Groovy example source code file (CodeVisitorSupportTest.groovy)

This example Groovy source code file (CodeVisitorSupportTest.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

blockstatement, blockstatement, booleanexpression, booleanexpression, catchstatement, catchstatement, emptystatement, groovyinterceptable, groovytestcase, ifstatement, ioexception, recordingcodevisitorsupport, recordingcodevisitorsupport, trycatchstatement

The Groovy CodeVisitorSupportTest.groovy source code

package org.codehaus.groovy.ast;


import org.codehaus.groovy.ast.builder.AstBuilder
import org.codehaus.groovy.ast.stmt.*
import org.codehaus.groovy.ast.expr.*
import org.codehaus.groovy.control.CompilePhase


/**
 * Tests the CodeVisitorSupport.
 *
 * @author Hamlet D'Arcy
 */

public class CodeVisitorSupportTest extends GroovyTestCase {

    public void testIfElse() {
        def ast = new AstBuilder().buildFromCode { if (true) { 1 } else  { 2 } }
        def visitor = new RecordingCodeVisitorSupport()
        visitor.visitBlockStatement(ast[0]) // first element is always BlockStatement

        assert visitor.history[0] == BlockStatement
        assert visitor.history[1] == IfStatement
        assert visitor.history[2] == BooleanExpression
        assert visitor.history[3] == BlockStatement
        assert visitor.history[4] == BlockStatement
        assert visitor.history.size == 5
    }

    public void testEmptyStatementsOnIfElse() {
        def ast = new AstBuilder().buildFromCode(CompilePhase.SEMANTIC_ANALYSIS, true, {
            if (true) { 1 }
        })
        def visitor = new RecordingCodeVisitorSupport()
        visitor.visitBlockStatement(ast[0]) // first element is always BlockStatement

        assert visitor.history[0] == BlockStatement
        assert visitor.history[1] == IfStatement
        assert visitor.history[2] == BooleanExpression
        assert visitor.history[3] == BlockStatement
        assert visitor.history[4] == EmptyStatement
        assert visitor.history.size == 5
    }

    public void testTryCatchFinally() {
        def ast = new AstBuilder().buildFromCode {
            def x
            try {
                x = 1
            } catch (IOException ei) {
                x = 2
            } finally {
                x = 4
            }
        }
        def visitor = new RecordingCodeVisitorSupport()
        visitor.visitBlockStatement(ast[0]) // first element is always BlockStatement

        assert visitor.history[0] == BlockStatement
        assert visitor.history[1] == TryCatchStatement
        assert visitor.history[2] == BlockStatement
        assert visitor.history[3] == CatchStatement
        assert visitor.history[4] == BlockStatement
    }

    public void testEmptyStatementsOnTryCatch() {
        def ast = new AstBuilder().buildFromCode {
            def x
            try {
                x = 1
            } catch (IOException ei) {
                x = 2
            }
        }
        def visitor = new RecordingCodeVisitorSupport()
        visitor.visitBlockStatement(ast[0]) // first element is always BlockStatement

        assert visitor.history[0] == BlockStatement
        assert visitor.history[1] == TryCatchStatement
        assert visitor.history[2] == BlockStatement
        assert visitor.history[3] == CatchStatement
        assert visitor.history[4] == BlockStatement
        assert visitor.history[5] == EmptyStatement
    }
}

/**
* Records the visit method that were called so that they can be queried and verified later.
* This would be better implemented using invokeMethod but it is called from Java so it
* won't dispatch correctly. 
*
* @author Hamlet D'Arcy
*/
private class RecordingCodeVisitorSupport extends CodeVisitorSupport implements GroovyInterceptable {
    def history = []

    public void visitBlockStatement(BlockStatement node) {
        history << node.getClass()
        super.visitBlockStatement(node)
    }

    public void visitIfElse(IfStatement node) {
        history << node.getClass()
        super.visitIfElse(node)
    }

    public void visitBooleanExpression(BooleanExpression node) {
        history << node.getClass()
        super.visitBooleanExpression(node)
    }

    protected void visitEmptyStatement(EmptyStatement node) {
        history << node.getClass()
        super.visitEmptyStatement(node)
    }

    public void visitTryCatchFinally(TryCatchStatement node) {
        history << node.getClass()
        super.visitTryCatchFinally(node);
    }

    public void visitCatchStatement(CatchStatement node) {
        history << node.getClass()
        super.visitCatchStatement(node);    
    }

}