import my.component.GleanMetrics.Pings
import my.component.GleanMetrics.CustomPingData

class MyCustomPingScheduler {
  /**
   * HERE ONLY TO KEEP THE EXAMPLE SIMPLE.
   *
   * A function that consumes the Glean SDK generated metrics API to
   * record some data. It doesn't really need to be in a function, nor
   * in this class. The Glean SDK API can be called when the data is
   * generated.
   */
  fun addSomeData() {
    // Record some sample data.
    CustomPingData.sampleString.set("test-data")
  }

  /**
   * Called to implement the ping scheduling logic for 'my_custom_ping'.
   */
  fun schedulePing() {
    // ... some scheduling logic that will end up calling the function below.
    submitPing()
  }

  /**
   * Internal function to only be overridden in tests. This
   * calls the Glean SDK API to send custom pings.
   */
  @VisibleForTesting(otherwise = VisibleForTesting.NONE)
  internal fun submitPing() {
    Pings.MyCustomPing.submit()
  }
}

The following unit test intercepts the MyCustomPingScheduler.submitPing() call in order to perform the validation on the data. This specific example uses Mockito, but any other framework would work.

// Metrics and pings definitions.
import my.component.GleanMetrics.Pings
import my.component.GleanMetrics.CustomPingData

// Mockito imports for using spies.
import org.mockito.Mockito.spy
import org.mockito.Mockito.`when`

@RunWith(AndroidJUnit4::class)
class MyCustomPingSchedulerTest {
    // Apply the GleanTestRule to set up a disposable Glean instance.
    // Please note that this clears the Glean data across tests.
    @get:Rule
    val gleanRule = GleanTestRule(ApplicationProvider.getApplicationContext())

    @Test
    fun `verify custom ping metrics`() {
      val scheduler = spy(MyCustomPingScheduler())
      doAnswer {
        // Here we validate the content that goes into the ping.
        assertTrue(CustomPingData.sampleString.testHasValue())
        assertEquals("test-data", CustomPingData.sampleString.testGetValue())

        // We want to intercept this call, but we also want to make sure the
        // real Glean API is called in order to clear the ping store and to provide
        // consistent behaviour with respect to the application.
        it.callRealMethod()
      }.`when`(scheduler).submitPing()

      scheduler.addSomeData()
      scheduler.schedulePing()
    }
}

import Foundation
import Glean

// Use typealiases to simplify usage.
// This can be placed anywhere in your code to be available in all files.
typealias CustomPingData = GleanMetrics.CustomPingData
typealias Pings = GleanMetrics.Pings

class MyCustomPingScheduler {
    /**
     * HERE ONLY TO KEEP THE EXAMPLE SIMPLE.
     *
     * A function that consumes the Glean SDK generated metrics API to
     * record some data. It doesn't really need to be in a function, nor
     * in this class. The Glean SDK API can be called when the data is
     * generated.
     */
    func addSomeData() {
       // Record some sample data.
       CustomPingData.sampleString.set("test-data")
    }

    /**
     * Called to implement the ping scheduling logic for 'my_custom_ping'.
     */
    func schedulePing() {
        // ... some scheduling logic that will end up calling the function below.
        submitPing()
    }

    /**
     * Internal function to only be overridden in tests. This
     * calls the Glean SDK API to send custom pings.
     */
    internal func submitPing() {
        Pings.shared.myCustomPing.submit()
    }
}

The following unit test intercepts the MyCustomPingScheduler.submitPing() call in order to perform the validation on the data. This example uses a manual mock implementation, but you could use a framework for that.

@testable import YourApplication
import Glean
import XCTest

class MyCustomPingSchedulerMock: MyCustomPingScheduler {
    var submitWasCalled = false

    deinit {
        XCTAssertTrue(submitWasCalled, "submitPing should have been called once")
    }

    override func submitPing() {
        submitWasCalled = true

        XCTAssertTrue(CustomPingData.os.testHasValue())
        XCTAssertEqual("test-data", try! CustomPingData.os.testGetValue())

        super.submitPing()
    }
}

class MyCustomPingSchedulerTests: XCTestCase {
    override func setUp() {
        Glean.shared.resetGlean(clearStores: true)
    }

    func testCustomPingMetrics() {
        let scheduler = MyCustomPingSchedulerMock()
        scheduler.addSomeData()
        scheduler.schedulePing()
    }
}

import glean

metrics = glean.load_metrics("metrics.yaml")
pings = glean.load_pings("pings.yaml")


class MyCustomPingScheduler:
    def add_some_data(self):
        """
        HERE ONLY TO KEEP THE EXAMPLE SIMPLE.

        A function that consumes the Glean SDK generated metrics API to
        record some data. It doesn't really need to be in a function, nor
        in this class. The Glean SDK API can be called when the data is
        generated.
        """
        # Record some sample data.
        metrics.custom_ping_data.sample_string.set("test-data")

    def schedule_ping(self):
        """
        Called to implement the ping scheduling logic for 'my_custom_ping'.
        """
        # ... some scheduling logic that will end up calling the function below.
        self._submit_ping()

    def _submit_ping(self):
        """
        Internal function to only be overridden in tests.
        """
        pings.my_custom_ping.submit()

The following unit test intercepts the MyCustomPingScheduler._submit_ping() call in order to perform the validation on the data.

from unittest.mock import MagicMock

from glean import testing

import custom_ping_scheduler


# This will be run before every test in the entire test suite
def pytest_runtest_setup(item):
    testing.reset_glean(application_id="my-app", application_version="0.0.1")


def test_verify_custom_ping_metrics():
    scheduler = custom_ping_scheduler.MyCustomPingScheduler()

    original_submit_ping = scheduler._submit_ping

    def _submit_ping(self):
        # Here we validate the content that goes into the ping.
        assert (
            custom_ping_scheduler.metrics.custom_ping_data.sample_string.test_has_value()
        )
        assert (
            "test-data"
            == custom_ping_scheduler.metrics.custom_ping_data.sample_string.test_get_value()
        )

        # We want to intercept this call, but we also want to make sure the
        # real Glean API is called in order to clear the ping strong and to
        # provide consistent behavior with respect to the application.
        original_submit_ping(self)

    scheduler._submit_ping = MagicMock(_submit_ping)

    scheduler.add_some_data()
    scheduler.schedule_ping()

TODO. To be implemented in bug 1648446.