instance method `stub_const`

Ruby on Rails 7.1.6

Since v7.1.6

Available in: v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

stub_const(mod, constant, new_value)

Changes the value of a constant for the duration of a block. Example:

# World::List::Import::LARGE_IMPORT_THRESHOLD = 5000
stub_const(World::List::Import, :LARGE_IMPORT_THRESHOLD, 1) do
  assert_equal 1, World::List::Import::LARGE_IMPORT_THRESHOLD
end

assert_equal 5000, World::List::Import::LARGE_IMPORT_THRESHOLD

Using this method rather than forcing World::List::Import::LARGE_IMPORT_THRESHOLD = 5000 prevents warnings from being thrown, and ensures that the old value is returned after the test has completed.

Note: Stubbing a const will stub it across all threads. So if you have concurrent threads (like separate test suites running in parallel) that all depend on the same constant, it’s possible divergent stubbing will trample on each other.

Parameters

mod req
constant req
new_value req

Source

# File activesupport/lib/active_support/testing/constant_stubbing.rb, line 21
      def stub_const(mod, constant, new_value)
        old_value = mod.const_get(constant, false)
        mod.send(:remove_const, constant)
        mod.const_set(constant, new_value)
        yield
      ensure
        mod.send(:remove_const, constant)
        mod.const_set(constant, old_value)
      end

Defined in activesupport/lib/active_support/testing/constant_stubbing.rb line 21 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveSupport::Testing::ConstantStubbing

Signature

Parameters