The plugin is essentially moved from the `buildSrc` folder to its own build called `greeting-plugin`.

NOTE: You can publish the plugin from `buildSrc`, but this is not recommended practice. Plugins that are ready for publication should be in their own build.

`greeting-plugin` is simply a Java project that produces a JAR containing the plugin classes.

        debugInstall.exec().out == app.withFeatureDisabled().expectedOutput
        debugInstall.assertIncludesLibraries("greeting")
        def debugLib = sharedLibrary(producer.file("build/lib/main/debug/greeting"))
        sharedLibrary(consumer.file("build/install/main/debug/lib/greeting")).file.assertIsCopyOf(debugLib.file)

        when:
        executer.inDirectory(consumer)
        run("installRelease")

This Gradle build file defines a task `GreetingToFileTask` that writes a greeting to a file.
It also registers two tasks: `greet`, which creates the file with the greeting, and `sayGreeting`, which prints the file's contents.
The `greetingFile` property is used to specify the file path for the greeting:

====
include::sample[dir="snippets/tasks/customTaskWithFileProperty/kotlin",files="build.gradle.kts[tags=all]"]

	return code, msg, err
}

// helo sends the HELO greeting to the server. It should be used only when the
// server does not support ehlo.
func (c *Client) helo() error {
	c.ext = nil
	_, _, err := c.cmd(250, "HELO %s", c.localName)
	return err
}

// ehlo sends the EHLO (extended hello) greeting to the server. It
// should be the preferred greeting for servers that support it.
func (c *Client) ehlo() error {

        return "Hello World!";
    }

    public static void main(String[] args) {
        System.out.println(new App().getGreeting());
    }
}
----

The code prints out a simple "Hello World" greeting to the screen.

A test class is available at `app/src/test/java/authoring/tutorial/AppTest.java`:

.AppTest.java
[source, java]
----
package authoring.tutorial;

import org.junit.jupiter.api.Test;

                @Test
                public void testSomething() {
                    App classUnderTest = new App();
                    Assert.assertNotNull(classUnderTest.getGreeting(), "app should have a greeting");
                }
            }
        """

        expect: "compilation does not configure tests"
        succeeds("compileJava")

        and: "running tests fails due to configuring tests"

                @Input
                abstract Property<String> getGreeting()

                @TaskAction void run() { println greeting.get() }
            }

            def greetValueSource = providers.of(GreetValueSource) {}
            tasks.register("greet", MyTask) {
                greeting = greetValueSource
            }
        """)

        when:
        configurationCacheRun "greet"

        then:

		t.Error(evt)
	}
}

// api

const greeting = "hello, world"

type testPair struct {
	Name      string
	Got, Want interface{}
}

var testPairs = []testPair{
	{"GoString", C.GoString(C.greeting), greeting},
	{"GoStringN", C.GoStringN(C.greeting, 5), greeting[:5]},
	{"GoBytes", C.GoBytes(unsafe.Pointer(C.greeting), 5), []byte(greeting[:5])},
}

func testHelpers(t *testing.T) {

            applicationDefaultJvmArgs = ["-Dgreeting.language=en", "-DappId=\${project.name - ':'}"]
        }
        """

        when:
        succeeds('startScripts')

        then:
        assertGeneratedUnixStartScript('myApp').text.contains '-Dgreeting.language=en'
        assertGeneratedWindowsStartScript('myApp').text.contains '-Dgreeting.language=en'
    }

.Output of **`gradle greeting`**
----
> gradle greeting
include::{snippetsPath}/mavenMigration/profiles/tests/greeting-default.out[]
----
.Output of **`gradle -PbuildProfile=test greeting`**
----
> gradle -PbuildProfile=test greeting
include::{snippetsPath}/mavenMigration/profiles/tests/greeting-test.out[]
----

You're not limited to checking project properties.