lib/byebug/commands/condition.rb



# frozen_string_literal: true

require_relative "../command"
require_relative "../helpers/parse"

module Byebug
  #
  # Implements conditions on breakpoints.
  #
  # Adds the ability to stop on breakpoints only under certain conditions.
  #
  class ConditionCommand < Command
    include Helpers::ParseHelper

    self.allow_in_post_mortem = true

    def self.regexp
      /^\s* cond(?:ition)? (?:\s+(\d+)(?:\s+(.*))?)? \s*$/x
    end

    def self.description
      <<-DESCRIPTION
        cond[ition] <n>[ expr]

        #{short_description}

        Specify breakpoint number <n> to break only if <expr> is true. <n> is
        an integer and <expr> is an expression to be evaluated whenever
        breakpoint <n> is reached. If no expression is specified, the condition
        is removed.
      DESCRIPTION
    end

    def self.short_description
      "Sets conditions on breakpoints"
    end

    def execute
      return puts(help) unless @match[1]

      breakpoints = Byebug.breakpoints.sort_by(&:id)
      return errmsg(pr("condition.errors.no_breakpoints")) if breakpoints.empty?

      pos, err = get_int(@match[1], "Condition", 1)
      return errmsg(err) if err

      breakpoint = breakpoints.find { |b| b.id == pos }
      return errmsg(pr("break.errors.no_breakpoint")) unless breakpoint

      return errmsg(pr("break.errors.not_changed", expr: @match[2])) unless syntax_valid?(@match[2])

      breakpoint.expr = @match[2]
    end
  end
end