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Groovy example source code file (MethodSelectionTest.groovy)

This example Groovy source code file (MethodSelectionTest.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

a, a, b, biginteger, c, c, d, e, i1, i1, i2, i2, missingmethodexception, super

The Groovy MethodSelectionTest.groovy source code

/*
 * Copyright 2003-2009 the original author or authors.
 *
 * Licensed 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 gls.invocation

import gls.CompilableTestSupport

public class MethodSelectionTest extends CompilableTestSupport {

  /**
   * This test ensures Groovy can choose a method based on interfaces.
   * Choosing such an interface should not be hidden by subclasses.
   */
  public void testMostSpecificInterface() {
    assertScript """
      interface A{}
      interface B extends A{}
      class C implements B,A{}
      class D extends C{}
      class E implements B{}

      def m(A a){1}
      def m(B b){2}

      assert m(new D()) == 2
      assert m(new C()) == 2
      assert m(new E()) == 2
    """   
    
    assertScript """
      class A implements I1 {}
      class B extends A implements I2 {}
      class C extends B implements I3 {}
      interface I1 {}
      interface I2 extends I1 {}
      interface I3 extends I2 {}

      def foo(bar) {0}
      def foo(I1 bar) {1}
      def foo(I2 bar) {2}
      def foo(I3 bar) {3}

      assert foo(new A())==1
      assert foo(new B())==2
      assert foo(new C())==3
    """
  }
  
  public void testMostGeneralForNull() {
    // we use the same signatures with different method orders,
    // because we want to catch method ordering bugs
    assertScript """
      def m(String x){1}
      def m(Integer x){2}
      assert m(null) == 1
      
      def n(Integer x){2}
      def n(String x){1}
      assert n(null) == 1
    """
  }
  
  void testMethodSelectionException() {
    assertScript """
      import org.codehaus.groovy.runtime.metaclass.MethodSelectionException as MSE
    
      def foo(int x) {}
      def foo(Number x) {}
      
      try {
        foo()
        assert false
      } catch (MSE mse) {
        assert mse.message.indexOf("foo()") >0
        assert mse.message.indexOf("#foo(int)") >0
        assert mse.message.indexOf("#foo(java.lang.Number)") >0
      }
    
    """  
  }

  void testMethodSelectionWithInterfaceVargsMethod() {
    // GROOVY-2719
    assertScript """
      public class Thing {}
      public class Subthing extends Thing {}

      def foo(Thing i) {1}
      def foo(Runnable[] l) {2}

      assert foo(new Subthing())==1
    """
  }

  void testComplexInterfaceInheritance() {
    // GROOVY-2698
    assertScript """
        import javax.swing.*

        interface ISub extends Action {}

        class Super extends AbstractAction {
        void actionPerformed(java.awt.event.ActionEvent e){}
        }
        class Sub extends AbstractAction implements ISub {
        void actionPerformed(java.awt.event.ActionEvent e){}
        }

        static String foo(Action x) { "super" }
        static String foo(ISub x) { "sub" }

        def result = [new Super(), new Sub()].collect { foo(it) }

        assert ["super","sub"] == result
    """
  }
  
  void testNullUsageForPrimtivesWithExplcitNull() {
    [byte,int,short,float,double,boolean,char].each { type ->
      assertScript """
         def foo($type x) {}
         
         boolean catched = false
         try {
           foo(null)
         } catch (MissingMethodException mme) {
           catched = true
         }
         def txt = "expected to see a MissingMethodEception when using foo(null) "+
                   "to call foo($type), but no exception was thrown"
         assert catched, txt
      """
    }
  }
  
  void testNullUsageForPrimtivesWithImplcitNull() {
    [byte,int,short,float,double,boolean,char].each { type ->
      assertScript """
         def foo($type x) {}
         
         boolean catched = false
         try {
           foo()
         } catch (MissingMethodException mme) {
           catched = true
         }
         def txt = "expected to see a MissingMethodEception when using foo(null) "+
                   "to call foo($type), but no exception was thrown"
         assert catched, txt
      """
    }
  }
  
  void testNullUsageForPrimitivesAndOverloading() {
    [byte,int,short,float,double].each { type ->
      assertScript """
         def foo(String x){1}
         def foo($type x) {2}
         
         def txt = "foo($type) was called where foo(String) should have been called"
         assert foo(null)==1, txt
      """
    } 
  }
  
  void testPrivateMethodSelectionFromClosure(){
      assertScript """
          class I1 {
              private foo() {1}
              def bar(){
                def x = "foo"
                return {this."\$x"()}
              }
          }
          class I2 extends I1 {
              def foo(){2}
          }
          def i = new I2()
          assert i.bar()() == 1
      
      """
  }
  
  void testBDandBIToFloatAutoConversionInMethodSelection() {
    def foo = new Foo3977()
    
    // double examples were working already but float ones were not
    // adding both here just to make sure the inconsistency doesn't creep in again
    foo.setMyDouble1 1.0
    assert foo.getMyDouble1() == 1.0
    
    foo.setMyDouble1 new BigInteger('1')
    assert foo.getMyDouble1() == 1.0

    foo.setMyDouble2 1.0
    assert foo.getMyDouble2() == 1.0
    
    foo.setMyDouble2 new BigInteger('1')
    assert foo.getMyDouble2() == 1.0

    foo.setMyFloat1 1.0
    assert foo.getMyFloat1() == 1.0
    
    foo.setMyFloat1 new BigInteger('1')
    assert foo.getMyFloat1() == 1.0

    foo.setMyFloat2 1.0
    assert foo.getMyFloat2() == 1.0
    
    foo.setMyFloat2 new BigInteger('1')
    assert foo.getMyFloat2() == 1.0
  }
}

class Foo3977 {
    double myDouble1
    Double myDouble2
    float myFloat1
    Float myFloat2
}

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