Sample demo of an Integration test

SendTransactionsFragmentTest.kt

package com.changui.penguinpay

import android.os.SystemClock.sleep
import androidx.arch.core.executor.testing.InstantTaskExecutorRule
import androidx.test.espresso.Espresso.onData
import androidx.test.espresso.Espresso.onView
import androidx.test.espresso.IdlingRegistry
import androidx.test.espresso.action.ViewActions.*
import androidx.test.espresso.assertion.ViewAssertions.matches
import androidx.test.espresso.matcher.ViewMatchers.*
import androidx.test.ext.junit.rules.activityScenarioRule
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.LargeTest
import androidx.test.rule.GrantPermissionRule
import com.jakewharton.espresso.OkHttp3IdlingResource
import okhttp3.OkHttpClient
import okhttp3.mockwebserver.Dispatcher
import okhttp3.mockwebserver.MockResponse
import okhttp3.mockwebserver.MockWebServer
import okhttp3.mockwebserver.RecordedRequest
import org.hamcrest.Matchers.allOf
import org.hamcrest.core.Is.`is`
import org.hamcrest.core.IsInstanceOf.instanceOf
import org.hamcrest.core.StringContains.containsString
import org.junit.After
import org.junit.Rule
import org.junit.Test
import org.junit.rules.TestRule
import org.junit.runner.RunWith
import org.koin.test.KoinTest

@LargeTest
@RunWith(AndroidJUnit4::class)
class SendTransactionsFlowTest: KoinTest {

    @get:Rule
    val activityTestRule = activityScenarioRule<MainActivity>()

    @get:Rule
    var rule: TestRule = InstantTaskExecutorRule()

    @get:Rule
    var permissionRule: GrantPermissionRule = GrantPermissionRule.grant(
        android.Manifest.permission.INTERNET,
        android.Manifest.permission.ACCESS_NETWORK_STATE,
    )

    val mockWebServer: MockWebServer = MockWebServer()


    @Test
    fun verify_displaying_screen_to_send_a_transaction_all_user_interactions_are_made() {
        mockWebServer.dispatcher = object : Dispatcher() {
            override fun dispatch(request: RecordedRequest): MockResponse {
                return when(request.path) {
                    "/latest.json?app_id=appId" -> "api.json".mockResponsePathOK()
                    else -> MockResponse().setResponseCode(404)
                }
            }
        }
        mockWebServer.start()
        val idlingResource = OkHttp3IdlingResource.create("okhttp", OkHttpClient.Builder().build())
        IdlingRegistry.getInstance().register(idlingResource)

        onView(withResourceName("recipient_phone_number")).check(matches(isDisplayed()))
        onView(withText("You're sending money to")).check(matches(isDisplayed()))
        onView(allOf(withResourceName("user_name"), withHint(R.string.hint_firstname_lastname))).check(matches(isDisplayed()))
        onView(withResourceName("user_name")).perform(typeText("claude hangui"), closeSoftKeyboard())
        sleep(60)
        onView(withResourceName("spinner")).perform(click())
        onData(allOf(`is`(instanceOf(String::class.java)), `is`("Nigeria"))).perform(click())
        onView(withResourceName("country_phone_prefix")).check(matches(withText("234")))
        onView(withResourceName("phone_digit_count")).check(matches(withText((containsString("7")))))
        onView(withResourceName("phone_digit_count")).check(matches(isDisplayed()))
        onView(withResourceName("receiver_currency")).check(matches(withText("NGN")))
        onView(withResourceName("conversion_rate")).check(matches(isEnabled()))
        sleep(60)

        onView(withResourceName("conversion_rate")).check(matches(withText((containsString("NGN")))))
        onView(withResourceName("recipient_phone_number")).perform(typeText("7654321"), closeSoftKeyboard())
        sleep(60)
        onView(withResourceName("amount_sent")).perform(typeText("11"), closeSoftKeyboard())
        onView(withResourceName("amount_received")).check(matches(withText((containsString("10011")))))
        
        IdlingRegistry.getInstance().unregister(idlingResource)
    }

    fun String.mockResponsePathOK(code: Int = 200): MockResponse {
        return MockResponse().setResponseCode(code).setBody(ResourceReaderUtils.loadJsonResource(this))
    }

    @After
    fun tearDown() {
        mockWebServer.shutdown()
    }


}