randoop.generation

Class ForwardGenerator

java.lang.Object

randoop.generation.AbstractGenerator

randoop.generation.ForwardGenerator

public class ForwardGenerator
extends AbstractGenerator

Randoop's forward, component-based generator.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	ForwardGenerator.VarAndSeq

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.LinkedHashSet<Sequence>	allSequences The set of ALL sequences ever generated, including sequences that were executed and then discarded.
private java.util.List<java.lang.String>	allsequencesAsCode Set and used only if GenInputsAbstract.debug_checks==true.
private java.util.List<Sequence>	allsequencesAsList Set and used only if GenInputsAbstract.debug_checks==true.
private InputSequenceSelector	inputSequenceSelector How to select sequences as input for creating new sequences.
private TypeInstantiator	instantiator
private TypedOperationSelector	operationSelector How to select the method to use for creating a new sequence.
private java.util.Set<java.lang.Object>	runtimePrimitivesSeen The set of all primitive values seen during generation and execution of sequences.
private java.util.Set<TypedOperation>	sideEffectFreeMethods The side-effect-free methods.

Fields inherited from class randoop.generation.AbstractGenerator

checkGenerator, componentManager, currSeq, dump_sequences, executionVisitor, invalidSequenceCount, limits, null_steps, num_failed_output_test, num_failing_sequences, num_sequences_generated, num_steps, operationHistory, operations, outErrorSeqs, outputTest, outRegressionSeqs, subsumed_sequences

Constructor Summary

Constructors

Constructor and Description
ForwardGenerator(java.util.List<TypedOperation> operations, java.util.Set<TypedOperation> sideEffectFreeMethods, GenInputsAbstract.Limits limits, ComponentManager componentManager, IStopper stopper, java.util.Set<ClassOrInterfaceType> classesUnderTest) Create a forward generator.
ForwardGenerator(java.util.List<TypedOperation> operations, java.util.Set<TypedOperation> sideEffectFreeMethods, GenInputsAbstract.Limits limits, ComponentManager componentManager, java.util.Set<ClassOrInterfaceType> classesUnderTest) Create a forward generator.

Method Summary

Modifier and Type	Method and Description
private ExecutableSequence	createNewUniqueSequence() Tries to create a new sequence.
private void	determineActiveIndices(ExecutableSequence seq) Determines what indices in the given sequence are active.
java.util.Set<Sequence>	getAllSequences() Return all sequences generated by this object.
private void	initializeRuntimePrimitivesSeen() The runtimePrimitivesSeen set contains primitive values seen during generation/execution and is used to determine new values that should be added to the component set.
void	newRegressionTestHook(Sequence sequence) Take action based on the given Sequence that was classified as a regression test.
int	numGeneratedSequences() Returns the count of sequences generated so far by the generator.
(package private) ForwardGenerator.VarAndSeq	randomVariable(SimpleList<Sequence> candidates, Type inputType, boolean isReceiver) Return a variable of the given type.
private void	randoopConsistencyTest2(Sequence newSequence)
private void	randoopConsistencyTests(Sequence newSequence)
private Sequence	repeat(Sequence seq, TypedOperation operation, int times) Adds the given operation to a new Sequence with the statements of this object as a prefix, repeating the operation the given number of times.
private InputsAndSuccessFlag	selectInputs(TypedOperation operation) This method is responsible for doing two things: Selecting at random a collection of sequences that can be used to create input values for the given statement, and Selecting at random valid indices to the above sequence specifying the values to be used as input to the statement.
@Nullable ExecutableSequence	step() Attempt to generate a test (a sequence).
java.lang.String	toString()

Methods inherited from class randoop.generation.AbstractGenerator

createAndClassifySequences, getErrorTestSequences, getOperationHistory, getRegressionSequences, numAttemptedSequences, numOutputSequences, outputSequenceCount, setCurrentSequence, setExecutionVisitor, setExecutionVisitor, setOperationHistoryLogger, setTestCheckGenerator, setTestPredicate, shouldStop

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

allSequences

private final java.util.LinkedHashSet<Sequence> allSequences

The set of ALL sequences ever generated, including sequences that were executed and then discarded.

This must be ordered by insertion to allow for flaky test history collection in GenTests.printSequenceExceptionError(AbstractGenerator, SequenceExceptionError).

sideEffectFreeMethods

private final java.util.Set<TypedOperation> sideEffectFreeMethods

The side-effect-free methods.

allsequencesAsCode

private final java.util.List<java.lang.String> allsequencesAsCode

Set and used only if GenInputsAbstract.debug_checks==true. This contains the same components as allSequences, in the same order, but stores them as strings obtained via the toCodeString() method.

allsequencesAsList

private final java.util.List<Sequence> allsequencesAsList

Set and used only if GenInputsAbstract.debug_checks==true. This contains the same components as allSequences, in the same order, but can be accessed by index.

instantiator

private final TypeInstantiator instantiator

inputSequenceSelector

private final InputSequenceSelector inputSequenceSelector

How to select sequences as input for creating new sequences.

operationSelector

private final TypedOperationSelector operationSelector

How to select the method to use for creating a new sequence.

runtimePrimitivesSeen

private java.util.Set<java.lang.Object> runtimePrimitivesSeen

The set of all primitive values seen during generation and execution of sequences. This set is used to tell if a new primitive value has been generated, to add the value to the components.

Each value in the collection is a primitive wrapper or a String.

Constructor Detail

ForwardGenerator

public ForwardGenerator(java.util.List<TypedOperation> operations,
                        java.util.Set<TypedOperation> sideEffectFreeMethods,
                        GenInputsAbstract.Limits limits,
                        ComponentManager componentManager,
                        java.util.Set<ClassOrInterfaceType> classesUnderTest)

Create a forward generator.

Parameters:

operations - list of operations under test

sideEffectFreeMethods - side-effect-free methods

limits - limits for generation, after which the generator will stop

componentManager - stores previously-generated sequences

classesUnderTest - set of classes under test

ForwardGenerator

public ForwardGenerator(java.util.List<TypedOperation> operations,
                        java.util.Set<TypedOperation> sideEffectFreeMethods,
                        GenInputsAbstract.Limits limits,
                        ComponentManager componentManager,
                        IStopper stopper,
                        java.util.Set<ClassOrInterfaceType> classesUnderTest)

Create a forward generator.

Parameters:

operations - list of methods under test

sideEffectFreeMethods - side-effect-free methods

limits - limits for generation, after which the generator will stop

componentManager - container for sequences that are used to generate new sequences

stopper - determines when the test generation process should conclude. Can be null.

classesUnderTest - the classes that are under test

Method Detail

newRegressionTestHook

public void newRegressionTestHook(Sequence sequence)

Take action based on the given Sequence that was classified as a regression test.

Specified by:

newRegressionTestHook in class AbstractGenerator

Parameters:

sequence - the new sequence that was classified as a regression test

initializeRuntimePrimitivesSeen

private void initializeRuntimePrimitivesSeen()

The runtimePrimitivesSeen set contains primitive values seen during generation/execution and is used to determine new values that should be added to the component set. The component set initially contains a set of primitive sequences; this method puts those primitives in this set.

step

public @Nullable ExecutableSequence step()

Description copied from class: AbstractGenerator

Attempt to generate a test (a sequence).

Specified by:

step in class AbstractGenerator

Returns:

a test sequence, may be null

getAllSequences

public java.util.Set<Sequence> getAllSequences()

Description copied from class: AbstractGenerator

Return all sequences generated by this object.

Specified by:

getAllSequences in class AbstractGenerator

Returns:

all generated sequences

determineActiveIndices

private void determineActiveIndices(ExecutableSequence seq)

Determines what indices in the given sequence are active. (Actually, sets some indices as not active, since the default is that every index is active.)

An active index i means that the i-th method call creates an interesting/useful value that can be used as an input to a larger sequence; inactive indices are never used as inputs. The SequenceCollection to which the given sequences is added only considers the active indices when deciding whether the sequence creates values of a given type.

In addition to determining active indices, this method determines if any primitive values created during execution of the sequence are new values not encountered before. Such values are added to the component manager so they can be used during subsequent generation attempts.

Parameters:

seq - the sequence, all of whose indices are initially marked as active

createNewUniqueSequence

private ExecutableSequence createNewUniqueSequence()

Tries to create a new sequence. If the sequence is new (not already in the specified component manager), then adds it to the manager's sequences.

This method returns null if:

• it selects an operation but cannot generate inputs for the operation
• it creates too large a method
• it creates a duplicate sequence

This method modifies the list of operations that represent the set of methods under tests. Specifically, if the selected operation used for creating a new and unique sequence is a parameterless operation (a static constant method or no-argument constructor) it is removed from the list of operations. Such a method will return the same thing every time it is invoked (unless it's nondeterministic, but Randoop should not be run on nondeterministic methods). Once invoked, its result is in the pool and there is no need to call the operation again and so we will remove it from the list of operations.

Returns:

a new sequence, or null

repeat

private Sequence repeat(Sequence seq,
                        TypedOperation operation,
                        int times)

Adds the given operation to a new Sequence with the statements of this object as a prefix, repeating the operation the given number of times. Used during generation.

Parameters:

seq - the sequence to extend

operation - the TypedOperation to repeat

times - the number of times to repeat the Operation

Returns:

a new Sequence

randoopConsistencyTest2

private void randoopConsistencyTest2(Sequence newSequence)

randoopConsistencyTests

private void randoopConsistencyTests(Sequence newSequence)

selectInputs

private InputsAndSuccessFlag selectInputs(TypedOperation operation)

This method is responsible for doing two things:

1. Selecting at random a collection of sequences that can be used to create input values for the given statement, and
2. Selecting at random valid indices to the above sequence specifying the values to be used as input to the statement.

The selected sequences and indices are wrapped in an InputsAndSuccessFlag object and returned. If an appropriate collection of sequences and indices was not found (e.g. because there are no sequences in the componentManager that create values of some type required by the statement), the success flag of the returned object is false.

Parameters:

operation - the statement to analyze

Returns:

the selected sequences and indices

randomVariable

ForwardGenerator.VarAndSeq randomVariable(SimpleList<Sequence> candidates,
                                          Type inputType,
                                          boolean isReceiver)

Return a variable of the given type.

Parameters:

candidates - sequences, each of which produces a value of type inputType; that is, each would be a legal return value

inputType - the type of the chosen variable/sequence

isReceiver - whether the value will be used as a receiver

Returns:

a random variable of the given type, chosen from the candidates

numGeneratedSequences

public int numGeneratedSequences()

Description copied from class: AbstractGenerator

Returns the count of sequences generated so far by the generator.

Specified by:

numGeneratedSequences in class AbstractGenerator

Returns:

the number of sequences generated

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object