Issue 2443: karate mock server interceptor

karate-core/src/main/java/com/intuit/karate/core/MockHandler.java

@@ -77,20 +77,23 @@ public class MockHandler implements ServerHandler {
     protected static final ThreadLocal<Request> LOCAL_REQUEST = new ThreadLocal<>();
     private final String prefix;
 
+    private final MockInterceptor mockInterceptor;
+
     public MockHandler(Feature feature) {
         this(feature, null);
     }
 
     public MockHandler(Feature feature, Map<String, Object> args) {
-        this(null, Collections.singletonList(feature), args);
+        this(null, Collections.singletonList(feature), args, null);
     }
 
     public MockHandler(List<Feature> features) {
-        this(null, features, null);
+        this(null, features, null, null);
     }
 
-    public MockHandler(String prefix, List<Feature> features, Map<String, Object> args) {
+    public MockHandler(String prefix, List<Feature> features, Map<String, Object> args, MockInterceptor interceptor) {
         this.prefix = "/".equals(prefix) ? null : prefix;
+        this.mockInterceptor = interceptor;
         features.forEach(feature -> {
             ScenarioRuntime runtime = initRuntime(feature, args);
             corsEnabled = corsEnabled || runtime.engine.getConfig().isCorsEnabled();
@@ -225,6 +228,9 @@ public synchronized Response handle(Request req) { // note the [synchronized]
                     if (prevEngine != null) {
                         ScenarioEngine.set(prevEngine);
                     }
+                    if (mockInterceptor != null) {
+                        mockInterceptor.intercept(req, res, scenario);
+                    }
                     return res;
                 }
             }

karate-core/src/main/java/com/intuit/karate/core/MockInterceptor.java

@@ -0,0 +1,11 @@
+package com.intuit.karate.core;
+
+import com.intuit.karate.http.Request;
+import com.intuit.karate.http.Response;
+
+@FunctionalInterface
+public interface MockInterceptor {
+
+  void intercept(Request req, Response res, Scenario scenario);
+
+}

karate-core/src/main/java/com/intuit/karate/core/MockServer.java

@@ -68,6 +68,7 @@ public static class Builder {
         File keyFile;
         Map<String, Object> args;
         String prefix = null;
+        MockInterceptor interceptor = null;
 
         public Builder watch(boolean value) {
             watch = value;
@@ -116,6 +117,11 @@ public Builder arg(String name, Object value) {
             return this;
         }
 
+        public Builder interceptor(MockInterceptor value) {
+            interceptor = value;
+            return this;
+        }
+
         public MockServer build() {
             ServerBuilder sb = Server.builder();
             sb.requestTimeoutMillis(0);
@@ -129,7 +135,7 @@ public MockServer build() {
             } else {
                 sb.http(port);
             }
-            ServerHandler handler = watch ? new ReloadingMockHandler(features, args, prefix) : new MockHandler(prefix, features, args);
+            ServerHandler handler = watch ? new ReloadingMockHandler(features, args, prefix, interceptor) : new MockHandler(prefix, features, args, interceptor);
             HttpService service = new HttpServerHandler(handler);
             sb.service("prefix:" + (prefix == null ? "/" : prefix), service);
             return new MockServer(sb);
@@ -143,23 +149,25 @@ private static class ReloadingMockHandler implements ServerHandler {
         private MockHandler handler;
         private final LinkedHashMap<File, Long> files = new LinkedHashMap<>();
         private final String prefix;
+        private final MockInterceptor interceptor;
 
-        public ReloadingMockHandler(List<Feature> features, Map<String, Object> args, String prefix) {
+        public ReloadingMockHandler(List<Feature> features, Map<String, Object> args, String prefix, MockInterceptor interceptor) {
             this.args = args;
             this.prefix = prefix;
+            this.interceptor = interceptor;
             for (Feature f : features) {
                 this.files.put(f.getResource().getFile(), f.getResource().getFile().lastModified());
             }
             logger.debug("watch mode init - {}", files);
-            handler = new MockHandler(prefix, features, args);
+            handler = new MockHandler(prefix, features, args, this.interceptor);
         }
 
         @Override
         public Response handle(Request request) {
             boolean reload = files.entrySet().stream().reduce(false, (modified, entry) -> entry.getKey().lastModified() > entry.getValue(), (a, b) -> a || b);
             if (reload) {
                 List<Feature> features = files.keySet().stream().map(f -> Feature.read(f)).collect(Collectors.toList());
-                handler = new MockHandler(prefix, features, args);
+                handler = new MockHandler(prefix, features, args, interceptor);
             }
             return handler.handle(request);
         }

karate-core/src/test/java/com/intuit/karate/core/mock/MockTest.java

@@ -1,10 +1,13 @@
 package com.intuit.karate.core.mock;
 
-import com.intuit.karate.http.HttpServer;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import com.intuit.karate.Results;
 import com.intuit.karate.Runner;
 import com.intuit.karate.core.MockServer;
-import static org.junit.jupiter.api.Assertions.*;
+import com.intuit.karate.http.HttpServer;
+import java.util.concurrent.atomic.AtomicInteger;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
@@ -18,11 +21,16 @@ class MockTest {
 
     static final Logger logger = LoggerFactory.getLogger(MockTest.class);
 
+    static final AtomicInteger count = new AtomicInteger(0);
+
     static HttpServer startMockServer() {
         MockServer server = MockServer.featurePaths(
                 "classpath:com/intuit/karate/core/mock/_simple.feature",
                 "classpath:com/intuit/karate/core/mock/_mock.feature")
                 .pathPrefix("/") // ensure cli default works
+                .interceptor((req, res, scenario) ->
+                        logger.debug("interceptor has been called %s times"
+                            .formatted(count.incrementAndGet())))
                 .build();
         System.setProperty("karate.server.port", server.getPort() + "");
         return server;
@@ -39,6 +47,7 @@ void testMock() {
                 .configDir("classpath:com/intuit/karate/core/mock")
                 .parallel(1);
         assertEquals(0, results.getFailCount(), results.getErrorMessages());
+        assertTrue(count.get() > 0);
     }
 
 }