, outer_alias = [head | _]}, :{}]} | _]
+              when is_atom(head) ->
                 # Combine outer alias with the one under cursor
                 expanded = Module.concat(outer_alias ++ [alias])
                 mod_fun_docs({{:atom, expanded}, nil}, context, binding_env, env, metadata)
 
+              [{:., _, [{:__aliases__, _, [{:__MODULE__, _, _} | outer_alias_rest]}, :{}]} | _] ->
+                # Combine __MODULE__ with the one under cursor
+                expanded = Module.concat([module | outer_alias_rest] ++ [alias])
+                mod_fun_docs({{:atom, expanded}, nil}, context, binding_env, env, metadata)
+
+              [{:., _, [{:__MODULE__, _, _}, :{}]} | _] ->
+                expanded = Module.concat([module] ++ [alias])
+                mod_fun_docs({{:atom, expanded}, nil}, context, binding_env, env, metadata)
+
               _ ->
                 mod_fun_docs({{:atom, alias}, nil}, context, binding_env, env, metadata)
             end

apps/language_server/lib/language_server/providers/references/locator.ex

@@ -222,11 +222,21 @@ defmodule ElixirLS.LanguageServer.Providers.References.Locator do
                    {:., _, [{:__aliases__, _, _}, :{}]} -> true
                    _ -> false
                  end) do
-              [{:., _, [{:__aliases__, _, outer_alias}, :{}]} | _] ->
+              [{:., _, [{:__aliases__, _, outer_alias = [head | _]}, :{}]} | _]
+              when is_atom(head) ->
                 # Combine outer alias with the one under cursor
                 expanded = Module.concat(outer_alias ++ [alias])
                 refs_for_mod_fun.({{:atom, expanded}, nil})
 
+              [{:., _, [{:__aliases__, _, [{:__MODULE__, _, _} | outer_alias_rest]}, :{}]} | _] ->
+                # Combine __MODULE__ with the one under cursor
+                expanded = Module.concat([module | outer_alias_rest] ++ [alias])
+                refs_for_mod_fun.({{:atom, expanded}, nil})
+
+              [{:., _, [{:__MODULE__, _, _}, :{}]} | _] ->
+                expanded = Module.concat([module] ++ [alias])
+                refs_for_mod_fun.({{:atom, expanded}, nil})
+
               _ ->
                 refs_for_mod_fun.({{:atom, alias}, nil})
             end