[#60] Add support and docs for a YML erlang_ls.config file

README.md

@@ -98,6 +98,22 @@ Code completion is available for the following elements:
 * Atom names
 * Module attributes
 
+## Customization
+
+It is possible to customize the behaviour of the `erlang_ls` server by
+adding a `erlang_ls.config` file to the root of your projects.
+
+A sample `erlang_ls.config` file would look like the following:
+
+    otp_path: "/path/to/otp/lib/erlang"
+
+Currently, the following customizations are possible:
+
+| Parameter | Description                  |
+|-----------|------------------------------|
+| otp_path  | Path to the OTP installation |
+|           |                              |
+
 ## Troubleshooting
 
 It is possible to compile and start the language server in _debug mode_:

rebar.config

@@ -12,6 +12,7 @@
        , {cowlib, "2.3.0"}
        , {redbug, "1.2.1"}
        , {lager,  "3.6.8"}
+       , {yamerl, "0.7.0"}
        ]
 }.
 

rebar.lock

@@ -4,13 +4,15 @@
  {<<"jsx">>,{pkg,<<"jsx">>,<<"2.9.0">>},0},
  {<<"lager">>,{pkg,<<"lager">>,<<"3.6.8">>},0},
  {<<"ranch">>,{pkg,<<"ranch">>,<<"1.5.0">>},0},
- {<<"redbug">>,{pkg,<<"redbug">>,<<"1.2.1">>},0}]}.
+ {<<"redbug">>,{pkg,<<"redbug">>,<<"1.2.1">>},0},
+ {<<"yamerl">>,{pkg,<<"yamerl">>,<<"0.7.0">>},0}]}.
 [
 {pkg_hash,[
  {<<"cowlib">>, <<"BBD58EF537904E4F7C1DD62E6AA8BC831C8183CE4EFA9BD1150164FE15BE4CAA">>},
  {<<"goldrush">>, <<"F06E5D5F1277DA5C413E84D5A2924174182FB108DABB39D5EC548B27424CD106">>},
  {<<"jsx">>, <<"D2F6E5F069C00266CAD52FB15D87C428579EA4D7D73A33669E12679E203329DD">>},
  {<<"lager">>, <<"897EFC7679BB82383448646C96768CDC4E747464DD18B999C7AACA485686B0DA">>},
  {<<"ranch">>, <<"F04166F456790FEE2AC1AA05A02745CC75783C2BFB26D39FAF6AEFC9A3D3A58A">>},
- {<<"redbug">>, <<"9153EE50E42C39CE3F6EFA65EE746F4A52896DA66862CFB59E7C0F838B7B8414">>}]}
+ {<<"redbug">>, <<"9153EE50E42C39CE3F6EFA65EE746F4A52896DA66862CFB59E7C0F838B7B8414">>},
+ {<<"yamerl">>, <<"E51DBA652DCE74C20A88294130B48051EBBBB0BE7D76F22DE064F0F3CCF0AAF5">>}]}
 ].

src/erlang_ls.app.src

@@ -11,6 +11,7 @@
    , jsx
    , cowlib
    , lager
+   , yamerl
    ]},
   {env,[]},
   {modules, []},

src/erlang_ls_server.erl

@@ -41,6 +41,11 @@
 %%==============================================================================
 -type state() :: #state{}.
 
+%%==============================================================================
+%% Macros
+%%==============================================================================
+-define(DEFAULT_CONFIG_PATH, "erlang_ls.config").
+
 %%==============================================================================
 %% ranch_protocol callbacks
 %%==============================================================================
@@ -127,10 +132,12 @@ handle_method(<<"initialize">>, Params) ->
   #{ <<"rootUri">> := RootUri
    , <<"initializationOptions">> := InitOptions
    } = Params,
-  Config = erlang_config(InitOptions, RootUri),
-  OtpPath = proplists:get_value(otp_path, Config, code:root_dir()),
-  ok = erlang_ls_buffer_server:set_otp_path(OtpPath),
   ok = erlang_ls_buffer_server:set_root_uri(RootUri),
+  Config = consult_config(filename:join([ erlang_ls_uri:path(RootUri)
+                                        , config_path(InitOptions)
+                                        ])),
+  OtpPath = maps:get(<<"otp_path">>, Config, code:root_dir()),
+  ok = erlang_ls_buffer_server:set_otp_path(OtpPath),
   Result = #{ capabilities =>
                 #{ hoverProvider => false
                  , completionProvider =>
@@ -217,13 +224,21 @@ send_notification(Socket, Method, Params) ->
   lager:debug("[SERVER] Sending notification [notification=~p]", [Notification]),
   gen_tcp:send(Socket, Notification).
 
--spec erlang_config(map(), binary()) -> [term()].
-erlang_config(#{<<"erlang">> := #{<<"config">> := Filename}}, RootUri) ->
-  RootPath = erlang_ls_uri:path(RootUri),
-  Path = filename:join([RootPath, Filename]),
-  lager:info("Reading config file from ~p", [Path]),
-  %% TODO: check the file exits
-  {ok, Terms} = file:consult(Path),
-  Terms;
-erlang_config(_, _) ->
-  [].
+-spec config_path(map()) -> erlang_ls_uri:path().
+config_path(#{<<"erlang">> := #{<<"config_path">> := ConfigPath}}) ->
+  ConfigPath;
+config_path(_) ->
+  ?DEFAULT_CONFIG_PATH.
+
+-spec consult_config(erlang_ls_uri:path()) -> [any()].
+consult_config(Path) ->
+  lager:info("Reading config file. path=~p", [Path]),
+  Options = [{map_node_format, map}],
+  try yamerl:decode_file(Path, Options) of
+    [Config] -> Config
+  catch
+    Class:Error ->
+      lager:warning( "Error reading config file. path=~p class=~p error=~p"
+                   , [Path, Class, Error]),
+      #{}
+  end.

test/prop_statem.erl

@@ -185,6 +185,7 @@ setup() ->
   meck:expect(erlang_ls_compiler_diagnostics, diagnostics, 1, []),
   meck:expect(erlang_ls_dialyzer_diagnostics, diagnostics, 1, []),
   application:ensure_all_started(erlang_ls),
+  file:write_file("/tmp/erlang_ls.config", <<"">>),
   lager:set_loglevel(lager_console_backend, warning),
   ok.