Fix coverage

Author: manuel-alvarez-alvarez

telemetry/src/main/java/datadog/telemetry/endpoint/EndpointPeriodicAction.java

@@ -21,9 +21,37 @@ public EndpointPeriodicAction(EndpointCollector collector) {
   @Override
   public void doIteration(final TelemetryService service) {
     for (final Iterator<Endpoint> it = collector.drain(); it.hasNext(); ) {
-      if (!service.addEndpoint(it.next())) {
+      final Endpoint endpoint = it.next();
+      if (!service.addEndpoint(endpoint)) {
+        collector.supplier(new HeadAndTailIterator(endpoint, it)); // try again latter
         break;
       }
     }
   }
+
+  private static final class HeadAndTailIterator implements Iterator<Endpoint> {
+    private final Endpoint head;
+    private final Iterator<Endpoint> tail;
+    private boolean first;
+
+    private HeadAndTailIterator(final Endpoint head, final Iterator<Endpoint> tail) {
+      this.head = head;
+      this.tail = tail;
+      first = true;
+    }
+
+    @Override
+    public boolean hasNext() {
+      return first || tail.hasNext();
+    }
+
+    @Override
+    public Endpoint next() {
+      if (first) {
+        first = false;
+        return head;
+      }
+      return tail.next();
+    }
+  }
 }

telemetry/src/test/groovy/datadog/telemetry/endpoint/EndpointPeriodicActionTest.groovy

@@ -7,19 +7,48 @@ import spock.lang.Specification
 
 class EndpointPeriodicActionTest extends Specification {
 
-  void 'test that common metrics are joined before being sent to telemetry #iterationIndex'() {
+  void 'test that endpoints are captured by the periodic action'() {
     given:
     final endpoint = new Endpoint().first(true).type('REST').method("GET").operation('http.request').path("/test")
     final service = Mock(TelemetryService)
-    final endpointCollector = Mock(EndpointCollector)
+    final endpointCollector = new EndpointCollector()
+    endpointCollector.supplier([endpoint].iterator())
     final action = new EndpointPeriodicAction(endpointCollector)
 
     when:
     action.doIteration(service)
 
     then:
-    1 * endpointCollector.drain() >> [endpoint].iterator()
     1 * service.addEndpoint(endpoint)
     0 * _
   }
+
+  void 'test that endpoints are not lost if the service is at capacity'() {
+    given:
+    final endpoints = [
+      new Endpoint().first(true).type('REST').method("GET").operation('http.request').path("/test1"),
+      new Endpoint().type('REST').method("GET").operation('http.request').path("/test2"),
+      new Endpoint().type('REST').method("GET").operation('http.request').path("/test3"),
+    ]
+    final service = Mock(TelemetryService)
+    final endpointCollector = new EndpointCollector()
+    endpointCollector.supplier(endpoints.iterator())
+    final action = new EndpointPeriodicAction(endpointCollector)
+
+    when:
+    action.doIteration(service)
+
+    then:
+    1 * service.addEndpoint(endpoints[0]) >> true
+    1 * service.addEndpoint(endpoints[1]) >> false
+    0 * _
+
+    when:
+    action.doIteration(service)
+
+    then:
+    1 * service.addEndpoint(endpoints[1]) >> true
+    1 * service.addEndpoint(endpoints[2]) >> true
+    0 * _
+  }
 }