feat: add signature help

Author: lucacervello

lib/next_ls.ex

@@ -713,7 +713,7 @@ defmodule NextLS do
     result =
       dispatch(lsp.assigns.registry, :databases, fn entries ->
         for {pid, _} <- entries do
-          SignatureHelp.fetch(URI.parse(uri).path, {position.line + 1, position.character + 1}, pid, lsp.assigns.logger)
+          SignatureHelp.fetch(URI.parse(uri).path, {position.line + 1, position.character + 1}, pid)
         end
       end)
 

lib/next_ls/helpers/ast_helpers.ex

@@ -152,64 +152,4 @@ defmodule NextLS.ASTHelpers do
       end
     end)
   end
-
-  defmodule Functions do
-    @moduledoc false
-
-    alias Sourceror.Zipper, as: Z
-
-    def get_function_params(code, identifier, line, _col) do
-      ast =
-        NextLS.Parser.parse!(code, columns: true)
-
-      identifier = String.to_atom(identifier)
-
-      {_ast, args} =
-        Macro.prewalk(ast, nil, fn
-          {^identifier, [line: ^line, column: _], args} = ast, _acc -> {ast, args}
-          other, acc -> {other, acc}
-        end)
-
-      if args do
-        args
-      else
-        []
-      end
-    end
-
-    def get_function_name_from_params(code, line, col) do
-      pos = [line: line + 1, column: col + 1]
-
-      ast =
-        case Spitfire.parse(code) do
-          {:ok, ast} ->
-            ast
-
-          {:error, ast, _errors} ->
-            ast
-        end
-
-      {_ast, result} =
-        ast
-        |> Z.zip()
-        |> Z.traverse(nil, fn tree, acc ->
-          node = Z.node(tree)
-          range = Sourceror.get_range(node)
-
-          if not is_nil(range) and
-               match?({:., _, [{:__aliases__, _, _aliases}, _identifier]}, node) do
-            if Sourceror.compare_positions(range.end, pos) == :lt do
-              {:., _, [{:__aliases__, _, aliases}, identifier]} = node
-              {tree, {aliases, identifier}}
-            else
-              {tree, acc}
-            end
-          else
-            {tree, acc}
-          end
-        end)
-
-      result
-    end
-  end
 end

lib/next_ls/logger.ex

@@ -24,7 +24,7 @@ defmodule NextLS.Logger do
 
   def handle_cast({:log, type, msg}, state) do
     apply(GenLSP, type, [state.lsp, String.trim("[Next LS] #{msg}")])
-    
+
     case type do
       :log -> Logger.debug(msg)
       :warning -> Logger.warning(msg)

lib/next_ls/signature_help.ex

@@ -1,76 +1,50 @@
 defmodule NextLS.SignatureHelp do
   @moduledoc false
 
-  import NextLS.DB.Query
-
-  alias GenLSP.Enumerations.MarkupKind
-  alias GenLSP.Structures.MarkupContent
   alias GenLSP.Structures.ParameterInformation
   alias GenLSP.Structures.SignatureHelp
   alias GenLSP.Structures.SignatureInformation
-  alias NextLS.ASTHelpers
-  alias NextLS.DB
-
-  def fetch(file, {line, col}, db, _logger) do
-    code = File.read!(file)
-
-    {mod, func} =
-      ASTHelpers.Functions.get_function_name_from_params(code, line, col)
-
-    query =
-      ~Q"""
-      SELECT
-          *
-      FROM
-          symbols
-      WHERE
-          symbols.module = ?
-          AND symbols.name = ?;
-      """
-
-    args = [Enum.map_join(mod, ".", &Atom.to_string/1), Atom.to_string(func)]
-
-    symbol = DB.query(db, query, args)
-
-    result =
-      case symbol do
-        nil ->
+  alias NextLS.Definition
+
+  def fetch(file, {line, col}, db) do
+    case Definition.fetch(file, {line, col}, db) do
+      nil ->
+        nil
+
+      [] ->
+        nil
+
+      [[_, _mod, _file, type, label, params, _line, _col | _] | _] = _definition ->
+        if type in ["def", "defp"] do
+          term_params =
+            :erlang.binary_to_term(params)
+
+          code_params =
+            term_params
+            |> Macro.to_string()
+            |> String.replace_prefix("[", "(")
+            |> String.replace_suffix("]", ")")
+
+          params_info =
+            term_params
+            |> Enum.map(&Macro.to_string/1)
+            |> Enum.map(fn name ->
+              %ParameterInformation{
+                label: name
+              }
+            end)
+
+          %SignatureHelp{
+            signatures: [
+              %SignatureInformation{
+                label: "#{label}#{code_params}",
+                parameters: params_info
+              }
+            ]
+          }
+        else
           nil
-
-        [] ->
-          nil
-
-        [[_, _mod, file, type, label, params, line, col | _] | _] = _definition ->
-          if type in ["def", "defp"] do
-            code_params = params |> :erlang.binary_to_term() |> Macro.to_string() |> dbg()
-
-            signature_params =
-              params
-              |> :erlang.binary_to_term()
-              |> Enum.map(fn {name, _, _} ->
-                %ParameterInformation{
-                  label: Atom.to_string(name)
-                }
-              end)
-              |> dbg()
-
-            %SignatureHelp{
-              signatures: [
-                %SignatureInformation{
-                  label: "#{label}.#{code_params}",
-                  documentation: "need help",
-                  parameters: signature_params
-                  # active_parameter: 0
-                }
-              ]
-              # active_signature: 1,
-              # active_parameter: 0
-            }
-          else
-            nil
-          end
-      end
-
-    result
+        end
+    end
   end
 end

test/next_ls/helpers/ast_helpers_test.exs

@@ -74,53 +74,4 @@ defmodule NextLS.ASTHelpersTest do
       assert {{5, 5}, {5, 8}} == Aliases.extract_alias_range(code, {start, stop}, :Four)
     end
   end
-
-  describe "extract function params" do
-    test "simple function params" do
-      code = """
-      @doc "foo doc"
-      def foo(bar, baz) do
-        :ok
-      end
-      """
-
-      assert [{:bar, [line: 2, column: 9], nil}, {:baz, [line: 2, column: 14], nil}] ==
-               ASTHelpers.Functions.get_function_params(code, "foo", 2, 5)
-    end
-  end
-
-  describe "extract function name from params" do
-    test "alias function" do
-      code = """
-      defmodule MyModule do
-        List.starts_with?(
-      end
-      """
-
-      assert {[:List], :starts_with?} ==
-               ASTHelpers.Functions.get_function_name_from_params(code, 2, 21)
-    end
-
-    test "nested alias function" do
-      code = """
-      defmodule MyModule do
-        List.starts_with?(String.trim()
-      end
-      """
-
-      assert {[:String], :trim} ==
-               ASTHelpers.Functions.get_function_name_from_params(code, 2, 37)
-    end
-
-    test "simple function" do
-      code = """
-      defmodule MyModule do
-        put_in(
-      end
-      """
-
-      assert :put_in ==
-               ASTHelpers.Functions.get_function_name_from_params(code, 2, 21)
-    end
-  end
 end

test/next_ls/signature_help_test.exs

@@ -29,7 +29,7 @@ defmodule NextLS.SignatureHelpTest do
 
       File.write!(imported, """
       defmodule Imported do
-        def boom(boom1, _boom2) do
+        def boom([] = boom1, _boom2) do
           boom1
         end
       end
@@ -40,12 +40,22 @@ defmodule NextLS.SignatureHelpTest do
       File.write!(bar, """
       defmodule Bar do
         def run() do
-          Remote.bang!()
+          Remote.bang!("!")
         end
       end
       """)
 
-      [bar: bar, imported: imported, remote: remote]
+      baz = Path.join(cwd, "my_proj/lib/baz.ex")
+
+      File.write!(baz, """
+      defmodule Baz do
+        def run() do
+          Imported.boom([1, 2], 1)
+        end
+      end
+      """)
+
+      [bar: bar, imported: imported, remote: remote, baz: baz]
     end
 
     setup :with_lsp
@@ -63,56 +73,49 @@ defmodule NextLS.SignatureHelpTest do
         id: 4,
         jsonrpc: "2.0",
         params: %{
-          position: %{line: 3, character: 16},
+          position: %{line: 2, character: 13},
           textDocument: %{uri: uri}
         }
       })
 
       assert_result 4, %{
-        "activeParameter" => 0,
-        "activeSignature" => 0,
         "signatures" => [
           %{
-            "activeParameter" => 0,
             "parameters" => [
               %{"label" => "bang"}
             ],
-            "documentation" => "need help",
-            "label" => "bang!"
+            "label" => "bang!(bang)"
           }
         ]
       }
     end
 
-    test "get signature help 2", %{client: client, bar: bar} = context do
+    test "get signature help 2", %{client: client, baz: baz} = context do
       assert :ok == notify(client, %{method: "initialized", jsonrpc: "2.0", params: %{}})
 
       assert_is_ready(context, "my_proj")
       assert_notification "$/progress", %{"value" => %{"kind" => "end", "message" => "Finished indexing!"}}
 
-      uri = uri(bar)
+      uri = uri(baz)
 
       request(client, %{
         method: "textDocument/signatureHelp",
         id: 4,
         jsonrpc: "2.0",
         params: %{
-          position: %{line: 8, character: 10},
+          position: %{line: 2, character: 13},
           textDocument: %{uri: uri}
         }
       })
 
       assert_result 4, %{
-        "activeParameter" => 0,
-        "activeSignature" => 0,
         "signatures" => [
           %{
-            "activeParameter" => 0,
             "parameters" => [
-              %{"label" => "bang"}
+              %{"label" => "[] = boom1"},
+              %{"label" => "_boom2"}
             ],
-            "documentation" => "need help",
-            "label" => "bang!"
+            "label" => "boom([] = boom1, _boom2)"
           }
         ]
       }