elipl/test/til/parse_atom_test.exs

defmodule Til.ParseAtomTest do
  use ExUnit.Case, async: true

  alias Til.Parser
  import Til.TestHelpers

  describe "Atom parsing" do
    test "parses a simple atom" do
      source = ":hello"
      {:ok, _nodes_map} = Parser.parse(source)
      {atom_node, _map} = parse_and_get_first_node(source)

      assert atom_node.ast_node_type == :literal_atom
      assert atom_node.value == :hello
      assert atom_node.raw_string == ":hello"
      assert atom_node.location == [0, 1, 1, 6, 1, 7]
    end

    test "parses an atom with numbers and underscores" do
      source = ":foo_123_bar"
      {:ok, _nodes_map} = Parser.parse(source)
      {atom_node, _map} = parse_and_get_first_node(source)

      assert atom_node.ast_node_type == :literal_atom
      assert atom_node.value == :foo_123_bar
      assert atom_node.raw_string == ":foo_123_bar"
    end

    test "parses an atom within an s-expression" do
      source = "(:an_atom)"
      {:ok, nodes_map} = Parser.parse(source)
      s_expr_node = get_first_child_node(nodes_map)
      atom_node_id = hd(s_expr_node.children)
      atom_node = get_node_by_id(nodes_map, atom_node_id)

      assert atom_node.ast_node_type == :literal_atom
      assert atom_node.value == :an_atom
      assert atom_node.raw_string == ":an_atom"
      # Location of :an_atom within ()
      assert atom_node.location == [1, 1, 2, 9, 1, 10]
    end

    test "parses multiple atoms in an s-expression" do
      source = "(:first :second)"
      {:ok, nodes_map} = Parser.parse(source)
      s_expr_node = get_first_child_node(nodes_map)

      first_atom_node = get_node_by_id(nodes_map, Enum.at(s_expr_node.children, 0))
      assert first_atom_node.ast_node_type == :literal_atom
      assert first_atom_node.value == :first
      assert first_atom_node.raw_string == ":first"

      second_atom_node = get_node_by_id(nodes_map, Enum.at(s_expr_node.children, 1))
      assert second_atom_node.ast_node_type == :literal_atom
      assert second_atom_node.value == :second
      assert second_atom_node.raw_string == ":second"
    end

    test "parses an atom followed immediately by an opening parenthesis (delimiter)" do
      source = ":atom_name(foo)"
      {:ok, nodes_map} = Parser.parse(source)

      # First child of the file node should be the atom
      atom_node = get_nth_child_node(nodes_map, 0)
      assert atom_node.ast_node_type == :literal_atom
      assert atom_node.value == :atom_name
      assert atom_node.raw_string == ":atom_name"
      assert atom_node.location == [0, 1, 1, 10, 1, 11]

      # Second child should be the s-expression
      s_expr_node = get_nth_child_node(nodes_map, 1)
      assert s_expr_node.ast_node_type == :s_expression
      assert s_expr_node.raw_string == "(foo)"
    end

    test "parses an atom at the end of input" do
      source = "  :last_atom  "
      {:ok, nodes_map} = Parser.parse(source)
      # Use trimmed for helper
      {atom_node, _map} = parse_and_get_first_node(String.trim(source))

      assert atom_node.ast_node_type == :literal_atom
      assert atom_node.value == :last_atom
      assert atom_node.raw_string == ":last_atom"
      # Location needs to be checked against the original source with whitespace
      file_node = get_file_node_from_map(nodes_map)
      actual_atom_node_id = hd(file_node.children)
      actual_atom_node = get_node_by_id(nodes_map, actual_atom_node_id)
      # "  :last_atom  "
      assert actual_atom_node.location == [2, 1, 3, 12, 1, 13]
    end

    test "parses atom within a list expression" do
      source = "[:my_list_atom]"
      {:ok, nodes_map} = Parser.parse(source)
      list_expr_node = get_first_child_node(nodes_map)
      atom_node_id = hd(list_expr_node.children)
      atom_node = get_node_by_id(nodes_map, atom_node_id)

      assert atom_node.ast_node_type == :literal_atom
      assert atom_node.value == :my_list_atom
      assert atom_node.raw_string == ":my_list_atom"
    end

    test "parses atom within a tuple expression" do
      source = "{:my_tuple_atom}"
      {:ok, nodes_map} = Parser.parse(source)
      tuple_expr_node = get_first_child_node(nodes_map)
      atom_node_id = hd(tuple_expr_node.children)
      atom_node = get_node_by_id(nodes_map, atom_node_id)

      assert atom_node.ast_node_type == :literal_atom
      assert atom_node.value == :my_tuple_atom
      assert atom_node.raw_string == ":my_tuple_atom"
    end

    test "parses atom as a key in a map expression" do
      source = "m{:key 1}"
      {:ok, nodes_map} = Parser.parse(source)
      map_expr_node = get_first_child_node(nodes_map)

      key_node_id = Enum.at(map_expr_node.children, 0)
      key_node = get_node_by_id(nodes_map, key_node_id)

      assert key_node.ast_node_type == :literal_atom
      assert key_node.value == :key
      assert key_node.raw_string == ":key"

      value_node_id = Enum.at(map_expr_node.children, 1)
      value_node = get_node_by_id(nodes_map, value_node_id)
      assert value_node.ast_node_type == :literal_integer
      assert value_node.value == 1
    end

    test "parses atom as a value in a map expression" do
      source = "m{'string_key' :atom_value}"
      {:ok, nodes_map} = Parser.parse(source)
      map_expr_node = get_first_child_node(nodes_map)

      # string_key_node is child 0
      value_node_id = Enum.at(map_expr_node.children, 1)
      value_node = get_node_by_id(nodes_map, value_node_id)

      assert value_node.ast_node_type == :literal_atom
      assert value_node.value == :atom_value
      assert value_node.raw_string == ":atom_value"
    end
  end
end