单元测试 WebView 的 WebViewClient 回调的 onPageStarted 和 onPageFinished

Question

Android Studio 3.5.1
Kotlin 1.3

我尝试对以下方法进行单元测试。使用 WebView 和 WebViewClient

我的方法如下，需要进行单元测试：

fun setPageStatus(webView: WebView?, pageStatus: (PageStatusResult) -> Unit) {
    webView?.webViewClient = object : WebViewClient() {

        override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
            pageStatus(PageStatusResult.PageStarted(url ?: "", favicon))
        }

        override fun onPageFinished(view: WebView?, url: String?) {
            pageStatus(PageStatusResult.PageFinished(url ?: ""))
        }
    }
}

我使用了一个 webView，它覆盖了来自 WebViewClient 的一些回调。然后在 onPageStarted 或 onPageFinished 中调用一个 lambda 函数。

使用密封 class 设置在 lambda 方法中传递的属性

sealed class PageStatusResult {
    data class PageFinished(val url: String) : PageStatusResult()
    data class PageStarted(val url: String, val favicon: Bitmap?) : PageStatusResult()
}

在单元测试中我做了这样的事情：

@Test
fun `should set the correct settings of the WebView`() {
    // Arrange the webView
    val webView = WebView(RuntimeEnvironment.application.baseContext)

    // Act by calling the setPageStatus
    webFragment.setPageStatus(webView) { pageStatusResult ->
        when(pageStatusResult) {
            is PageStarted -> {
            // Assert that the url is correct
                assertThat(pageStatusResult.url).isEqualToIgnoringCase("http://google.com")
            }
        }
    }

    // Call the onPageStarted on the webViewClient and and assert in the when statement
    webView.webViewClient.onPageStarted(webView, "http://google.com", null)
}

Answer 1

由于此单元测试的性质是异步的，因此您应该使用异步测试方法，而不是自己同步调用 webView.webViewClient.onPageStarted。这样，我们传一个URL给WebView来显示，然后等onPageStarted方法被WebView自己调用。

运行 Android 中异步单元测试的最佳选择似乎是使用 Awaitility。

build.gradle

dependencies {
    testImplementation 'org.awaitility:awaitility:4.0.1'
}

单元测试Class

@Test
fun `should set the correct settings of the WebView`() {

    val requestedUrl = "https://www.google.com"
    var resultUrl: String? = null

    // Arrange the webView
    val webView = WebView(RuntimeEnvironment.application.baseContext)

    // Act by calling the setPageStatus
    webFragment.setPageStatus(webView) { pageStatusResult ->
        when (pageStatusResult) {
            is PageStatusResult.PageStarted -> {
                resultUrl = pageStatusResult.url
            }
        }
    }

    // trying to load the "requestedUrl"
    webView.loadUrl(requestedUrl)

    // waiting until the "onPageStarted" is called
    await().until { resultUrl != null }

    // now check the equality of URLs
    assertThat(resultUrl).isEqualToIgnoringCase(requestedUrl)
}

Answer 2

如果您正在使用 kotlinx-coroutines-test，您可以使用 CompletableDeferred 等待。

    @Test
    fun `should set the correct settings of the WebView`() = runTest {
        val urlDeferred = CompletableDeferred<String>(coroutineContext.job)

        // Arrange the webView
        val webView = WebView(ApplicationProvider.getApplicationContext())

        // Act by calling the setPageStatus
        webFragment.setPageStatus(webView) { pageStatusResult ->
            when(pageStatusResult) {
                is PageStatusResult.PageStarted -> {
                    urlDeferred.complete(pageStatusResult.url)
                }
            }
        }

        // Call the onPageStarted on the webViewClient and and assert in the when statement
        webView.webViewClient.onPageStarted(webView, "http://google.com", null)

        // Await at most MAX_WAITING milliseconds
        val url = withTimeout(MAX_WAITING) { urlDeferred.await() }

        // Assert that the url is correct
        assertThat(url).isEqualToIgnoringCase("http://google.com")
    }

单元测试 WebView 的 WebViewClient 回调的 onPageStarted 和 onPageFinished

Unit testing the onPageStarted and onPageFinished of a WebView's WebViewClient callbacks

android

unit-testing

android-webview

kotlin