# Schema Assignment Fixture
The schema assignment fixture tests that a schema instance's attributes have been assigned a value. The fixture is used to make sure that a schema object's attributes have been mutated in the course of some procedure.
If an attribute is declared with a default value, then the attribute must have been assigned another value for it to be considered mutated.
By default, all of schema object's attributes are asserted to have been mutated. An optional list of attribute names can be passed. When the list of attribute names is passed, only those attributes will be compared.
class Something include Schema attribute :some_attribute attribute :some_other_attribute end context 'Assigned' do example = Something.new example.some_attribute = 'some value' example.some_other_attribute = 'some other value' fixture(Assignment, example) end
# Schema Assignment Fixture Facts
- The principle concern of a schema assignment fixture test is the assurance that a schema object's attributes have been mutated
- An optional list of attribute names can given to limit the attribute assignment tests to a subset of attributes
# Schema::Fixtures::Assignment Class
Assignment class is a concrete class from the
Schema::Fixtures library and namespace.
Schema::Fixtures::Assignment class provides:
- The instance actuator
callmethod) that begins execution of the fixture and the testing of schema attribute assignment
# Running the Fixture
Running the test is no different than running any TestBench test (opens new window).
For example, given a test file named
schema_assignment.rb that uses the schema assignment fixture, in a directory named
test, the test is executed by passing the file name to the
The test script and the fixture work together as if they are part of the same test context, preserving output nesting between the test script file and the test fixture.
# Schema Assignment Fixture Output
Assigned Schema Assignment: Example Attributes some_attribute some_other_attribute
# Detailed Output
In the event of any error or failed assertion, the test output will include additional detailed output that can be useful in understanding the context of the failure and the state of the fixture itself and the objects that it's testing.
The detailed output can also be printed by setting the
TEST_BENCH_DETAIL environment variable to
TEST_BENCH_DETAIL=on ruby test/schema_assignment.rb
Assigned Schema Assignment: Example Class: Something::Example Attributes some_attribute Default Value: nil Assigned Value: "some value" some_other_attribute Default Value: nil Assigned Value: "some other value"
# Actuating the Assignment Fixture
The fixture is executed using TestBench's
fixture(Schema::Fixtures::Assignment, schema, attribute_names=nil)
The first argument sent to the
fixture method is always the
Schema::Fixtures::Assignment class. Subsequent arguments are the specific construction parameters of the assignment fixture.
When the list of attribute names is not provided, it defaults to the list of all of the names of the schema object's attributes.
|schema||The schema object whose attributes will be tested for assignment||Schema|
|attribute_names||Optional list of attribute names to check for assignment||Array of Symbol|
# Limiting the Test to a Subset of Attributes
The Assignment fixture can limit the attribute tests to a subset of attributes by specifying a list of attribute names.
context 'Equal' do example = Something::Example.new example.some_attribute = 'some value' attribute_names = [:some_attribute] fixture(Assignment, example, attribute_names) end
Assigned Schema Assignment: Example Attributes some_attribute
# Determination of Assignment and Default Values
An attribute is determined to have been assigned a value if the attribute's value is no longer equal to its default value.
An attribute's default value may be defined as something other than
If an attribute has been explicitly assigned a value that is equal to its default value, it's considered to have not been assigned at all, which is considered a failed assignment test.
In order for assignment tests to pass, the value of attributes have to be other than their default values.
module DefaultValue class Example include ::Schema attribute :some_attribute, default: 'some default value' attribute :some_other_attribute end end context 'Assigned' do example = DefaultValue::Example.new example.some_attribute = 'some default value' example.some_other_attribute = nil fixture(Assignment, example) end
Assigned Schema Assignment: Example Class: DefaultValue::Example Attributes some_attribute Default Value: 'some default value' Assigned Value: 'some default value' /schema-fixtures/lib/schema/fixtures/assignment.rb:30:in `block (4 levels) in call': Assertion failed (TestBench::Fixture::AssertionFailure) some_other_attribute Default Value: nil Assigned Value: nil /schema-fixtures/lib/schema/fixtures/assignment.rb:30:in `block (4 levels) in call': Assertion failed (TestBench::Fixture::AssertionFailure)