单元测试WebView的WebViewClient回调的onPageStarted和onPageFinished

Question

Android Studio 3.5.1
Kotlin 1.3

我有以下尝试进行单元测试的方法。使用WebView和WebViewClient

我拥有的方法如下，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 ?: ""))
        }
    }
}

我采用了一个WebView，它覆盖了WebViewClient的某些回调。然后在onPageStarted或onPageFinished中调用lambda函数。

使用密封的类来设置在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webView.webViewClient.onPageStarted，因此您应该使用异步测试方法，而不是自己同步调用。通过这种方式，我们将URL传递WebView给显示，然后等待该onPageStarted方法WebView本身被调用。

似乎在Android中运行异步单元测试的最佳选择是使用Awaitility。

build.gradle

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

单元测试班

@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)
}