Feature: Store hank output in json file

rebar.config

@@ -17,7 +17,8 @@
   {rebar3_format, "~> 1.2.0"},
   {rebar3_lint, "~> 1.1.0"},
   {rebar3_sheldon, "~> 0.4.2"},
-  {rebar3_ex_doc, "~> 0.2.11"}]}.
+  {rebar3_ex_doc, "~> 0.2.11"},
+  {jsx, "~> 3.1.0"}]}.
 
 {dialyzer, [{warnings, [no_return, unmatched_returns, error_handling, underspecs]}]}.
 

src/rebar3_hank_prv.erl

@@ -35,7 +35,13 @@ opts() ->
       $u,
       "unused_ignores",
       boolean,
-      "Warn on unused ignores (default: true)."}].
+      "Warn on unused ignores (default: true)."},
+      {output_json_file,
+        $o,
+        "output_json_file",
+        string,
+        "Output Json File Name (default: empty string)"}
+    ].
 
 %% @private
 -spec do(rebar_state:t()) -> {ok, rebar_state:t()} | {error, iodata()}.
@@ -69,6 +75,7 @@ do(State) ->
           unused_ignores := UnusedIgnores,
           stats := Stats} ->
             instrument(Stats, UnusedIgnores, State),
+            maybe_write_data_to_json_file(Results, State),
             {error, format_results(Results)}
     catch
         Kind:Error:Stack ->
@@ -120,6 +127,80 @@ format_result(#{file := File,
                 text := Msg}) ->
     hank_utils:format_text("~ts:~tp: ~ts", [File, Line, Msg]).
 
+-spec maybe_write_data_to_json_file([hank_rule:result()], rebar_state:t()) -> ok.
+maybe_write_data_to_json_file(Result, State) ->
+    {Args, _} = rebar_state:command_parsed_args(State),
+    case lists:keyfind(output_json_file, 1, Args) of
+        {output_json_file, JsonFilePath} ->
+            case valid_json_format(JsonFilePath) of
+                true ->
+                    ConvertedResult = convert_data_to_binary(Result),
+                    EncodedResult = jsx:encode(ConvertedResult),
+                    ok = file:write_file(JsonFilePath, EncodedResult);
+                false ->
+                    ok
+            end;
+        _ ->
+            ok
+    end.
+
+-spec valid_json_format(string()) -> boolean().
+valid_json_format(JsonFilePath) ->
+    JsonFileName = lists:last(string:tokens(JsonFilePath, "/")),
+    case lists:last(string:tokens(JsonFileName, ".")) of
+        "json" ->
+            true;
+        _ ->
+            false
+    end.
+
+-spec convert_data_to_binary([hank_rule:result()]) -> list().
+convert_data_to_binary(Data) ->
+    Func =
+        fun(RuleDetailMap) ->
+            #{file := FileName, line := Line, rule := RuleBroken, text := Description} = RuleDetailMap,
+            #{
+                <<"path">> => to_binary(FileName),
+                <<"start_line">> => Line,
+                <<"hank_rule_broken">> => to_binary(RuleBroken),
+                <<"title">> => compute_title(RuleBroken),
+                <<"message">> => to_binary(Description)}
+        end,
+    [Func(RuleDetails) || RuleDetails <- Data].
+
+-spec compute_title(atom()) -> binary().
+compute_title(RuleBroken) ->
+    case RuleBroken of
+        unused_macros ->
+            <<"Unused Macros">>;
+        single_use_hrl_attrs ->
+            <<"Macro is only used once">>;
+        unused_record_fields ->
+            <<"Field in the record is unused">>;
+        unused_hrls ->
+            <<"Unused hrl files">>;
+        unused_configuration_options ->
+            <<"Unused config">>;
+        unused_callbacks ->
+            <<"Unused callback functions">>;
+        unnecessary_function_arguments ->
+            <<"Unused function arguments found">>;
+        single_use_hrls ->
+            <<"Hrl is only used once">>
+    end.
+
+to_binary(Input) when is_atom(Input) ->
+    atom_to_binary(Input, utf8);
+to_binary(Input) when is_integer(Input) ->
+    integer_to_binary(Input);
+to_binary(Input) when is_float(Input) ->
+    float_to_binary(Input, [{decimals, 10}, compact]);
+to_binary(Input) when is_list(Input) ->
+    list_to_binary(Input);
+to_binary(Input) when is_pid(Input) ->
+    list_to_binary(pid_to_list(Input));
+to_binary(Input) -> Input.
+
 %% @private
 %% @doc Determines files that should be fully hidden to Hank.
 is_hidden(Filename) ->