feat: introduced retry rules for flaky android push tests

Author: ttypic

android/src/androidTest/java/io/ably/lib/test/RetryTestRule.java

@@ -0,0 +1,49 @@
+package io.ably.lib.test;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+
+public class RetryTestRule implements TestRule {
+
+    private final int timesToRunTestCount;
+
+    /**
+     * If `times` is 0, then we should run the test once.
+     */
+    public RetryTestRule(int times) {
+        this.timesToRunTestCount = times + 1;
+    }
+
+    @Override
+    public Statement apply(Statement base, Description description) {
+        return statement(base, description);
+    }
+
+    private Statement statement(Statement base, Description description) {
+        return new Statement() {
+
+            @Override
+            public void evaluate() throws Throwable {
+                Throwable latestException = null;
+
+                for (int i = 0; i < timesToRunTestCount; i++) {
+                    try {
+                        base.evaluate();
+                        return;
+                    } catch (Throwable t) {
+                        latestException = t;
+                        System.err.println("${description.methodName}: test failed on run: `$runCount`. Will run a maximum of `$timesToRunTestCount` times.");
+                        t.printStackTrace();
+                    }
+                }
+
+                if (latestException != null) {
+                    System.err.println("${description.displayName}: giving up after `$timesToRunTestCount` failures");
+                    throw latestException;
+                }
+            }
+        };
+    }
+}

android/src/androidTest/java/io/ably/lib/test/android/AndroidPushTest.java

@@ -41,6 +41,7 @@
 import io.ably.lib.rest.Auth;
 import io.ably.lib.rest.Channel;
 import io.ably.lib.rest.DeviceDetails;
+import io.ably.lib.test.RetryTestRule;
 import io.ably.lib.test.common.Helpers;
 import io.ably.lib.test.common.Helpers.AsyncWaiter;
 import io.ably.lib.test.common.Helpers.CompletionWaiter;
@@ -60,6 +61,7 @@
 
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -86,6 +88,9 @@
 public class AndroidPushTest {
     private static final int TIMEOUT_SECONDS = 30;
 
+    @Rule
+    public RetryTestRule retryRule = new RetryTestRule(2);
+
     private class TestActivation {
         private Helpers.RawHttpTracker httpTracker;
         private AblyRest rest;