Working prototype for indenting entire function on .

Co-authored-by: Andreas Hasselberg <andreas.hasselberg@gmail.com>

Delete iostr.erl

Fix linter complaints

Fix proper error

Fix typespec

Maybe make Dialyzer happy?

Temp fixes to get dialyzer to run

Add spec

Better fix for dialyzer errors

Add config to enable on type formatting, defaulting to false

Skip formatting if . is on a commented out line

Author: onno-vos-dev

apps/els_core/include/els_core.hrl

@@ -548,8 +548,8 @@
                                }.
 
 -type document_ontypeformatting_options() :: false |
-       #{ first_trigger_character := string()
-        , more_trigger_character  => string()
+       #{ firstTriggerCharacter := binary()
+        , moreTriggerCharacter  => [binary()]
         }.
 
 %%------------------------------------------------------------------------------
@@ -612,7 +612,8 @@
                    | {atom(), atom()} %% record_def_field, record_field
                    | string() %% include, include_lib
                    | {atom(), arity()}
-                   | {module(), atom(), arity()}.
+                   | {module(), atom(), arity()}
+                   | pos().
 -type poi()       :: #{ kind  := poi_kind()
                       , id    := poi_id()
                       , data  := any()

apps/els_core/src/els_client.erl

@@ -452,6 +452,10 @@ request_params({initialize, {RootUri, InitOptions}}) ->
                     #{ <<"contextSupport">> => 'true' }
                   , <<"hover">> =>
                     #{ <<"contentFormat">> => ContentFormat }
+                  , <<"documentOnTypeFormattingProvider">> =>
+                      #{ firstTriggerCharacter => <<",">>
+                       , moreTriggercharacter => []
+                       }
                   },
   #{ <<"rootUri">> => RootUri
    , <<"initializationOptions">> => InitOptions

apps/els_core/src/els_config.erl

@@ -125,6 +125,7 @@ do_initialize(RootUri, Capabilities, InitOptions, {ConfigPath, Config}) ->
     = maps:get("compiler_telemetry_enabled", Config, false),
 
   IndexingEnabled = maps:get(<<"indexingEnabled">>, InitOptions, true),
+  FormatOnTypeEnabled = maps:get("format_on_type", Config, false),
 
   %% Passed by the LSP client
   ok = set(root_uri       , RootUri),
@@ -138,6 +139,7 @@ do_initialize(RootUri, Capabilities, InitOptions, {ConfigPath, Config}) ->
   ok = set(macros         , Macros),
   ok = set(plt_path       , DialyzerPltPath),
   ok = set(code_reload    , CodeReload),
+  ok = set(format_on_type , FormatOnTypeEnabled),
   ?LOG_INFO("Config=~p", [Config]),
   ok = set(runtime, maps:merge( els_config_runtime:default_config()
                               , Runtime)),

apps/els_lsp/src/els_dt_document.erl

@@ -21,15 +21,16 @@
         , lookup/1
         ]).
 
--export([ new/2
+-export([ get_element_at_pos/3
+        , new/2
         , pois/1
         , pois/2
-        , get_element_at_pos/3
         , uri/1
         , functions_at_pos/3
         , applications_at_pos/3
         , wrapping_functions/2
         , wrapping_functions/3
+        , text/1
         ]).
 
 %%==============================================================================
@@ -63,6 +64,7 @@
                  , md5  => binary()
                  , pois => [poi()]
                  }.
+
 -export_type([ id/0
              , item/0
              , kind/0
@@ -155,6 +157,10 @@ new(Uri, Text, Id, Kind) ->
 pois(#{ pois := POIs }) ->
   POIs.
 
+-spec text(item()) -> binary().
+text(#{text := Text}) ->
+  Text.
+
 %% @doc Returns the list of POIs of the given types for the current
 %%      document
 -spec pois(item(), [poi_kind()]) -> [poi()].

apps/els_lsp/src/els_formatting_provider.erl

@@ -49,13 +49,17 @@ is_enabled_document() -> true.
 
 -spec is_enabled_range() -> boolean().
 is_enabled_range() ->
-  false.
+  true.
 
 %% NOTE: because erlang_ls does not send incremental document changes
 %%       via `textDocument/didChange`, this kind of formatting does not
 %%       make sense.
 -spec is_enabled_on_type() -> document_ontypeformatting_options().
-is_enabled_on_type() -> false.
+is_enabled_on_type() ->
+  case els_config:get(format_on_type) of
+    true -> #{firstTriggerCharacter => <<".">>, moreTriggerCharacter => []};
+    false -> false
+  end.
 
 -spec handle_request(any(), state()) -> {any(), state()}.
 handle_request({document_formatting, Params}, State) ->
@@ -157,5 +161,71 @@ rangeformat_document(_Uri, _Document, _Range, _Options) ->
 -spec ontypeformat_document(binary(), map()
                            , number(), number(), string(), formatting_options())
                            -> {ok, [text_edit()]}.
-ontypeformat_document(_Uri, _Document, _Line, _Col, _Char, _Options) ->
-    {ok, []}.
+ontypeformat_document(_Uri, Document, Line, Col, <<".">>, _Options) ->
+  case find_matching_range(Document, Line) of
+    [] ->
+      {ok, []};
+    [MatchingRange] ->
+      {StartLine, _} = Id = els_poi:id(MatchingRange),
+      Text = els_dt_document:text(Document),
+      RangeText = els_text:range(Text, Id, {Line, Col}),
+      % Skip formatting if the . is on a commented line.
+      case string:trim(els_text:line(Text, Line - 1), both) of
+        <<"%", _/binary>> ->
+          {ok, []};
+        _ ->
+          ParseF =
+            fun(Dir) ->
+               TmpFile = tmp_file(Dir),
+               ok = file:write_file(TmpFile, RangeText),
+               Opts = #{break_indent => 2, output_dir => current},
+               RebarState = #{},
+               T = rebar3_formatter:new(default_formatter, Opts, RebarState),
+               rebar3_formatter:format_file(TmpFile, T),
+               {ok, Bin} = file:read_file(TmpFile),
+               Bin
+            end,
+          %% rebar3_formatter adds a newline, since we terminate on .
+          %% We want to leave the cursor at the current char rather
+          %% than jumping to a newline
+          NewText =
+            string:trim(
+              tempdir:mktmp(ParseF), trailing, "\n"),
+          {ok,
+           [#{range =>
+                #{start => #{line => StartLine - 1, character => 0},
+                  'end' => #{line => Line - 1, character => Col}},
+              newText => NewText}]}
+      end
+  end;
+ontypeformat_document(_Uri, _Document, _Line, _Col, Char, _Options) ->
+  ?LOG_INFO("Got unhandled character in ontypeformat_document. No formatter "
+            "configured for char: ~p",
+            [Char]),
+  {ok, []}.
+
+-spec find_foldable_ranges(els_dt_document:item()) -> [poi()].
+find_foldable_ranges(Document) ->
+  Pois = els_dt_document:pois(Document),
+  lists:filter(fun (#{kind := folding_range}) ->
+                     true;
+                   (_) ->
+                     false
+               end,
+               Pois).
+
+-spec find_matching_range(els_dt_document:item(), number()) -> [poi()].
+find_matching_range(Document, Line) ->
+  lists:filter(fun(#{range := #{from := {FromLine, _}, to := {ToLine, _}}}) ->
+                  Line >= FromLine andalso Line =< ToLine
+               end,
+               find_foldable_ranges(Document)).
+
+-spec tmp_file(string()) -> any().
+tmp_file(Dir) ->
+  Unique = erlang:unique_integer([positive]),
+  {A, B, C} = os:timestamp(),
+  N = node(),
+  filename:join(Dir,
+                lists:flatten(
+                  io_lib:format("~p-~p.~p.~p.~p", [N, A, B, C, Unique]))).

apps/els_lsp/src/els_general_provider.erl

@@ -157,6 +157,8 @@ server_capabilities() ->
             els_formatting_provider:is_enabled_document()
         , documentRangeFormattingProvider =>
             els_formatting_provider:is_enabled_range()
+        , documentOnTypeFormattingProvider =>
+            els_formatting_provider:is_enabled_on_type()
         , foldingRangeProvider =>
             els_folding_range_provider:is_enabled()
         , implementationProvider =>

apps/els_lsp/src/els_poi.erl

@@ -10,6 +10,7 @@
 
 -export([ match_pos/2
         , sort/1
+        , id/1
         ]).
 
 %%==============================================================================
@@ -42,6 +43,10 @@ match_pos(POIs, Pos) ->
                       , to   := To
                       }} = POI <- POIs, (From =< Pos) andalso (Pos =< To)].
 
+-spec id(poi()) -> poi_id().
+id(#{id := Id}) ->
+  Id.
+
 %% @doc Sorts pois based on their range
 %%
 %% Order is defined using els_range:compare/2.