Module: Test::Unit::Assertions

Included in:
TestCase
Defined in:
lib/test/unit/assertions.rb

Overview

Test::Unit::Assertions contains the standard Test::Unit assertions. Assertions is included in Test::Unit::TestCase.

To include it in your own code and use its functionality, you simply need to rescue Test::Unit::AssertionFailedError. Additionally you may override add_assertion to get notified whenever an assertion is made.

Notes:

  • The message to each assertion, if given, will be propagated with the failure.

  • It is easy to add your own assertions based on assert_block().

Example Custom Assertion

def deny(boolean, message = nil)
  message = build_message message, '<?> is not false or nil.', boolean
  assert_block message do
    not boolean
  end
end

Defined Under Namespace

Classes: AssertExceptionHelper, AssertionMessage

Constant Summary collapse

UncaughtThrow = 
{
  NameError => /^uncaught throw \`(.+)\'$/,
  ArgumentError => /^uncaught throw (.+)$/,
  ThreadError => /^uncaught throw \`(.+)\' in thread /
}

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.use_pp=(value) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 888

def self.use_pp=(value)
  AssertionMessage.use_pp = value
end

Instance Method Details

#assert(boolean, message = nil) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 63

def assert(boolean, message=nil)
  _wrap_assertion do
    assert_block("assert should not be called with a block.") { !block_given? }
    assert_block(build_message(message, "<?> is not true.", boolean)) { boolean }
  end
end

#assert_alias_method(object, alias_name, original_name, message = nil) ⇒ Object

Passes if object#alias_name is an alias method of object#original_name.

Example:

assert_alias_method([], :length, :size)  # -> pass
assert_alias_method([], :size, :length)  # -> pass
assert_alias_method([], :each, :size)    # -> fail



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# File 'lib/test/unit/assertions.rb', line 809

def assert_alias_method(object, alias_name, original_name, message=nil)
  _wrap_assertion do
    find_method_failure_message = Proc.new do |method_name|
      build_message(message,
                    "<?>.? doesn't exist\n" +
                    "(Class: <?>)",
                    object,
                    AssertionMessage.literal(method_name),
                    object.class)
    end

    alias_method = original_method = nil
    assert_block(find_method_failure_message.call(alias_name)) do
      begin
        alias_method = object.method(alias_name)
        true
      rescue NameError
        false
      end
    end
    assert_block(find_method_failure_message.call(original_name)) do
      begin
        original_method = object.method(original_name)
        true
      rescue NameError
        false
      end
    end

    full_message = build_message(message,
                                 "<?> is alias of\n" +
                                 "<?> expected",
                                 alias_method,
                                 original_method)
    assert_block(full_message) do
      alias_method == original_method
    end
  end
end

#assert_block(message = "assert_block failed.") ⇒ Object

:yields:



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# File 'lib/test/unit/assertions.rb', line 48

def assert_block(message="assert_block failed.") # :yields: 
  _wrap_assertion do
    if (! yield)
      raise AssertionFailedError.new(message.to_s)
    end
  end
end

#assert_boolean(actual, message = nil) ⇒ Object

Passes if actual is a boolean value.

Example:

assert_boolean(true) # -> pass
assert_boolean(nil)  # -> fail



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# File 'lib/test/unit/assertions.rb', line 585

def assert_boolean(actual, message=nil)
  _wrap_assertion do
    assert_block(build_message(message,
                               "<true> or <false> expected but was\n<?>",
                               actual)) do
      [true, false].include?(actual)
    end
  end
end

#assert_compare(expected, operator, actual, message = nil) ⇒ Object

Passes if expression “expected operator actual” is true.

Example:

assert_compare(1, "<", 10)  # -> pass
assert_compare(1, ">=", 10) # -> fail



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# File 'lib/test/unit/assertions.rb', line 634

def assert_compare(expected, operator, actual, message=nil)
  _wrap_assertion do
    assert_send([["<", "<=", ">", ">="], :include?, operator.to_s])
    case operator.to_s
    when "<"
      operator_description = "less than"
    when "<="
      operator_description = "less than or equal to"
    when ">"
      operator_description = "greater than"
    when ">="
      operator_description = "greater than or equal to"
    end
    template = <<-EOT
<?> #{operator} <?> should be true
<?> expected #{operator_description}
<?>.
EOT
    full_message = build_message(message, template,
                                 expected, actual,
                                 expected, actual)
    assert_block(full_message) do
      expected.send(operator, actual)
    end
  end
end

#assert_const_defined(object, constant_name, message = nil) ⇒ Object

Passes if object.const_defined?(constant_name)

Example:

assert_const_defined(Test, :Unit)          # -> pass
assert_const_defined(Object, :Nonexistent) # -> fail



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# File 'lib/test/unit/assertions.rb', line 729

def assert_const_defined(object, constant_name, message=nil)
  _wrap_assertion do
    full_message = build_message(message,
                                 "<?>.const_defined\\?(<?>) expected.",
                                 object, constant_name)
    assert_block(full_message) do
      object.const_defined?(constant_name)
    end
  end
end

#assert_equal(expected, actual, message = nil) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 81

def assert_equal(expected, actual, message=nil)
  diff = AssertionMessage.delayed_diff(expected, actual)
  full_message = build_message(message, <<EOT, expected, actual, diff)
<?> expected but was
<?>.?
EOT
  begin
    assert_block(full_message) { expected == actual }
  rescue AssertionFailedError => failure
    failure.expected = expected
    failure.actual = actual
    failure.inspected_expected = AssertionMessage.convert(expected)
    failure.inspected_actual = AssertionMessage.convert(actual)
    failure.user_message = message
    raise
  end
end

#assert_fail_assertion(message = nil) ⇒ Object

Passes if assertion is failed in block.

Example:

assert_fail_assertion {assert_equal("A", "B")}  # -> pass
assert_fail_assertion {assert_equal("A", "A")}  # -> fail



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# File 'lib/test/unit/assertions.rb', line 667

def assert_fail_assertion(message=nil)
  _wrap_assertion do
    full_message = build_message(message,
                                 "Failed assertion was expected.")
    assert_block(full_message) do
      begin
        yield
        false
      rescue AssertionFailedError
        true
      end
    end
  end
end

#assert_false(actual, message = nil) ⇒ Object

Passes if actual is false.

Example:

assert_false(false)  # -> pass
assert_false(nil)    # -> fail



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# File 'lib/test/unit/assertions.rb', line 617

def assert_false(actual, message=nil)
  _wrap_assertion do
    assert_block(build_message(message,
                               "<false> expected but was\n<?>",
                               actual)) do
      actual == false
    end
  end
end

#assert_in_delta(expected_float, actual_float, delta, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 540

def assert_in_delta(expected_float, actual_float, delta, message="")
  _wrap_assertion do
    {expected_float => "first float", actual_float => "second float", delta => "delta"}.each do |float, name|
      assert_respond_to(float, :to_f, "The arguments must respond to to_f; the #{name} did not")
    end
    assert_operator(delta, :>=, 0.0, "The delta should not be negative")
    full_message = build_message(message, <<EOT, expected_float, actual_float, delta)
<?> and
<?> expected to be within
<?> of each other.
EOT
    assert_block(full_message) { (expected_float.to_f - actual_float.to_f).abs <= delta.to_f }
  end
end

#assert_instance_of(klass, object, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 176

def assert_instance_of(klass, object, message="")
  _wrap_assertion do
    klasses = nil
    klasses = klass if klass.is_a?(Array)
    assert_block("The first parameter to assert_instance_of should be " +
                 "a Class or an Array of Class.") do
      if klasses
        klasses.all? {|k| k.is_a?(Class)}
      else
        klass.is_a?(Class)
      end
    end
    klass_message = AssertionMessage.maybe_container(klass) do |value|
      "<#{value}>"
    end
    full_message = build_message(message, <<EOT, object, klass_message, object.class)
<?> expected to be an instance of
? but was
<?>.
EOT
    assert_block(full_message) do
      if klasses
        klasses.any? {|k| object.instance_of?(k)}
      else
        object.instance_of?(klass)
      end
    end
  end
end

#assert_kind_of(klass, object, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 231

def assert_kind_of(klass, object, message="")
  _wrap_assertion do
    klasses = nil
    klasses = klass if klass.is_a?(Array)
    assert_block("The first parameter to assert_kind_of should be " +
                 "a kind_of Module or an Array of a kind_of Module.") do
      if klasses
        klasses.all? {|k| k.kind_of?(Module)}
      else
        klass.kind_of?(Module)
      end
    end
    klass_message = AssertionMessage.maybe_container(klass) do |value|
      "<#{value}>"
    end
    full_message = build_message(message,
                                 "<?> expected to be kind_of\\?\n" +
                                 "? but was\n" +
                                 "<?>.",
                                 object,
                                 klass_message,
                                 object.class)
    assert_block(full_message) do
      if klasses
        klasses.any? {|k| object.kind_of?(k)}
      else
        object.kind_of?(klass)
      end
    end
  end
end

#assert_match(pattern, string, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 294

def assert_match(pattern, string, message="")
  _wrap_assertion do
    pattern = case(pattern)
      when String
        Regexp.new(Regexp.escape(pattern))
      else
        pattern
    end
    full_message = build_message(message, "<?> expected to be =~\n<?>.", string, pattern)
    assert_block(full_message) { string =~ pattern }
  end
end

#assert_nil(object, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 213

def assert_nil(object, message="")
  full_message = build_message(message, <<EOT, object)
<?> expected to be nil.
EOT
  assert_block(full_message) { object.nil? }
end

#assert_no_match(regexp, string, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 440

def assert_no_match(regexp, string, message="")
  _wrap_assertion do
    assert_instance_of(Regexp, regexp, "The first argument to assert_no_match should be a Regexp.")
    full_message = build_message(message, "<?> expected to not match\n<?>.", regexp, string)
    assert_block(full_message) { regexp !~ string }
  end
end

#assert_not_const_defined(object, constant_name, message = nil) ⇒ Object

Passes if !object.const_defined?(constant_name)

Example:

assert_not_const_defined(Object, :Nonexistent) # -> pass
assert_not_const_defined(Test, :Unit)          # -> fail



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# File 'lib/test/unit/assertions.rb', line 746

def assert_not_const_defined(object, constant_name, message=nil)
  _wrap_assertion do
    full_message = build_message(message,
                                 "!<?>.const_defined\\?(<?>) expected.",
                                 object, constant_name)
    assert_block(full_message) do
      !object.const_defined?(constant_name)
    end
  end
end

#assert_not_equal(expected, actual, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 416

def assert_not_equal(expected, actual, message="")
  full_message = build_message(message, "<?> expected to be != to\n<?>.", expected, actual)
  assert_block(full_message) { expected != actual }
end

#assert_not_nil(object, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 428

def assert_not_nil(object, message="")
  full_message = build_message(message, "<?> expected to not be nil.", object)
  assert_block(full_message){!object.nil?}
end

#assert_not_predicate(object, predicate, message = nil) ⇒ Object

Passes if object.predicate

Example:

assert_not_predicate([1], :empty?) # -> pass
assert_not_predicate([], :empty?)  # -> fail



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# File 'lib/test/unit/assertions.rb', line 785

def assert_not_predicate(object, predicate, message=nil)
  _wrap_assertion do
    assert_respond_to(object, predicate, message)
    actual = object.send(predicate)
    full_message = build_message(message,
                                 "<?>.? is false value expected but was\n" +
                                 "<?>",
                                 object,
                                 AssertionMessage.literal(predicate),
                                 actual)
    assert_block(full_message) do
      not actual
    end
  end
end

#assert_not_same(expected, actual, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 399

def assert_not_same(expected, actual, message="")
  full_message = build_message(message, <<EOT, expected, expected.__id__, actual, actual.__id__)
<?>
with id <?> expected to not be equal\\? to
<?>
with id <?>.
EOT
  assert_block(full_message) { !actual.equal?(expected) }
end

#assert_nothing_raised(*args) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 357

def assert_nothing_raised(*args)
  _wrap_assertion do
    if args.last.is_a?(String)
      message = args.pop
    else
      message = ""
    end

    assert_exception_helper = AssertExceptionHelper.new(self, args)
    begin
      yield
    rescue Exception => e
      if ((args.empty? && !e.instance_of?(AssertionFailedError)) ||
          assert_exception_helper.expected?(e))
        failure_message = build_message(message, "Exception raised:\n?", e)
        assert_block(failure_message) {false}
      else
        raise
      end
    end
    nil
  end
end

#assert_nothing_thrown(message = "", &proc) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 514

def assert_nothing_thrown(message="", &proc)
  _wrap_assertion do
    assert(block_given?, "Should have passed a block to assert_nothing_thrown")
    begin
      proc.call
    rescue NameError, ArgumentError, ThreadError => error
      raise unless UncaughtThrow[error.class] =~ error.message
      tag = $1
      tag = tag[1..-1].intern if tag[0, 1] == ":"
      full_message = build_message(message,
                                   "<?> was thrown when nothing was expected",
                                   tag)
      flunk(full_message)
    end
    assert(true, "Expected nothing to be thrown")
  end
end

#assert_operator(object1, operator, object2, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 335

def assert_operator(object1, operator, object2, message="")
  _wrap_assertion do
    full_message = build_message(nil, "<?>\ngiven as the operator for #assert_operator must be a Symbol or #respond_to\\?(:to_str).", operator)
    assert_block(full_message){operator.kind_of?(Symbol) || operator.respond_to?(:to_str)}
    full_message = build_message(message, <<EOT, object1, AssertionMessage.literal(operator), object2)
<?> expected to be
?
<?>.
EOT
    assert_block(full_message) { object1.__send__(operator, object2) }
  end
end

#assert_predicate(object, predicate, message = nil) ⇒ Object

Passes if object.predicate

Example:

assert_predicate([], :empty?)  # -> pass
assert_predicate([1], :empty?) # -> fail



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# File 'lib/test/unit/assertions.rb', line 763

def assert_predicate(object, predicate, message=nil)
  _wrap_assertion do
    assert_respond_to(object, predicate, message)
    actual = object.send(predicate)
    full_message = build_message(message,
                                 "<?>.? is true value expected but was\n" +
                                 "<?>",
                                 object,
                                 AssertionMessage.literal(predicate),
                                 actual)
    assert_block(full_message) do
      actual
    end
  end
end

#assert_raise(*args, &block) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 117

def assert_raise(*args, &block)
  assert_expected_exception = Proc.new do |*_args|
    message, assert_exception_helper, actual_exception = _args
    expected = assert_exception_helper.expected_exceptions
    full_message = build_message(message,
                                 "<?> exception expected but was\n?",
                                 expected, actual_exception)
    assert_block(full_message) do
      expected == [] or assert_exception_helper.expected?(actual_exception)
    end
  end
  _assert_raise(assert_expected_exception, *args, &block)
end

#assert_raise_kind_of(*args, &block) ⇒ Object

Passes if the block raises one of the given exceptions or sub exceptions of the given exceptions.

Example:

assert_raise_kind_of(SystemCallError) do
  raise Errno::EACCES
end



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# File 'lib/test/unit/assertions.rb', line 149

def assert_raise_kind_of(*args, &block)
  assert_expected_exception = Proc.new do |*_args|
    message, assert_exception_helper, actual_exception = _args
    expected = assert_exception_helper.expected_exceptions
    full_message = build_message(message,
                                 "<?> family exception expected " +
                                 "but was\n?",
                                 expected, actual_exception)
    assert_block(full_message) do
      assert_exception_helper.expected?(actual_exception, :kind_of?)
    end
  end
  _assert_raise(assert_expected_exception, *args, &block)
end

#assert_raise_message(expected, message = nil) ⇒ Object

Passes if an exception is raised in block and its message is expected.

Example:

assert_raise_message("exception") {raise "exception"}  # -> pass
assert_raise_message(/exc/i) {raise "exception"}       # -> pass
assert_raise_message("exception") {raise "EXCEPTION"}  # -> fail
assert_raise_message("exception") {}                   # -> fail



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# File 'lib/test/unit/assertions.rb', line 691

def assert_raise_message(expected, message=nil)
  _wrap_assertion do
    full_message = build_message(message,
                                 "<?> exception message expected " +
                                 "but none was thrown.",
                                 expected)
    exception = nil
    assert_block(full_message) do
      begin
        yield
        false
      rescue Exception => exception
        true
      end
    end

    actual = exception.message
    diff = AssertionMessage.delayed_diff(expected, actual)
    full_message =
      build_message(message,
                    "<?> exception message expected but was\n" +
                    "<?>.?", expected, actual, diff)
    assert_block(full_message) do
      if expected.is_a?(Regexp)
        expected =~ actual
      else
        expected == actual
      end
    end
  end
end

#assert_raises(*args, &block) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 137

def assert_raises(*args, &block)
  assert_raise(*args, &block)
end

#assert_respond_to(object, method, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 270

def assert_respond_to(object, method, message="")
  _wrap_assertion do
    full_message = build_message(message,
                                 "<?>.kind_of\\?(Symbol) or\n" +
                                 "<?>.respond_to\\?(:to_str) expected",
                                 method, method)
    assert_block(full_message) do
      method.kind_of?(Symbol) or method.respond_to?(:to_str)
    end
    full_message = build_message(message,
                                 "<?>.respond_to\\?(?) expected\n" +
                                 "(Class: <?>)",
                                 object, method, object.class)
    assert_block(full_message) {object.respond_to?(method)}
  end
end

#assert_same(expected, actual, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 316

def assert_same(expected, actual, message="")
  full_message = build_message(message, <<EOT, expected, expected.__id__, actual, actual.__id__)
<?>
with id <?> expected to be equal\\? to
<?>
with id <?>.
EOT
  assert_block(full_message) { actual.equal?(expected) }
end

#assert_send(send_array, message = "") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 567

def assert_send(send_array, message="")
  _wrap_assertion do
    assert_instance_of(Array, send_array, "assert_send requires an array of send information")
    assert(send_array.size >= 2, "assert_send requires at least a receiver and a message name")
    full_message = build_message(message, <<EOT, send_array[0], AssertionMessage.literal(send_array[1].to_s), send_array[2..-1])
<?> expected to respond to
<?(?)> with a true value.
EOT
    assert_block(full_message) { send_array[0].__send__(send_array[1], *send_array[2..-1]) }
  end
end

#assert_throw(expected_object, message = "", &proc) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 463

def assert_throw(expected_object, message="", &proc)
  _wrap_assertion do
    begin
      catch([]) {}
    rescue TypeError
      assert_instance_of(Symbol, expected_object,
                         "assert_throws expects the symbol that should be thrown for its first argument")
    end
    assert_block("Should have passed a block to assert_throw.") do
      block_given?
    end
    caught = true
    begin
      catch(expected_object) do
        proc.call
        caught = false
      end
      full_message = build_message(message,
                                   "<?> should have been thrown.",
                                   expected_object)
      assert_block(full_message) {caught}
    rescue NameError, ArgumentError, ThreadError => error
      raise unless UncaughtThrow[error.class] =~ error.message
      tag = $1
      tag = tag[1..-1].intern if tag[0, 1] == ":"
      full_message = build_message(message,
                                   "<?> expected to be thrown but\n" +
                                   "<?> was thrown.",
                                   expected_object, tag)
      flunk(full_message)
    end
  end
end

#assert_throws(*args, &block) ⇒ Object

Alias of assert_throw.

Will be deprecated in 1.9, and removed in 2.0.



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# File 'lib/test/unit/assertions.rb', line 501

def assert_throws(*args, &block)
  assert_throw(*args, &block)
end

#assert_true(actual, message = nil) ⇒ Object

Passes if actual is true.

Example:

assert_true(true)  # -> pass
assert_true(:true) # -> fail



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# File 'lib/test/unit/assertions.rb', line 601

def assert_true(actual, message=nil)
  _wrap_assertion do
    assert_block(build_message(message,
                               "<true> expected but was\n<?>",
                               actual)) do
      actual == true
    end
  end
end

#build_message(head, template = nil, *arguments) ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 854

def build_message(head, template=nil, *arguments)
  template &&= template.chomp
  return AssertionMessage.new(head, template, arguments)
end

#flunk(message = "Flunked") ⇒ Object 



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# File 'lib/test/unit/assertions.rb', line 388

def flunk(message="Flunked")
  assert_block(build_message(message)){false}
end