flink-libraries/flink-cep/src/test/java/org/apache/flink/cep/nfa/UntilConditionITCase.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.cep.nfa;

import org.apache.flink.cep.Event;
import org.apache.flink.cep.pattern.Pattern;
import org.apache.flink.cep.pattern.conditions.IterativeCondition;
import org.apache.flink.cep.pattern.conditions.SimpleCondition;
import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;

import org.apache.flink.shaded.guava18.com.google.common.collect.Lists;

import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

import static org.apache.flink.cep.nfa.NFATestUtilities.compareMaps;
import static org.apache.flink.cep.nfa.NFATestUtilities.feedNFA;
import static org.apache.flink.cep.utils.NFAUtils.compile;
import static org.junit.Assert.assertEquals;

/**
 * Tests for {@link Pattern#until(IterativeCondition)}.
 */
public class UntilConditionITCase {


	/**
	 * Condition used for {@link Pattern#until(IterativeCondition)} clause.
	 */
	public static final SimpleCondition<Event> UNTIL_CONDITION = new SimpleCondition<Event>() {
		private static final long serialVersionUID = 5726188262756267490L;

		@Override
		public boolean filter(Event value) throws Exception {
			return value.getPrice() == 5.0;
		}
	};

	@Test
	public void testUntilConditionFollowedByOneOrMore() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event breaking = new Event(44, "a", 5.0);
		Event ignored = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(ignored, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().until(UNTIL_CONDITION)
			.followedBy("end").where(
				UNTIL_CONDITION
			);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, breaking),
			Lists.newArrayList(startEvent, middleEvent1, breaking)
		));

		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testUntilConditionFollowedByOneOrMoreCombinations() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event middleEvent3 = new Event(43, "a", 4.0);
		Event breaking = new Event(44, "a", 5.0);
		Event ignored = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(middleEvent3, 5));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(ignored, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().allowCombinations().until(UNTIL_CONDITION)
			.followedBy("end").where(UNTIL_CONDITION);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, middleEvent3, breaking),
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, breaking),
			Lists.newArrayList(startEvent, middleEvent1, middleEvent3, breaking),
			Lists.newArrayList(startEvent, middleEvent1, breaking)
		));
		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testUntilConditionFollowedByOneOrMoreConsecutive() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event breaking = new Event(45, "a", 5.0);
		Event ignored = new Event(46, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(breaking, 7));
		inputEvents.add(new StreamRecord<>(ignored, 8));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().consecutive().until(UNTIL_CONDITION)
			.followedBy("end").where(
				UNTIL_CONDITION
			);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, breaking),
			Lists.newArrayList(startEvent, middleEvent1, breaking)
		));
		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testUntilConditionFollowedByOneOrMoreConsecutive2() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "b", 3.0);
		Event middleEvent3 = new Event(43, "a", 4.0);
		Event breaking = new Event(45, "a", 5.0);
		Event ignored = new Event(46, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(middleEvent3, 5));
		inputEvents.add(new StreamRecord<>(breaking, 7));
		inputEvents.add(new StreamRecord<>(ignored, 8));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().consecutive().until(UNTIL_CONDITION)
			.followedBy("end").where(
				UNTIL_CONDITION
			);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, breaking)
		));
		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testUntilConditionFollowedByZeroOrMore() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event breaking = new Event(44, "a", 5.0);
		Event ignored = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(ignored, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().optional().until(UNTIL_CONDITION)
			.followedBy("end").where(
				UNTIL_CONDITION
			);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, breaking),
			Lists.newArrayList(startEvent, middleEvent1, breaking),
			Lists.newArrayList(startEvent, breaking)
		));
		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testUntilConditionFollowedByZeroOrMoreCombinations() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event middleEvent3 = new Event(43, "a", 4.0);
		Event breaking = new Event(44, "a", 5.0);
		Event ignored = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(middleEvent3, 5));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(ignored, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().optional().allowCombinations().until(UNTIL_CONDITION)
			.followedBy("end").where(UNTIL_CONDITION);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, middleEvent3, breaking),
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, breaking),
			Lists.newArrayList(startEvent, middleEvent1, middleEvent3, breaking),
			Lists.newArrayList(startEvent, middleEvent1, breaking),
			Lists.newArrayList(startEvent, breaking)
		));
		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testUntilConditionFollowedByZeroOrMoreConsecutive() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event breaking = new Event(45, "a", 5.0);
		Event ignored = new Event(46, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(breaking, 7));
		inputEvents.add(new StreamRecord<>(ignored, 8));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().optional().consecutive().until(UNTIL_CONDITION)
			.followedBy("end").where(
				UNTIL_CONDITION
			);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, breaking),
			Lists.newArrayList(startEvent, middleEvent1, breaking),
			Lists.newArrayList(startEvent, breaking)
		));
		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testUntilConditionFollowedByAnyOneOrMore() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event breaking = new Event(44, "a", 5.0);
		Event middleEvent3 = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(middleEvent3, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedByAny("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().until(UNTIL_CONDITION);

		NFA<Event> nfa = compile(pattern, false);

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2),
			Lists.newArrayList(startEvent, middleEvent1),
			Lists.newArrayList(startEvent, middleEvent2),
			Lists.newArrayList(startEvent, middleEvent3)
		));
	}

	@Test
	public void testUntilConditionFollowedByAnyZeroOrMore() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event breaking = new Event(44, "a", 5.0);
		Event middleEvent3 = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(middleEvent3, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedByAny("middle").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("a");
			}
		}).oneOrMore().optional().until(UNTIL_CONDITION);

		NFA<Event> nfa = compile(pattern, false);

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2),
			Lists.newArrayList(startEvent, middleEvent1),
			Lists.newArrayList(startEvent, middleEvent2),
			Lists.newArrayList(startEvent, middleEvent3),
			Lists.newArrayList(startEvent)
		));
	}

	@Test
	public void testUntilConditionWithEmptyWhere() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event middleEvent3 = new Event(40, "d", 1.0);
		Event breaking = new Event(44, "a", 5.0);
		Event ignored = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(middleEvent3, 5));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(ignored, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").oneOrMore().until(UNTIL_CONDITION);

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, middleEvent3),
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2),
			Lists.newArrayList(startEvent, middleEvent1)
		));

		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testIterativeUntilConditionOneOrMore() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event middleEvent3 = new Event(40, "d", 1.0);
		Event breaking = new Event(44, "a", 5.0);
		Event ignored = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(middleEvent3, 5));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(ignored, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").oneOrMore().until(new IterativeCondition<Event>() {
			@Override
			public boolean filter(Event value, Context<Event> ctx) throws Exception {

				double sum = 0;
				for (Event middle : ctx.getEventsForPattern("middle")) {
					sum += middle.getPrice();
				}

				return sum == 6.0;
			}
		});

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, middleEvent3),
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2),
			Lists.newArrayList(startEvent, middleEvent1)
		));

		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}

	@Test
	public void testIterativeUntilConditionZeroOrMore() throws Exception {
		List<StreamRecord<Event>> inputEvents = new ArrayList<>();

		Event startEvent = new Event(40, "c", 1.0);
		Event middleEvent1 = new Event(41, "a", 2.0);
		Event middleEvent2 = new Event(42, "a", 3.0);
		Event middleEvent3 = new Event(40, "d", 1.0);
		Event breaking = new Event(44, "a", 5.0);
		Event ignored = new Event(45, "a", 6.0);

		inputEvents.add(new StreamRecord<>(startEvent, 1));
		inputEvents.add(new StreamRecord<>(middleEvent1, 3));
		inputEvents.add(new StreamRecord<>(middleEvent2, 4));
		inputEvents.add(new StreamRecord<>(middleEvent3, 5));
		inputEvents.add(new StreamRecord<>(breaking, 6));
		inputEvents.add(new StreamRecord<>(ignored, 7));

		Pattern<Event, ?> pattern = Pattern.<Event>begin("start").where(new SimpleCondition<Event>() {
			private static final long serialVersionUID = 5726188262756267490L;

			@Override
			public boolean filter(Event value) throws Exception {
				return value.getName().equals("c");
			}
		}).followedBy("middle").oneOrMore().optional().until(new IterativeCondition<Event>() {
			@Override
			public boolean filter(Event value, Context<Event> ctx) throws Exception {

				double sum = 0;
				for (Event middle : ctx.getEventsForPattern("middle")) {
					sum += middle.getPrice();
				}

				return sum == 6.0;
			}
		});

		NFA<Event> nfa = compile(pattern, false);

		NFAState nfaState = nfa.createInitialNFAState();

		final List<List<Event>> resultingPatterns = feedNFA(inputEvents, nfa, nfaState);

		compareMaps(resultingPatterns, Lists.<List<Event>>newArrayList(
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2, middleEvent3),
			Lists.newArrayList(startEvent, middleEvent1, middleEvent2),
			Lists.newArrayList(startEvent, middleEvent1),
			Lists.newArrayList(startEvent)
		));

		assertEquals(1, nfaState.getPartialMatches().size());
		assertEquals("start", nfaState.getPartialMatches().peek().getCurrentStateName());
	}
}