Package randoop.condition

Class ExpectedOutcomeTable

java.lang.Object

randoop.condition.ExpectedOutcomeTable

public class ExpectedOutcomeTable
extends Object

An ExpectedOutcomeTable collects all the permitted outcomes for a set of methods (where the methods are all in an overriding relationship) and a set of prestate values. The set of expected or permitted outcomes is those whose preconditions or conditions are satisfied.

A method implementation must satisfy not only the specification written on it, but also any written on method declarations that it overrides or implements.

One possible implementation would be to record a collection of single-method outcomes, where each single-method outcome represents checks of the prestate ExecutableBooleanExpressions: for the Precondition, the GuardPropertyPair, and GuardThrowsPair for an operation call. ExpectedOutcomeTable is not implemented that way: it does some pre-processing and throws away certain of the information as it is added. (It's unclear whether this is the best choice, or whether the more straightforward implementation would enable simpler and more understandable code at the cost of a bit of extra processing to be done later.)

This implementation records:

1. Whether any guard expression for the Precondition fails, or all are satisfied.
2. The set of ThrowsCondition objects for expected exceptions. An exception is expected if the guard of a GuardThrowsPair is satisfied.
3. The expected postcondition (an ExecutableBooleanExpression), if any.

To create an ExpectedOutcomeTable, call ExecutableSpecification.checkPrestate(Object[]). To use an ExpectedOutcomeTable, call addPostCheckGenerator(TestCheckGenerator) to create a TestCheckGenerator that classifies a method call as follows:

1. For each table entry with a non-empty expected exception set
   • If an exception is thrown by the call and the thrown exception is a member of the set, then classify as GenInputsAbstract.BehaviorType.EXPECTED.
   • If an exception is thrown by the call and the thrown exception is not a member of the set, classify as GenInputsAbstract.BehaviorType.ERROR (because the specification required an exception to be thrown, but it was not thrown).
   • If no exception is thrown, then classify as GenInputsAbstract.BehaviorType.ERROR.
2. If for each table entry, the preconditions failed, classify as GenInputsAbstract.BehaviorType.INVALID.
3. For each table entry where all preconditions were satisfied, check the corresponding normal post-condition property, if one exists. If any such property fails, then classify as GenInputsAbstract.BehaviorType.ERROR.
4. Otherwise, don't classify (let classification fall through).

Field Summary

Fields

Modifier and Type	Field	Description
private List<List<ThrowsClause>>	exceptionSets	The list of lists of throws clauses for which the guard expression was satisfied.
private boolean	hasSatisfiedPrecondition	Indicates whether the precondition was satisfied for at least one row of the table.
private boolean	isEmpty	Indicates whether this table is empty.
private List<ExecutableBooleanExpression>	postConditions	The list of post-conditions whose guard expression was satisfied.

Constructor Summary

Constructors

Constructor	Description
ExpectedOutcomeTable()	Creates an empty ExpectedOutcomeTable.

Method Summary

Modifier and Type	Method	Description
(package private) void	add(boolean guardIsSatisfied, ExecutableBooleanExpression postcondition, List<ThrowsClause> throwsClauses)	Adds one operation to this table.
TestCheckGenerator	addPostCheckGenerator(TestCheckGenerator gen)	Constructs the TestCheckGenerator that will test for expected ThrowsClauses or postconditions as follows: If this table is empty, returns the given generator.
boolean	isInvalidCall()	Indicate whether the call should be classified as GenInputsAbstract.BehaviorType.INVALID.)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

isEmpty

private boolean isEmpty

Indicates whether this table is empty.

hasSatisfiedPrecondition

private boolean hasSatisfiedPrecondition

Indicates whether the precondition was satisfied for at least one row of the table.

postConditions

private final List<ExecutableBooleanExpression> postConditions

The list of post-conditions whose guard expression was satisfied.

exceptionSets

private final List<List<ThrowsClause>> exceptionSets

The list of lists of throws clauses for which the guard expression was satisfied. Each list of throwsclauses represents one specification, and each such list must be satisfied.

Constructor Detail

ExpectedOutcomeTable

public ExpectedOutcomeTable()

Creates an empty ExpectedOutcomeTable.

Method Detail

add

void add(boolean guardIsSatisfied,
         ExecutableBooleanExpression postcondition,
         List<ThrowsClause> throwsClauses)

Adds one operation to this table.

Parameters:

guardIsSatisfied - boolean value indicating whether all guard expressions are satisfied

postcondition - property expression that must be true in post-state if no exception is thrown

throwsClauses - set of <exception type, comment> pairs for exceptions expected in post-state

isInvalidCall

public boolean isInvalidCall()

Indicate whether the call should be classified as GenInputsAbstract.BehaviorType.INVALID.)

Occurs when all guard expressions fail and there are no expected exceptions.

This method should be called after all entries are added; that is, no more entries should be added after it is called.

Returns:

true iff guard expressions of all specifications are unsatisfied, and there are no expected exceptions

addPostCheckGenerator

public TestCheckGenerator addPostCheckGenerator(TestCheckGenerator gen)

Constructs the TestCheckGenerator that will test for expected ThrowsClauses or postconditions as follows:

• If this table is empty, returns the given generator.
• If this table has expected exceptions, then returns a ExpectedExceptionGenerator to check for those exceptions.
• If all preconditions fail, then return an InvalidCheckGenerator.
• if any GuardPropertyPair has a satisfied guard expression, then extend the given generator with a PostConditionCheckGenerator.

Parameters:

gen - the generator to extend

Returns:

the TestCheckGenerator to check for expected outcomes in this table

toString

public String toString()

Overrides:

toString in class Object