Start tests for the sticky concurrency limited channel.

dialogue-core/src/main/java/com/palantir/dialogue/core/StickyConcurrencyLimitedChannel.java

@@ -16,6 +16,7 @@
 
 package com.palantir.dialogue.core;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.palantir.dialogue.Endpoint;
 import com.palantir.dialogue.Request;
@@ -31,13 +32,17 @@ final class StickyConcurrencyLimitedChannel implements LimitedChannel {
 
     private static final Logger log = LoggerFactory.getLogger(StickyConcurrencyLimitedChannel.class);
 
-    private final LimitedChannel delegate;
+    private final NeverThrowLimitedChannel delegate;
     private final CautiousIncreaseAggressiveDecreaseConcurrencyLimiter limiter;
     private final String channelNameForLogging;
 
-    StickyConcurrencyLimitedChannel(LimitedChannel delegate, String channelNameForLogging) {
-        this.delegate = delegate;
-        this.limiter = new CautiousIncreaseAggressiveDecreaseConcurrencyLimiter(Behavior.STICKY);
+    @VisibleForTesting
+    StickyConcurrencyLimitedChannel(
+            LimitedChannel delegate,
+            CautiousIncreaseAggressiveDecreaseConcurrencyLimiter limiter,
+            String channelNameForLogging) {
+        this.delegate = new NeverThrowLimitedChannel(delegate);
+        this.limiter = limiter;
         this.channelNameForLogging = channelNameForLogging;
     }
 
@@ -58,7 +63,7 @@ public Optional<ListenableFuture<Response>> maybeExecute(
             Optional<ListenableFuture<Response>> result = delegate.maybeExecute(
                     endpoint,
                     request,
-                    permit.isOnlyInFlight()
+                    permit.isOnlyInFlight() || limitEnforcement == LimitEnforcement.DANGEROUS_BYPASS_LIMITS
                             ? LimitEnforcement.DANGEROUS_BYPASS_LIMITS
                             : LimitEnforcement.DEFAULT_ENABLED);
             if (result.isPresent()) {
@@ -75,7 +80,8 @@ public Optional<ListenableFuture<Response>> maybeExecute(
     }
 
     static LimitedChannel create(LimitedChannel channel, String channelName) {
-        return new StickyConcurrencyLimitedChannel(channel, channelName);
+        return new StickyConcurrencyLimitedChannel(
+                channel, new CautiousIncreaseAggressiveDecreaseConcurrencyLimiter(Behavior.STICKY), channelName);
     }
 
     private void logPermitAcquired() {

dialogue-core/src/test/java/com/palantir/dialogue/core/StickyConcurrencyLimitedChannelTest.java

@@ -0,0 +1,57 @@
+/*
+ * (c) Copyright 2021 Palantir Technologies Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.palantir.dialogue.core;
+
+import com.google.common.util.concurrent.SettableFuture;
+import com.palantir.dialogue.Endpoint;
+import com.palantir.dialogue.Request;
+import com.palantir.dialogue.Response;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+public final class StickyConcurrencyLimitedChannelTest {
+
+    @Mock
+    private Endpoint endpoint;
+
+    @Mock
+    private Request request;
+
+    @Mock
+    private LimitedChannel delegate;
+
+    @Mock
+    private CautiousIncreaseAggressiveDecreaseConcurrencyLimiter mockLimiter;
+
+    @Mock
+    private Response response;
+
+    private LimitedChannel channel;
+    private SettableFuture<Response> responseFuture;
+
+    @BeforeEach
+    public void before() {
+        channel = new StickyConcurrencyLimitedChannel(delegate, mockLimiter, "test");
+    }
+
+    @Test
+    public void testLimiterAvailable_successfulRequest_host() {}
+}