Merge pull request #260 from inaka/jfacorro.152.max_module_length

[Closes #152] Max module length rule

src/elvis_style.erl

@@ -17,7 +17,8 @@
          module_naming_convention/3,
          state_record_and_type/3,
          no_spec_with_records/3,
-         dont_repeat_yourself/3
+         dont_repeat_yourself/3,
+         max_module_length/3
         ]).
 
 -define(LINE_LENGTH_MSG, "Line ~p is too long: ~s.").
@@ -86,6 +87,10 @@
         "The code in the following (LINE, COL) locations has "
         "the same structure: ~s.").
 
+-define(MAX_MODULE_LENGTH,
+        "The code for module ~p has ~p lines which exceeds the "
+        "maximum of ~p.").
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Rules
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -377,6 +382,31 @@ dont_repeat_yourself(Config, Target, RuleConfig) ->
             lists:map(ResultFun, Nodes)
     end.
 
+-spec max_module_length(elvis_config:config(),
+                        elvis_file:file(),
+                        empty_rule_config()) ->
+    [elvis_result:item()].
+max_module_length(Config, Target, RuleConfig) ->
+    MaxLength = maps:get(max_length, RuleConfig, 500),
+    IgnoreModules = maps:get(ignore, RuleConfig, []),
+
+    {Root, _} = elvis_file:parse_tree(Config, Target),
+    {Src, _} = elvis_file:src(Target),
+
+    ModuleName = elvis_code:module_name(Root),
+    Lines = binary:split(Src, <<"\n">>, [global, trim]),
+    Ignored = lists:member(ModuleName, IgnoreModules),
+
+    case length(Lines) of
+        L when L > MaxLength, not Ignored ->
+            Info = [ModuleName, L, MaxLength],
+            Msg = ?MAX_MODULE_LENGTH,
+            Result = elvis_result:new(item, Msg, Info, 0),
+            [Result];
+        _ ->
+            []
+    end.
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Private
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

test/examples/fail_max_module_length.erl

@@ -0,0 +1,15 @@
+-module(fail_max_module_length).
+
+-export([f/1]).
+
+
+
+
+
+
+
+
+
+
+
+f(_) -> ok.

test/examples/fail_operator_spaces.erl

@@ -39,8 +39,8 @@ tag_filters(DocName, #{conn := Conn} = State) ->
          "ORDER BY tag_name "],
   Values = [],
   case {Conn, Sql, Values} of
-    {ok, Maps} ->
+    {ok, Maps, _} ->
       {ok, {raw, Maps}, State};
-    {error, Error} ->
+    {error, Error, _} ->
       {error, Error, State}
   end.

test/style_SUITE.erl

@@ -24,7 +24,9 @@
          verify_state_record_and_type/1,
          verify_no_spec_with_records/1,
          verify_dont_repeat_yourself/1,
-         verify_order_line_results/1
+         verify_max_module_length/1,
+         %% Non-rule
+         results_are_ordered_by_line/1
         ]).
 
 -define(EXCLUDED_FUNS,
@@ -333,8 +335,24 @@ verify_dont_repeat_yourself(_Config) ->
     {ok, FilePass} = elvis_test_utils:find_file(SrcDirs, PathPass),
     [] = elvis_style:dont_repeat_yourself(ElvisConfig, FilePass, RuleConfig5).
 
--spec verify_order_line_results(config()) -> any().
-verify_order_line_results(_Config) ->
+-spec verify_max_module_length(config()) -> any().
+verify_max_module_length(_Config) ->
+    ElvisConfig = elvis_config:default(),
+    SrcDirs = elvis_config:dirs(ElvisConfig),
+
+    PathFail = "fail_max_module_length.erl",
+    {ok, FileFail} = elvis_test_utils:find_file(SrcDirs, PathFail),
+    RuleConfig = #{max_length => 10},
+    [_] = elvis_style:max_module_length(ElvisConfig, FileFail, RuleConfig),
+
+    RuleConfig1 = #{max_length => 14},
+    [_] = elvis_style:max_module_length(ElvisConfig, FileFail, RuleConfig1),
+
+    RuleConfig2 = #{max_length => 15},
+    [] = elvis_style:max_module_length(ElvisConfig, FileFail, RuleConfig2).
+
+-spec results_are_ordered_by_line(config()) -> any().
+results_are_ordered_by_line(_Config) ->
     ElvisConfig = elvis_config:default(),
     {fail, Results} = elvis:rock(ElvisConfig),
     true = lists:all(fun(X) -> X end, is_item_line_sort(Results)).
@@ -358,4 +376,4 @@ is_list_sort([#{line_num := Line1} | T1]) ->
     case Line1 =< Line2 of
         true -> is_list_sort(T1);
         false -> false
-    end.
+    end.