[WOOMOB-54] Handle empty REST API namespaces during site login

RELEASE-NOTES.txt

@@ -6,6 +6,7 @@
 -----
 - [*] Woo POS: Remote Tap to Pay failures now explain what went wrong - phone not eligible for Tap to Pay, NFC turned off, or a payment service error - instead of a generic message or raw error text [https://github.com/woocommerce/woocommerce-android/pull/16384]
 - [*] QR login now asks you to choose a store when your WordPress.com account has multiple sites instead of preselecting one [https://github.com/woocommerce/woocommerce-android/pull/16400]
+- [*] Store login now shows a connection error when a site's REST API hides its namespaces instead of continuing into misleading setup screens [https://github.com/woocommerce/woocommerce-android/pull/16408]
 - [Internal] Close analytics gaps in the Remote Tap to Pay flow: transport on the reader-ready event, cause chains in error descriptions, no stale card reader model, and a real session ended reason [https://github.com/woocommerce/woocommerce-android/pull/16368]
 - [*] Tap to Pay no longer disappears from the Payments screen shortly after it appears [https://github.com/woocommerce/woocommerce-android/pull/16370]
 - [*] Fixed a crash when pressing Back on the "You're already signed in" warning shown after opening a QR login link while signed in [https://github.com/woocommerce/woocommerce-android/pull/16347]

libs/fluxc/src/main/java/org/wordpress/android/fluxc/network/rest/wpapi/site/SiteWPAPIRestClient.kt

@@ -4,6 +4,8 @@ import com.android.volley.RequestQueue
 import okhttp3.HttpUrl.Companion.toHttpUrl
 import org.wordpress.android.fluxc.Dispatcher
 import org.wordpress.android.fluxc.model.SiteModel
+import org.wordpress.android.fluxc.network.BaseRequest.BaseNetworkError
+import org.wordpress.android.fluxc.network.BaseRequest.GenericErrorType.INVALID_RESPONSE
 import org.wordpress.android.fluxc.network.UserAgent
 import org.wordpress.android.fluxc.network.discovery.DiscoveryUtils
 import org.wordpress.android.fluxc.network.discovery.DiscoveryWPAPIRestClient
@@ -54,15 +56,21 @@ class SiteWPAPIRestClient @Inject constructor(
         return when (result) {
             is Success -> {
                 val response = result.data
+                if (response?.namespaces.isNullOrEmpty()) {
+                    return SiteModel().apply {
+                        error = BaseNetworkError(INVALID_RESPONSE)
+                    }
+                }
+
                 SiteModel().apply {
-                    name = response?.name
-                    timezone = response?.gmtOffset
+                    name = response.name
+                    timezone = response.gmtOffset
                     origin = SiteModel.ORIGIN_WPAPI
-                    hasWooCommerce = response?.namespaces?.any {
+                    hasWooCommerce = response.namespaces.any {
                         it.startsWith(WOO_API_NAMESPACE_PREFIX)
-                    } ?: false
+                    }
 
-                    applicationPasswordsAuthorizeUrl = response?.authentication?.applicationPasswords
+                    applicationPasswordsAuthorizeUrl = response.authentication?.applicationPasswords
                         ?.endpoints?.authorization
                     if (!applicationPasswordsAuthorizeUrl.isNullOrEmpty() &&
                         applicationPasswordsAuthorizeUrl.contains(APPLICATION_PASSWORDS_URL_SUFFIX)) {

libs/fluxc/src/test/java/org/wordpress/android/fluxc/network/rest/wpapi/site/SiteWPAPIRestClientTest.kt

@@ -0,0 +1,105 @@
+package org.wordpress.android.fluxc.network.rest.wpapi.site
+
+import com.android.volley.RequestQueue
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.kotlin.mock
+import org.mockito.kotlin.whenever
+import org.robolectric.RobolectricTestRunner
+import org.wordpress.android.fluxc.Dispatcher
+import org.wordpress.android.fluxc.network.BaseRequest.GenericErrorType.INVALID_RESPONSE
+import org.wordpress.android.fluxc.network.UserAgent
+import org.wordpress.android.fluxc.network.discovery.DiscoveryWPAPIRestClient
+import org.wordpress.android.fluxc.network.discovery.RootWPAPIRestResponse
+import org.wordpress.android.fluxc.network.rest.wpapi.WPAPIGsonRequestBuilder
+import org.wordpress.android.fluxc.network.rest.wpapi.WPAPIResponse.Success
+import org.wordpress.android.fluxc.store.SiteStore.FetchWPAPISitePayload
+import org.wordpress.android.fluxc.test
+
+@Suppress("UnitTestNamingRule")
+@RunWith(RobolectricTestRunner::class)
+class SiteWPAPIRestClientTest {
+    private val wpapiGsonRequestBuilder: WPAPIGsonRequestBuilder = mock()
+    private val discoveryWPAPIRestClient: DiscoveryWPAPIRestClient = mock()
+    private val dispatcher: Dispatcher = mock()
+    private val requestQueue: RequestQueue = mock()
+    private val userAgent: UserAgent = mock()
+
+    private lateinit var restClient: SiteWPAPIRestClient
+
+    @Before
+    fun setUp() {
+        restClient = SiteWPAPIRestClient(
+            wpapiGsonRequestBuilder = wpapiGsonRequestBuilder,
+            discoveryWPAPIRestClient = discoveryWPAPIRestClient,
+            dispatcher = dispatcher,
+            requestQueue = requestQueue,
+            userAgent = userAgent
+        )
+    }
+
+    @Test
+    fun `given application passwords and empty namespaces, when fetching site, then return invalid response error`() =
+        test {
+            initResponse(
+                RootWPAPIRestResponse(
+                    namespaces = emptyList(),
+                    authentication = RootWPAPIRestResponse.Authentication(
+                        applicationPasswords = RootWPAPIRestResponse.Authentication.ApplicationPasswords(
+                            endpoints = RootWPAPIRestResponse.Authentication.ApplicationPasswords.Endpoints(
+                                authorization = APPLICATION_PASSWORDS_URL
+                            )
+                        )
+                    )
+                )
+            )
+
+            val site = restClient.fetchWPAPISite(FetchWPAPISitePayload(SITE_URL))
+
+            assertThat(site.isError).isTrue()
+            assertThat(site.error.type).isEqualTo(INVALID_RESPONSE)
+            assertThat(site.applicationPasswordsAuthorizeUrl).isNull()
+        }
+
+    @Test
+    fun `given missing namespaces, when fetching site, then return invalid response error`() = test {
+        initResponse(RootWPAPIRestResponse(namespaces = null))
+
+        val site = restClient.fetchWPAPISite(FetchWPAPISitePayload(SITE_URL))
+
+        assertThat(site.isError).isTrue()
+        assertThat(site.error.type).isEqualTo(INVALID_RESPONSE)
+    }
+
+    @Test
+    fun `given non-empty namespaces without WooCommerce, when fetching site, then return non-Woo site`() = test {
+        initResponse(RootWPAPIRestResponse(namespaces = listOf("wp/v2")))
+
+        val site = restClient.fetchWPAPISite(FetchWPAPISitePayload(SITE_URL))
+
+        assertThat(site.isError).isFalse()
+        assertThat(site.hasWooCommerce).isFalse()
+    }
+
+    private suspend fun initResponse(response: RootWPAPIRestResponse) {
+        whenever(discoveryWPAPIRestClient.discoverWPAPIBaseURL(SITE_URL)).thenReturn(WP_API_URL)
+        whenever(
+            wpapiGsonRequestBuilder.syncGetRequest(
+                restClient = restClient,
+                url = WP_API_URL,
+                clazz = RootWPAPIRestResponse::class.java,
+                params = mapOf("_fields" to FETCH_API_CALL_FIELDS)
+            )
+        ).thenReturn(Success(response, emptyList()))
+    }
+
+    companion object {
+        private const val SITE_URL = "https://example.com"
+        private const val WP_API_URL = "$SITE_URL/wp-json/"
+        private const val APPLICATION_PASSWORDS_URL = "$SITE_URL/wp-admin/authorize-application.php"
+        private const val FETCH_API_CALL_FIELDS =
+            "name,description,gmt_offset,url,authentication,namespaces"
+    }
+}