Skip Erlang modules that have empty docs (#1383)

lib/ex_doc/language/erlang.ex

@@ -6,6 +6,10 @@ defmodule ExDoc.Language.Erlang do
   alias ExDoc.{Autolink, Refs}
 
   @impl true
+  def module_data(_module, {:docs_v1, _, _, _, doc, _, _}, _config) when not is_map(doc) do
+    :skip
+  end
+
   def module_data(module, docs_chunk, _config) do
     ":" <> id = inspect(module)
     abst_code = get_abstract_code(module)

test/ex_doc/retriever/erlang_test.exs

@@ -75,9 +75,20 @@ defmodule ExDoc.Retriever.ErlangTest do
       assert function2.specs == []
     end
 
+    @tag :otp23
+    @tag :otp24
+    test "module with no docs is skipped", c do
+      erlc(c, :mod, ~S"""
+      -module(mod).
+      """)
+
+      [] = Retriever.docs_from_modules([:mod], %ExDoc.Config{})
+    end
+
     @tag :otp24
     test "callbacks", c do
       erlc(c, :mod, ~S"""
+      %% @doc Docs.
       -module(mod).
 
       -callback callback1() -> atom().
@@ -91,15 +102,14 @@ defmodule ExDoc.Retriever.ErlangTest do
       assert callback1.id == "c:callback1/0"
       assert callback1.type == :callback
       assert DocAST.to_string(callback1.doc) == "callback1/0 docs."
-      assert Path.basename(callback1.source_url) == "mod.erl:3"
-      # this is an edoc bug, it should be 4
-      assert callback1.doc_line == 3
+      assert Path.basename(callback1.source_url) == "mod.erl:4"
       assert Erlang.autolink_spec(hd(callback1.specs), []) == "callback1() -> atom()."
     end
 
     @tag :otp24
     test "types", c do
       erlc(c, :mod, ~S"""
+      %% @doc Docs.
       -module(mod).
       -export_type([type1/0, opaque1/0]).