[#141943791] Markdown support

.gitignore

@@ -14,3 +14,4 @@ log/
 *_plt
 .DS_Store
 doc/
+_elixir_build/

README.md

@@ -51,6 +51,7 @@ This is the format (see [sheldon_config.erl](https://github.com/inaka/sheldon/bl
 #{ ignore_words    => [string()]
  , ignore_patterns => [regex()]
  , ignore_blocks   => [ignore_block()]
+ , adapters        => [adapter()]
  }.
 ```
 Then, if we call the previous `sheldon:check/1` but with configuration we can skip the error
@@ -60,6 +61,29 @@ Then, if we call the previous `sheldon:check/1` but with configuration we can sk
 ok
 ```
 
+## Adapters
+
+Sometimes we have to check the spelling of formatted text but `sheldon` handles it as a plain text so we will face problems with that.
+One example is `markdown` files, if we try to check them `sheldon` will complain about things like '##' or '\*something\*'.
+For these cases `sheldon` provides `adapters`. An adapter is an Erlang module with an `adapt/1` function which will receive a line in `binary()` format and returns that line transformed.
+For example, `sheldon` provides [markdown_adapter](https://github.com/inaka/sheldon/blob/master/src/adapter/markdown_adapter.erl) which converts from `markdown` to plain text.
+
+In order to use them we only have to declare them in the config file:
+
+```erlang
+#{adapters => [markdown_adapter]}.
+```
+
+You can create your own adapter which fits your requirements, you only need to respect the `adapt/1` function signature.
+
+```erlang
+-spec adapt(binary()) -> iodata().
+adapt(Line) ->
+  ...
+```
+
+You can add all the adapters you want and they will be executed in order.
+
 ## Examples
 Check [this](examples/README.md) out.
 
@@ -76,3 +100,4 @@ Check [this](examples/README.md) out.
 
 - Erlang/OTP 19+ in order to use it.
 - Erlang/OTP 19.0.2+ in order to test it.
+- Elixir "~> 1.4"

elvis.config

@@ -5,7 +5,8 @@
     {config,
      [#{dirs => ["src", "test"],
         filter => "*.erl",
-        ruleset => erl_files
+        ruleset => erl_files,
+        rules => [{elvis_style, line_length, #{limit => 100}}]
        },
       #{dirs => ["."],
         filter => "Makefile",

rebar.config

@@ -21,6 +21,7 @@
 %% == Dependencies ==
 
 {deps, [
+  {earmark, {elixir, "earmark" ,"1.2.0"}}
 ]}.
 
 %% == Profiles ==
@@ -85,3 +86,19 @@
   {base_plt_location, "."},
   {base_plt_prefix, "sheldon"}
 ]}.
+
+%% == Plugins ==
+{plugins, [
+  { rebar3_elixir_compile, ".*", {git, "https://github.com/barrel-db/rebar3_elixir_compile.git", {ref, "1c6c516"}}}
+]}.
+
+{provider_hooks, [
+  {pre, [{compile, {ex, compile}}]},
+  {pre, [{release, {ex, compile}}]}
+]}.
+
+{elixir_opts,
+  [
+    {env, dev}
+  ]
+}.

rebar.lock

@@ -1 +1,4 @@
-[].
+[{<<"bunt">>,{elixir,"bunt","0.2.0"},2},
+ {<<"credo">>,{elixir,"credo","0.7.2"},1},
+ {<<"dialyxir">>,{elixir,"dialyxir","0.5.0"},1},
+ {<<"earmark">>,{elixir,"earmark","1.2.0"},0}].

src/adapter/html_adapter.erl

@@ -0,0 +1,73 @@
+%%% @doc HTML Adapter. *Note* This is not the final version of html_adapter, currently it only
+%%% escapes tags and replace some special html characters.
+%%%
+%%% Copyright 2017 Inaka <[email protected]>
+%%%
+%%% Licensed under the Apache License, Version 2.0 (the "License");
+%%% you may not use this file except in compliance with the License.
+%%% You may obtain a copy of the License at
+%%%
+%%%     http://www.apache.org/licenses/LICENSE-2.0
+%%%
+%%% Unless required by applicable law or agreed to in writing, software
+%%% distributed under the License is distributed on an "AS IS" BASIS,
+%%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%%% See the License for the specific language governing permissions and
+%%% limitations under the License.
+%%% @end
+%%% @copyright Inaka <[email protected]>
+%%%
+-module(html_adapter).
+-author("Felipe Ripoll <[email protected]>").
+
+%% API
+-export([adapt/1]).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+
+-spec adapt(binary()) -> iodata().
+adapt(Line) ->
+  Line1 = escape_tags(Line),
+  replace_chars(Line1).
+
+%%%===================================================================
+%%% Internal Functions
+%%%===================================================================
+
+-spec replace_chars(binary()) -> iodata().
+replace_chars(Line) ->
+  Chars = chars_to_replace(),
+  replace_chars(Line, Chars).
+
+-spec replace_chars(iodata(), [{string(), string()}]) -> iodata().
+replace_chars(Line, []) ->
+  Line;
+replace_chars(Line, [{Pattern, ReplaceBy} | Rest]) ->
+  Result = re:replace(Line, Pattern, ReplaceBy),
+  Result2 = replace(Result, Line, {Pattern, ReplaceBy}),
+  replace_chars(Result2, Rest).
+
+-spec escape_tags(iodata()) -> iodata().
+escape_tags(Line) ->
+  Pattern = "<[^>]*>",
+  ReplaceBy = "",
+  Result = re:replace(Line, Pattern, ReplaceBy),
+  replace(Result, Line, {Pattern, ReplaceBy}).
+
+-spec replace(iodata(), iodata(), {string(), string()}) -> iodata().
+replace(Line, Line, _) ->
+  Line;
+replace([Line, []], _, _) ->
+  Line;
+replace(Line, _PreviousLine, {Pattern, ReplaceBy}) ->
+  Result = re:replace(Line, Pattern, ReplaceBy),
+  replace(Result, Line, {Pattern, ReplaceBy}).
+
+-spec chars_to_replace() -> [{string(), string()}].
+chars_to_replace() ->
+  [ {"&quot;", "\""}
+  , {"&amp;", "&"}
+  , {"&lt;", "<"}
+  ].

src/adapter/markdown_adapter.erl

@@ -0,0 +1,36 @@
+%%% @doc Markdown Adapter.
+%%%
+%%% Copyright 2017 Inaka <[email protected]>
+%%%
+%%% Licensed under the Apache License, Version 2.0 (the "License");
+%%% you may not use this file except in compliance with the License.
+%%% You may obtain a copy of the License at
+%%%
+%%%     http://www.apache.org/licenses/LICENSE-2.0
+%%%
+%%% Unless required by applicable law or agreed to in writing, software
+%%% distributed under the License is distributed on an "AS IS" BASIS,
+%%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%%% See the License for the specific language governing permissions and
+%%% limitations under the License.
+%%% @end
+%%% @copyright Inaka <[email protected]>
+%%%
+-module(markdown_adapter).
+-author("Felipe Ripoll <[email protected]>").
+
+%% API
+-export([adapt/1]).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+
+-spec adapt(binary()) -> iodata().
+adapt(Line) ->
+  {ok, Line1, _} = 'Elixir.Earmark':as_html(Line),
+  % Earmark replace ' by ’ and ‘ which causes a bitstring, so we replace it by ' again
+  Line2 = binary:replace(Line1, [<<226, 128, 152>>, <<226, 128, 153>>], <<39>>, [global]),
+  % replace “ and ” by "
+  Line3 = binary:replace(Line2, [<<226, 128, 156>>, <<226, 128, 157>>], <<34>>, [global]),
+  html_adapter:adapt(Line3).

src/sheldon.app.src

@@ -5,7 +5,9 @@
   {registered, []},
   {applications, [
     kernel,
-    stdlib
+    stdlib,
+    elixir,
+    earmark
   ]},
   {modules, []},
   {mod, {sheldon_app, []}},