Fix: OONIAPIClientTest using failing API endpoint and incorrect testi…

…ng logic (#784)

Fixes ooni/probe#2778

## Proposed Changes

- Switch testing endpoint from `ams-pg.ooni.org` to
`https://backend-hel.ooni.org`
  - Refactor `OONIAPIClientTest` to Kotlin
  - Execute API calls synchronously to fix incorrect async logic
- Remove database operations that were irrelevant to the
`testSelectMeasurementsWithJson` test
- Remove the test `getMeasurementJsonError` because it was only testing
external libraries logic (retrofit and gson) and not the `OONIAPIClient`

app/src/main/java/org/openobservatory/ooniprobe/common/Application.java

@@ -100,10 +100,6 @@ public OONICheckInConfig getOONICheckInConfig() {
 
 	public ActivityComponent getActivityComponent() { return component.activityComponent(); }
 
-	public OkHttpClient getOkHttpClient() {
-		return _okHttpClient;
-	}
-
 	public OONIAPIClient getApiClient() {
 		return _apiClient;
 	}

app/src/test/java/org/openobservatory/ooniprobe/client/OONIAPIClientTest.kt

@@ -0,0 +1,47 @@
+package org.openobservatory.ooniprobe.client
+
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.openobservatory.ooniprobe.RobolectricAbstractTest
+
+class OONIAPIClientTest : RobolectricAbstractTest() {
+
+    @Test
+    fun measurementSuccess() {
+        val response = apiClient.getMeasurement(EXISTING_REPORT_ID, null).execute()
+
+        assertTrue(response.isSuccessful)
+        response.body().use { body ->
+            assertNotNull(body)
+            assertNotNull(body!!.string())
+        }
+    }
+
+    @Test
+    fun measurementError() {
+        val response = apiClient.getMeasurement(NON_EXISTING_REPORT_ID, null).execute()
+
+        assertFalse(response.isSuccessful)
+    }
+
+    @Test
+    fun testSelectMeasurementsWithJson() {
+        val response = apiClient.checkReportId(EXISTING_REPORT_ID).execute()
+
+        assertTrue(response.isSuccessful)
+        with(response.body()) {
+            assertNotNull(this)
+            assertTrue(this!!.found)
+        }
+    }
+
+    private val apiClient get() = a.apiClient
+
+    companion object {
+        private const val EXISTING_REPORT_ID =
+            "20190113T202156Z_AS327931_CgoC3KbgM6zKajvIIt1AxxybJ1HbjwwWJjsJnlxy9rpcGY54VH"
+        private const val NON_EXISTING_REPORT_ID = "EMPTY"
+    }
+}

shared-test/src/main/java/org/openobservatory/ooniprobe/di/TestAppModule.java

@@ -8,7 +8,7 @@
 @Module
 public class TestAppModule extends ApplicationModule {
 
-    private static final String CLIENT_URL = "https://ams-pg.ooni.org";
+    private static final String CLIENT_URL = "https://backend-hel.ooni.org";
 
     public TestAppModule(Application application) {
         super(application);