[rules-dev] writing unit tests
It's great when people attach unit tests to jiras, it would be ever
better if they are just cut nad paste single files, rather than entire
projects, which take more time for us to fiddle with. Also please do try
and pair your actual program "main" examples down to minimal unit tests
of the actual problem. If you suspect the problem is MVEL, then please
do a minimal MVEL test, without Drools.
Put static classes in the same file, put rules in a concatenated string.
This means testing is as easy as cut and paste for us, and it can be
easily added to existing test classes. For example, from MiscTest.
public static class A {
private String field1;
private String field2;
public A(String field1,
String field2) {
this.field1 = field1;
this.field2 = field2;
}
public String getField1() {
return field1;
}
public void setField1( String field1 ) {
this.field1 = field1;
}
public String getField2() {
return field2;
}
public void setField2( String field2 ) {
this.field2 = field2;
}
public String toString() {
return "A) " + field1 + ":" + field2;
}
}
@Test
public void testExistsIterativeModifyBug() {
// JBRULES-2809
// This bug occurs when a tuple is modified, the remove/add
puts it onto the memory end
// However before this was done it would attempt to find the
next tuple, starting from itself
// This meant it would just re-add itself as the blocker, but
then be moved to end of the memory
// If this tuple was then removed or changed, the blocked was
unable to check previous tuples.
String str = "";
str += "package org.simple \n";
str += "import " + A.class.getCanonicalName() + "\n";
str += "global java.util.List list \n";
str += "rule xxx \n";
str += "when \n";
str += " $f1 : A() \n";
str += " exists A(this != $f1, eval(field2 ==
$f1.getField2())) \n";
str += " eval( !$f1.getField1().equals(\"1\") ) \n";
str += "then \n";
str += " list.add($f1); \n";
str += "end \n";
KnowledgeBase kbase = loadKnowledgeBaseFromString( str );
StatefulKnowledgeSession ksession =
kbase.newStatefulKnowledgeSession();
List list = new ArrayList();
ksession.setGlobal( "list",
list );
A a1 = new A( "2",
"2" );
A a2 = new A( "1",
"2" );
A a3 = new A( "1",
"2" );
FactHandle fa1 = (FactHandle) ksession.insert( a1 );
FactHandle fa2 = (FactHandle) ksession.insert( a2 );
FactHandle fa3 = (FactHandle) ksession.insert( a3 );
// a2, a3 are blocked by a1
// modify a1, so that a1,a3 are now blocked by a2
a1.setField2( "1" ); // Do
ksession.update( fa1,
a1 );
a1.setField2( "2" ); // Undo
ksession.update( fa1,
a1 );
// modify a2, so that a1,a2 are now blocked by a3
a2.setField2( "1" ); // Do
ksession.update( fa2,
a2 );
a2.setField2( "2" ); // Undo
ksession.update( fa2,
a2 );
// modify a3 to cycle, so that it goes on the memory end, but
in a previous bug still blocked a1
ksession.update( fa3,
a3 );
a3.setField2( "1" ); // Do
ksession.update( fa3,
a3 );
ksession.fireAllRules();
assertEquals( 1,
list.size() ); // a2 should still be blocked by
a1, but bug from previous update hanging onto blocked
ksession.dispose();
}