feat: find references, reverts "fix: revert 0.7 (#142)" (#150)

This reverts commit 5a1713c.

Author: mhanberg

lib/next_ls.ex

@@ -19,6 +19,7 @@ defmodule NextLS do
   alias GenLSP.Requests.TextDocumentDefinition
   alias GenLSP.Requests.TextDocumentDocumentSymbol
   alias GenLSP.Requests.TextDocumentFormatting
+  alias GenLSP.Requests.TextDocumentReferences
   alias GenLSP.Requests.WorkspaceSymbol
   alias GenLSP.Structures.DidChangeWatchedFilesParams
   alias GenLSP.Structures.DidChangeWorkspaceFoldersParams
@@ -108,6 +109,7 @@ defmodule NextLS do
          document_formatting_provider: true,
          workspace_symbol_provider: true,
          document_symbol_provider: true,
+         references_provider: true,
          definition_provider: true,
          workspace: %{
            workspace_folders: %GenLSP.Structures.WorkspaceFoldersServerCapabilities{
@@ -171,6 +173,64 @@ defmodule NextLS do
     {:reply, symbols, lsp}
   end
 
+  # TODO handle `context: %{includeDeclaration: true}` to include the current symbol definition among
+  # the results.
+  def handle_request(%TextDocumentReferences{params: %{position: position, text_document: %{uri: uri}}}, lsp) do
+    file = URI.parse(uri).path
+    line = position.line + 1
+    col = position.character + 1
+
+    locations =
+      dispatch(lsp.assigns.registry, :databases, fn databases ->
+        Enum.flat_map(databases, fn {database, _} ->
+          references =
+            case symbol_info(file, line, col, database) do
+              {:function, module, function} ->
+                DB.query(
+                  database,
+                  ~Q"""
+                  SELECT file, start_line, end_line, start_column, end_column
+                  FROM "references" as refs
+                  WHERE refs.identifier = ?
+                    AND refs.type = ?
+                    AND refs.module = ?
+                    AND NOT like('/home/runner/work/elixir/%', refs.file)
+                  """,
+                  [function, "function", module]
+                )
+
+              {:module, module} ->
+                DB.query(
+                  database,
+                  ~Q"""
+                  SELECT file, start_line, end_line, start_column, end_column
+                  FROM "references" as refs
+                  WHERE refs.module = ?
+                    AND refs.type = ?
+                    AND NOT like('/home/runner/work/elixir/%', refs.file)
+                  """,
+                  [module, "alias"]
+                )
+
+              :unknown ->
+                []
+            end
+
+          for [file, start_line, end_line, start_column, end_column] <- references do
+            %Location{
+              uri: "file://#{file}",
+              range: %Range{
+                start: %Position{line: clamp(start_line - 1), character: clamp(start_column - 1)},
+                end: %Position{line: clamp(end_line - 1), character: clamp(end_column - 1)}
+              }
+            }
+          end
+        end)
+      end)
+
+    {:reply, locations, lsp}
+  end
+
   def handle_request(%WorkspaceSymbol{params: %{query: query}}, lsp) do
     filter = fn sym ->
       if query == "" do
@@ -603,4 +663,57 @@ defmodule NextLS do
       {^ref, result} -> result
     end
   end
+
+  defp symbol_info(file, line, col, database) do
+    definition_query =
+      ~Q"""
+      SELECT module, type, name
+      FROM "symbols" sym
+      WHERE sym.file = ?
+        AND sym.line = ?
+      ORDER BY sym.id ASC
+      LIMIT 1
+      """
+
+    reference_query = ~Q"""
+    SELECT identifier, type, module
+    FROM "references" refs
+    WHERE refs.file = ?
+      AND refs.start_line <= ? AND refs.end_line >= ?
+      AND refs.start_column <= ? AND refs.end_column >= ?
+    ORDER BY refs.id ASC
+    LIMIT 1
+    """
+
+    case DB.query(database, definition_query, [file, line]) do
+      [[module, "defmodule", _]] ->
+        {:module, module}
+
+      [[module, "defstruct", _]] ->
+        {:module, module}
+
+      [[module, "def", function]] ->
+        {:function, module, function}
+
+      [[module, "defp", function]] ->
+        {:function, module, function}
+
+      [[module, "defmacro", function]] ->
+        {:function, module, function}
+
+      _unknown_definition ->
+        case DB.query(database, reference_query, [file, line, line, col, col]) do
+          [[function, "function", module]] ->
+            {:function, module, function}
+
+          [[_alias, "alias", module]] ->
+            {:module, module}
+
+          _unknown_reference ->
+            :unknown
+        end
+    end
+  end
+
+  defp clamp(line), do: max(line, 0)
 end

test/next_ls_test.exs

@@ -888,6 +888,104 @@ defmodule NextLSTest do
     end
   end
 
+  describe "find references" do
+    @describetag root_paths: ["my_proj"]
+    setup %{tmp_dir: tmp_dir} do
+      File.mkdir_p!(Path.join(tmp_dir, "my_proj/lib"))
+      File.write!(Path.join(tmp_dir, "my_proj/mix.exs"), mix_exs())
+      [cwd: tmp_dir]
+    end
+
+    setup %{cwd: cwd} do
+      peace = Path.join(cwd, "my_proj/lib/peace.ex")
+
+      File.write!(peace, """
+      defmodule MyApp.Peace do
+        def and_love() do
+          "✌️"
+        end
+      end
+      """)
+
+      bar = Path.join(cwd, "my_proj/lib/bar.ex")
+
+      File.write!(bar, """
+      defmodule Bar do
+        alias MyApp.Peace
+        def run() do
+          Peace.and_love()
+        end
+      end
+      """)
+
+      [bar: bar, peace: peace]
+    end
+
+    setup :with_lsp
+
+    test "list function references", %{client: client, bar: bar, peace: peace} do
+      assert :ok == notify(client, %{method: "initialized", jsonrpc: "2.0", params: %{}})
+      assert_request(client, "client/registerCapability", fn _params -> nil end)
+      assert_notification "window/logMessage", %{"message" => "[NextLS] Runtime for folder my_proj is ready..."}
+      assert_notification "window/logMessage", %{"message" => "[NextLS] Compiled!"}
+
+      request(client, %{
+        method: "textDocument/references",
+        id: 4,
+        jsonrpc: "2.0",
+        params: %{
+          position: %{line: 1, character: 6},
+          textDocument: %{uri: uri(peace)},
+          context: %{includeDeclaration: true}
+        }
+      })
+
+      uri = uri(bar)
+
+      assert_result 4,
+                    [
+                      %{
+                        "uri" => ^uri,
+                        "range" => %{
+                          "start" => %{"line" => 3, "character" => 10},
+                          "end" => %{"line" => 3, "character" => 18}
+                        }
+                      }
+                    ]
+    end
+
+    test "list module references", %{client: client, bar: bar, peace: peace} do
+      assert :ok == notify(client, %{method: "initialized", jsonrpc: "2.0", params: %{}})
+      assert_request(client, "client/registerCapability", fn _params -> nil end)
+      assert_notification "window/logMessage", %{"message" => "[NextLS] Runtime for folder my_proj is ready..."}
+      assert_notification "window/logMessage", %{"message" => "[NextLS] Compiled!"}
+
+      request(client, %{
+        method: "textDocument/references",
+        id: 4,
+        jsonrpc: "2.0",
+        params: %{
+          position: %{line: 0, character: 10},
+          textDocument: %{uri: uri(peace)},
+          context: %{includeDeclaration: true}
+        }
+      })
+
+      uri = uri(bar)
+
+      assert_result 4,
+                    [
+                      %{
+                        "uri" => ^uri,
+                        "range" => %{
+                          "start" => %{"line" => 3, "character" => 4},
+                          "end" => %{"line" => 3, "character" => 9}
+                        }
+                      }
+                    ]
+    end
+  end
+
   describe "workspaces" do
     setup %{tmp_dir: tmp_dir} do
       [cwd: tmp_dir]