method

sole

v8.1.1 - Show latest stable - Class: Enumerable

sole()

public

Returns the sole item in the enumerable. If there are no items, or more than one item, raises Enumerable::SoleItemExpectedError.

["x"].sole          # => "x"
Set.new.sole        # => Enumerable::SoleItemExpectedError: no item found
{ a: 1, b: 2 }.sole # => Enumerable::SoleItemExpectedError: multiple items found

# File activesupport/lib/active_support/core_ext/enumerable.rb, line 211
  def sole
    result = nil
    found = false

    each do |*element|
      if found
        raise SoleItemExpectedError, "multiple items found"
      end

      result = element.size == 1 ? element[0] : element
      found = true
    end

    if found
      result
    else
      raise SoleItemExpectedError, "no item found"
    end
  end

sole

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