Groovy example source code file (CovariantReturnTest.groovy)

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Java - Groovy tags/keywords

a, arraylist, b, base, base, baseclass, baseclass, child, child, derivedclass, groovychildimpl, groovychildimpl, list, string

The Groovy CovariantReturnTest.groovy source code

/*
 * Copyright 2003-2010 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 CovariantReturnTest extends CompilableTestSupport {

    void testCovariantReturn() {
        assertScript """
            class A {
                Object foo() {1}
            }
            class B extends A{
                String foo(){"2"}
            }
            def b = new B();
            assert b.foo()=="2"
            assert B.declaredMethods.findAll{it.name=="foo"}.size()==2
        """
    }

    void testCovariantReturnOverwritingAbstractMethod() {
        assertScript """
            abstract class Numeric {
                abstract Numeric eval();
            }
            class Rational extends Numeric {
                Rational eval() {this}
            }
            assert Rational.declaredMethods.findAll{it.name=="eval"}.size()==2
        """
    }

    void testCovariantReturnOverwritingObjectMethod() {
        shouldNotCompile """
            class X {
                Long toString() { 333L }
                String hashCode() { "hash" }
            }
        """
    }

    void testCovariantOverwritingMethodWithPrimitives() {
        assertScript """
            class Base {
                Object foo(boolean i) {i}
            }
            class Child extends Base {
                String foo(boolean i) {""+super.foo(i)}
            }
            def x = new Child()
            assert x.foo(true) == "true"
            assert x.foo(false) == "false"
        """
    }

    void testCovariantOverwritingMethodWithInterface() {
        assertScript """
            interface Base {
                List foo()
                Base baz()
            }
            interface Child extends Base {
                ArrayList foo()
                Child baz()
            }
            class GroovyChildImpl implements Child {
                ArrayList foo() {}
                GroovyChildImpl baz() {}
            }
            def x = new GroovyChildImpl()
            x.foo()
            x.baz()
        """
    }

    void testCovariantOverwritingMethodWithInterfaceAndInheritance() {
        assertScript """
            interface Base {
                List foo()
                List bar()
            Base baz()
            }
            interface Child extends Base {
                ArrayList foo()
            }
            class MyArrayList extends ArrayList { }
            class GroovyChildImpl implements Child {
                MyArrayList foo() {}
                MyArrayList bar() {}
                GroovyChildImpl baz() {}
            }
            def x = new GroovyChildImpl()
            x.foo()
            x.bar()
            x.baz()
        """
    }

    void testCovariantMethodFromParentOverwritingMethodFromInterfaceInCurrentclass() {
        assertScript """
            interface I {
                def foo()
            }
            class A {
                String foo(){""}
            }
            class B extends A implements I{}
            def b = new B()
            assert b.foo() == ""
        """

        // basically the same as above, but with an example
        // from an error report (GROOVY-2582)
        // Properties has a method "String getProperty(String)", this class
        // is also a GroovyObject, meaning a "Object getProperty(String)" method
        // should be implemented. But this method should not be the usual automatically
        // added getProperty, but a bridge to the getProperty method provided by Properties
        assertScript """
            class Configuration extends java.util.Properties {}
            assert Configuration.declaredMethods.findAll{it.name=="getProperty"}.size() == 1
            def conf = new Configuration()
            conf.setProperty("a","b")
            // the following assert would fail if standard getProperty method was added
            // by the compiler
            assert conf.getProperty("a") == "b"
        """
    }

    void testImplementedInterfacesNotInfluencing() {
        // in GROOVY-3229 some methods from Appendable were not correctly recognized
        // as already being overriden (PrintWriter<Writer

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