[Fix #292] ensure all kinds of assignments are correctly handled when…

… counting assertions

changelog/fix_ensure_all_kinds_of_assignments_are.md

@@ -0,0 +1 @@
+* [#292](https://github.com/rubocop/rubocop-minitest/issues/292): Ensure all kinds of assignments are correctly handled when counting assertions. ([@G-Rath][])

lib/rubocop/cop/minitest/multiple_assertions.rb

@@ -74,11 +74,21 @@ def assertions_count_based_on_type(node)
  end
 
  def assertions_count_in_assignment(node)
- # checking the direct expression is handled by assertion_method?
- return 0 unless node.expression.block_type? || node.expression.numblock_type?
+ return assertions_count_based_on_type(node.expression) unless node.masgn_type?
 
- # this will only trigger the branches for :block and :numblock type nodes
- assertions_count_based_on_type(node.expression)
+ rhs = node.children.last
+
+ case rhs.type
+ when :array
+ rhs.children.sum { |child| assertions_count_based_on_type(child) }
+ when :send
+ assertion_method?(rhs) ? 1 : 0
+ else
+ # Play it safe and bail if we don't have any explicit handling for whatever
+ # the RHS type is, since at this point we're already probably dealing with
+ # a pretty exotic situation that's unlikely in the real world.
+ 0
+ end
  end
 
  def assertions_count_in_branches(branches)

test/rubocop/cop/minitest/multiple_assertions_test.rb

@@ -113,6 +113,49 @@ def test_asserts_once
  RUBY
  end
 
+ def test_does_not_crash_with_mass_assignments
+ assert_no_offenses(<<~RUBY)
+ class FooTest < Minitest::Test
+ def test_does_not_crash
+ _, _ = foo
+ _, _ = []
+ _, _ = {}
+ _, _ = ''
+ _, _ = 1
+ end
+ end
+ RUBY
+ end
+
+ def test_all_types_of_assignments_are_understood
+ assert_offense(<<~RUBY)
+ class FooTest < Minitest::Test
+ def test_all_types_of_assignment
+ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Test case has too many assertions [8/1].
+ # lvasgn
+ foo = assert_equal(1, 1)
+ # ivasgn
+ @instance_variable = assert_equal(1, 1)
+ # cvasgn
+ @@class_variable = assert_equal(1, 1)
+ # gvasgn
+ $global_variable = assert_equal(1, 1)
+ # casgn
+ # MyClass::CONSTANT_VALUE = assert_equal(1, 1)
+ # masgn
+ a, b, c = assert_equal(1, 1)
+ a, b, c = [assert_equal(1, 1), assert_equal(1, 1), assert_equal(1, 1)]
+ # op_asgn
+ counter += assert_equal(1, 1)
+ # or_asgn
+ result ||= assert_equal(1, 1)
+ # and_asgn
+ flag &&= assert_equal(1, 1)
+ end
+ end
+ RUBY
+ end
+
  def test_assignments_are_not_counted_twice
  assert_no_offenses(<<~RUBY)
  class FooTest < Minitest::Test
@@ -295,6 +338,22 @@ class FooTest < ActiveSupport::TestCase
  RUBY
  end
 
+ def test_registers_offense_when_multiple_assertions_inside_assigned_conditional
+ assert_offense(<<~RUBY)
+ class FooTest < ActiveSupport::TestCase
+ test 'something' do
+ ^^^^^^^^^^^^^^^^^^^ Test case has too many assertions [2/1].
+ _ = if condition
+ assert_equal(foo, bar) # 1
+ assert_empty(array) # 2
+ else
+ assert_equal(foo, baz)
+ end
+ end
+ end
+ RUBY
+ end
+
  def test_does_not_register_offense_when_single_assertion_inside_conditional
  assert_no_offenses(<<~RUBY)
  class FooTest < ActiveSupport::TestCase
@@ -330,6 +389,27 @@ class FooTest < ActiveSupport::TestCase
  RUBY
  end
 
+ def test_registers_offense_when_multiple_expectations_inside_assigned_case
+ assert_offense(<<~RUBY)
+ class FooTest < ActiveSupport::TestCase
+ test 'something' do
+ ^^^^^^^^^^^^^^^^^^^ Test case has too many assertions [3/1].
+ _ = case
+ when condition1
+ assert_equal(foo, bar)
+ assert_empty(array)
+ when condition2
+ assert_equal(foo, bar) # 1
+ assert_empty(array) # 2
+ assert_equal(foo, baz) # 3
+ else
+ assert_equal(foo, zoo)
+ end
+ end
+ end
+ RUBY
+ end
+
  def test_does_not_register_offense_when_single_assertion_inside_case
  assert_no_offenses(<<~RUBY)
  class FooTest < ActiveSupport::TestCase
@@ -366,6 +446,27 @@ class FooTest < ActiveSupport::TestCase
  RUBY
  end
 
+ def test_registers_offense_when_multiple_expectations_inside_assigned_pattern_matching
+ assert_offense(<<~RUBY)
+ class FooTest < ActiveSupport::TestCase
+ test 'something' do
+ ^^^^^^^^^^^^^^^^^^^ Test case has too many assertions [3/1].
+ _ = case variable
+ in pattern1
+ assert_equal(foo, bar)
+ assert_empty(array)
+ in pattern2
+ assert_equal(foo, bar) # 1
+ assert_empty(array) # 2
+ assert_equal(foo, baz) # 3
+ else
+ assert_equal(foo, zoo)
+ end
+ end
+ end
+ RUBY
+ end
+
  def test_does_not_register_offense_when_single_assertion_inside_pattern_matching
  assert_no_offenses(<<~RUBY)
  class FooTest < ActiveSupport::TestCase
@@ -399,6 +500,26 @@ class FooTest < ActiveSupport::TestCase
  RUBY
  end
 
+ def test_registers_offense_when_multiple_expectations_inside_assigned_rescue
+ assert_offense(<<~RUBY)
+ class FooTest < ActiveSupport::TestCase
+ test 'something' do
+ ^^^^^^^^^^^^^^^^^^^ Test case has too many assertions [3/1].
+ _ = begin
+ do_something
+ rescue Foo
+ assert_equal(foo, bar)
+ assert_empty(array)
+ rescue Bar
+ assert_equal(foo, bar) # 1
+ assert_empty(array) # 2
+ assert_equal(foo, baz) # 3
+ end
+ end
+ end
+ RUBY
+ end
+
  def test_does_not_register_offense_when_single_assertion_inside_rescue
  assert_no_offenses(<<~RUBY)
  class FooTest < ActiveSupport::TestCase
@@ -450,6 +571,86 @@ class FooTest < ActiveSupport::TestCase
  RUBY
  end
 
+ def test_registers_offense_when_complex_structure_with_assignments_and_multiple_assertions
+ configure_max_assertions(2)
+
+ assert_offense(<<~RUBY)
+ class FooTest < ActiveSupport::TestCase
+ test 'something' do
+ ^^^^^^^^^^^^^^^^^^^ Test case has too many assertions [4/2].
+ _= if condition1
+ assert foo
+ elsif condition2
+ assert foo
+ else
+ begin
+ do_something
+ assert foo # 1
+ rescue Foo
+ assert foo
+ assert foo
+ rescue Bar
+ # noop
+ rescue Zoo
+ _ = case
+ when condition
+ assert foo # 2
+ assert foo # 3
+ assert foo # 4
+ else
+ assert foo
+ assert foo
+ end
+ else
+ assert foo
+ end
+ end
+ end
+ end
+ RUBY
+ end
+
+ def test_registers_offense_when_complex_multiple_assignment_structure_and_multiple_assertions
+ configure_max_assertions(2)
+
+ assert_offense(<<~RUBY)
+ class FooTest < ActiveSupport::TestCase
+ test 'something' do
+ ^^^^^^^^^^^^^^^^^^^ Test case has too many assertions [5/2].
+ _, _, _ = [
+ if condition1
+ assert foo
+ else
+ assert foo
+ end,
+ begin
+ do_something
+ assert foo # 1
+ rescue Foo
+ assert foo
+ assert foo
+ rescue Bar
+ # noop
+ rescue Zoo
+ _ = case
+ when condition
+ assert foo # 2
+ assert foo # 3
+ assert foo # 4
+ else
+ assert foo
+ assert foo
+ end
+ else
+ assert foo
+ end,
+ assert(foo)
+ ]
+ end
+ end
+ RUBY
+ end
+
  def test_does_not_register_offense_when_complex_structure_with_single_assertion
  assert_no_offenses(<<~RUBY)
  class FooTest < ActiveSupport::TestCase