uk.ac.sheffield.vtts.model

Class TestSequence

java.lang.Object

uk.ac.sheffield.vtts.model.Element

uk.ac.sheffield.vtts.model.Sequence

uk.ac.sheffield.vtts.model.TestSequence

All Implemented Interfaces:

java.lang.Comparable<TestSequence>

public class TestSequence
extends Sequence
implements java.lang.Comparable<TestSequence>

TestSequence represents a test whose steps are to be executed in order. A TestSequence is the more concrete realisation of an abstract Sequence, whose symbolic Events are realised as concrete TestSteps. A TestSequence contains a list of TestSteps, representing a sequence of operations to invoke on the system under test. The prefix TestSteps represent set-up instructions and the final TestStep is the verified step, which must be checked using assertions. A TestSequence records the system State that it is testing, and the Transition path length that it is testing. It is also indexed with a test-number.

A TestSequence may optionally be merged with shorter TestSequences that are a prefix of this TestSequence. In this case, multiple TestSteps may be verified, and this TestSequence represents a multi-objective test. TestSequences are comparable objects that can be sorted according to their precedence during testing. By default, shorter TestSequences precede longer tests; but multi-objective TestSequences precede other tests if they verify more objectives. This property ensures that testing is properly ordered, such that fundamental system properties are tested before dependent properties.

Version:

Broker@Cloud 1.0

Author:

Anthony J H Simons

Field Summary

Fields inherited from class uk.ac.sheffield.vtts.model.Sequence

events, path, state

Constructor Summary

Constructors

Constructor and Description
TestSequence() Constructs an empty TestSequence.
TestSequence(Sequence sequence) Constructs an empty TestSequence covering the same state and path as the coverage Sequence.

Method Summary

Methods

Modifier and Type	Method and Description
int	compareTo(TestSequence other) Compares one TestSequence with another, as part of a sorting algorithm.
int	countVerify() Counts the number of verified TestSteps in this TestSequence.
TestSequence	doVerify() Verify the outcome of this TestSequence.
java.lang.String	getSource() Returns the name of the expected source State.
java.lang.String	getTarget() Returns the name of the expected target State.
int	getTest() Returns the test index of this TestSequence.
java.util.List<TestStep>	getTestSteps() Returns the ordered list of TestSteps.
boolean	hasFailures() Reports whether this TestSequence can possibly raise anticipated Exceptions.
boolean	hasPrefix(TestSequence other) Reports whether this TestSequence contains the other as a prefix.
boolean	mergePrefix(TestSequence prefix) Optionally merges a prefix TestSequence with this TestSequence.
void	receive(Grounding grounding) Receive a Grounding generator for grounding this TestSequence.
TestSequence	setTest(int test) Sets the test index of this TestSequence.

Methods inherited from class uk.ac.sheffield.vtts.model.Sequence

addEvent, addSequence, equals, getEvents, getFirstEvent, getLastEvent, getPath, getState, hashCode, isEmpty, setPath, setState, size

Methods inherited from class uk.ac.sheffield.vtts.model.Element

safeEquals, safeHashCode, semanticError

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TestSequence

public TestSequence()

Constructs an empty TestSequence.

TestSequence

public TestSequence(Sequence sequence)

Constructs an empty TestSequence covering the same state and path as the coverage Sequence.

Parameters:

sequence - a coverage Sequence.

Method Detail

getTest

public int getTest()

Returns the test index of this TestSequence.

Returns:

the test index.

setTest

public TestSequence setTest(int test)

Sets the test index of this TestSequence.

Parameters:

test - the test index to set.

Returns:

this TestSequence.

getTestSteps

public java.util.List<TestStep> getTestSteps()

Returns the ordered list of TestSteps. Provided for convenience, since the inherited method returns an ordered list of Events.

Returns:

the list of TestSteps.

hasFailures

public boolean hasFailures()

Reports whether this TestSequence can possibly raise anticipated Exceptions. Checks each TestStep to see whether its invoked Operation has a signature that can possibly return one or more Failures. If so, checks each Failure to see if it is bound (representing a required exception that will be caught) or unbound (representing an uncaught exception). Returns true if there is any uncaught exception.

Returns:

true if this TestSequence can raise anticipated Exceptions.

hasPrefix

public boolean hasPrefix(TestSequence other)

Reports whether this TestSequence contains the other as a prefix. Returns true if the other TestSequence is a prefix of this one, that is, if its whole sequence of Events is equal to some initial sequence of Events in this TestSequence. Returns false immediately if the two TestSequences are identical, or if the other is not shorter than this TestSequence. Otherwise, compares Events pair-wise according to the definition of Event equality.

Parameters:

other - the other TestSequence

Returns:

true, if the other is a prefix of this TestSequence.

mergePrefix

public boolean mergePrefix(TestSequence prefix)

Optionally merges a prefix TestSequence with this TestSequence. If the candidate prefix is in fact a prefix of this TestSequence, copies its verified obligations across to this TestSequence and returns true; otherwise returns false. If the merge succeeds, this TestSequence becomes a multi-objective test, with more than one verified TestStep, which also fulfils the verified obligations of the merged TestSequence.

Parameters:

prefix - the prefix TestSequence.

Returns:

true if the prefix was merged.

doVerify

public TestSequence doVerify()

Verify the outcome of this TestSequence. Sets the checked property of the final TestStep in this TestSequence to true. Does nothing if this TestSequence is empty.

Returns:

this TestSequence.

getSource

public java.lang.String getSource()

Returns the name of the expected source State. Returns the name of the State reached by the first initialising TestStep.

Returns:

the name of the source State.

getTarget

public java.lang.String getTarget()

Returns the name of the expected target State. Returns the name of the State reached by the last TestStep in this TestSequence.

Returns:

the name of the target State.

countVerify

public int countVerify()

Counts the number of verified TestSteps in this TestSequence.

Returns:

the number of verified TestSteps.

compareTo

public int compareTo(TestSequence other)

Compares one TestSequence with another, as part of a sorting algorithm. By default, a shorter TestSequence precedes every longer TestSequence, of which it could be a prefix. However, when sorting multi-objective tests, a TestSequence with multiple verified steps should precede a TestSequence with fewer verified steps, since the sequence with more verified steps contains its own prefix tests. This rule takes priority over the default rule, which applies when two TestSequences have the same number of verified steps.

Specified by:

compareTo in interface java.lang.Comparable<TestSequence>

Parameters:

other - the other TestSequence.

Returns:

a negative, zero or positive value, denoting respectively that this TestSequence precedes, is equal in rank to, or follows the other.

See Also:

Comparable.compareTo(java.lang.Object)

receive

public void receive(Grounding grounding)

Receive a Grounding generator for grounding this TestSequence. The actual generator is any class that implements the Grounding interface. Asks the grounding reciprocally to ground this TestSequence.

Parameters:

grounding - a Grounding generator.