ExpressionEvaluatorTest.java

package qlruntime;

import static nl.uva.sc.encoders.ql.ast.QuestionBuilder.aQuestion;
import static nl.uva.sc.encoders.ql.ast.TextLocationBuilder.aTextLocation;
import static org.hamcrest.CoreMatchers.instanceOf;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

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

import nl.uva.sc.encoders.ql.ast.expression.BinaryExpression;
import nl.uva.sc.encoders.ql.ast.expression.BracedExpression;
import nl.uva.sc.encoders.ql.ast.expression.Expression;
import nl.uva.sc.encoders.ql.ast.expression.LiteralExpression;
import nl.uva.sc.encoders.ql.ast.expression.NameExpression;
import nl.uva.sc.encoders.ql.ast.expression.UnaryExpression;
import nl.uva.sc.encoders.ql.ast.literal.BooleanLiteral;
import nl.uva.sc.encoders.ql.ast.literal.IntegerLiteral;
import nl.uva.sc.encoders.ql.ast.literal.StringLiteral;
import nl.uva.sc.encoders.ql.ast.operator.AddOperator;
import nl.uva.sc.encoders.ql.ast.operator.AndOperator;
import nl.uva.sc.encoders.ql.ast.operator.MultiplyOperator;
import nl.uva.sc.encoders.ql.ast.operator.NotOperator;
import nl.uva.sc.encoders.ql.ast.operator.OrOperator;
import nl.uva.sc.encoders.qlruntime.evaluator.ExpressionEvaluator;
import nl.uva.sc.encoders.qlruntime.model.RuntimeQuestion;
import nl.uva.sc.encoders.qlruntime.model.value.BooleanValue;
import nl.uva.sc.encoders.qlruntime.model.value.IntegerValue;
import nl.uva.sc.encoders.qlruntime.model.value.StringValue;
import nl.uva.sc.encoders.qlruntime.model.value.Value;

import org.junit.Test;

public class ExpressionEvaluatorTest {

	/**
	 * Testing (3 + 7) * 8 = 80
	 */
	@Test
	public void testEvaluatesIntegerExpressions() {
		List<RuntimeQuestion> questions = new ArrayList<>();

		ExpressionEvaluator evaluator = new ExpressionEvaluator(questions);

		LiteralExpression integerThree = new LiteralExpression(aTextLocation().build(), new IntegerLiteral(3));
		LiteralExpression integerSeven = new LiteralExpression(aTextLocation().build(), new IntegerLiteral(7));
		LiteralExpression integerEight = new LiteralExpression(aTextLocation().build(), new IntegerLiteral(8));
		BinaryExpression addExpression = new BinaryExpression(aTextLocation().build(), integerThree, integerSeven, new AddOperator(
				"+"));
		BracedExpression bracedExpression = new BracedExpression(aTextLocation().build(), addExpression);
		BinaryExpression multiplyExpression = new BinaryExpression(aTextLocation().build(), bracedExpression, integerEight,
				new MultiplyOperator("*"));

		Value result = multiplyExpression.accept(evaluator);

		assertThat(result, is(instanceOf(IntegerValue.class)));
		assertThat(((IntegerValue) result).getValue(), is(80));
	}

	/**
	 * Testing "Hi" + " there!" = "Hi there!"
	 */
	@Test
	public void testEvaluatesStringConcatenation() {
		List<RuntimeQuestion> questions = new ArrayList<>();

		ExpressionEvaluator evaluator = new ExpressionEvaluator(questions);

		Expression hiExpression = new LiteralExpression(aTextLocation().build(), new StringLiteral("Hi"));
		Expression thereExpression = new LiteralExpression(aTextLocation().build(), new StringLiteral(" there!"));
		BinaryExpression multiplyExpression = new BinaryExpression(aTextLocation().build(), hiExpression, thereExpression,
				new AddOperator("+"));

		Value result = multiplyExpression.accept(evaluator);

		assertThat(result, is(instanceOf(StringValue.class)));
		assertThat(((StringValue) result).getValue(), is("Hi there!"));
	}

	/**
	 * Testing (true || false) && !false = true
	 */
	@Test
	public void testEvaluatesBooleanExpressions() {
		List<RuntimeQuestion> questions = new ArrayList<>();

		ExpressionEvaluator evaluator = new ExpressionEvaluator(questions);

		LiteralExpression trueExpression = new LiteralExpression(aTextLocation().build(), new BooleanLiteral(true));
		LiteralExpression falseExpression = new LiteralExpression(aTextLocation().build(), new BooleanLiteral(false));

		BinaryExpression orExpression = new BinaryExpression(aTextLocation().build(), trueExpression, falseExpression,
				new OrOperator("||"));
		BracedExpression bracedExpression = new BracedExpression(aTextLocation().build(), orExpression);
		Expression notExpression = new UnaryExpression(aTextLocation().build(), new NotOperator("!"), falseExpression);
		BinaryExpression andExpression = new BinaryExpression(aTextLocation().build(), bracedExpression, notExpression,
				new AndOperator("&&"));

		Value result = andExpression.accept(evaluator);

		assertThat(result, is(instanceOf(BooleanValue.class)));
		assertThat(((BooleanValue) result).getValue(), is(true));
	}

	/**
	 * Testing someQuestionReference = true
	 */
	@Test
	public void testEvaluatesNamedExpressions() {
		String questionName = "someQuestionReference";
		List<RuntimeQuestion> questions = new ArrayList<>();
		BooleanValue value = new BooleanValue(true);
		RuntimeQuestion runtimeQuestion = new RuntimeQuestion(aQuestion().withName(questionName).build(), value);
		questions.add(runtimeQuestion);

		ExpressionEvaluator evaluator = new ExpressionEvaluator(questions);
		NameExpression nameExpression = new NameExpression(aTextLocation().build(), questionName);

		Value result = nameExpression.accept(evaluator);

		assertThat(result, is(value));
	}
}