Added signal and listen back to karate object

README.md

@@ -3066,6 +3066,7 @@ Operation | Description
 <a name="karate-get"><code>karate.get(name)</code></a> | get the value of a variable by name (or JsonPath expression), if not found - this returns `null` which is easier to handle in JavaScript (than `undefined`)
 <a name="karate-info"><code>karate.info</code></a> | within a test (or within the [`afterScenario`](#configure) function if configured) you can access metadata such as the `Scenario` name, refer to this example: [`hooks.feature`](karate-demo/src/test/java/demo/hooks/hooks.feature)
 <a name="karate-jsonpath"><code>karate.jsonPath(json, expression)</code></a> | brings the power of [JsonPath](https://github.com/json-path/JsonPath) into JavaScript, and you can find an example [here](karate-junit4/src/test/java/com/intuit/karate/junit4/demos/js-arrays.feature).
+<a name="karate-listen"><code>karate.listen(timeout)</code></a> | wait until [`karate.signal(result)`](#karate-signal) has been called or time-out after `timeout` milliseconds. see examples: [websocket](karate-demo/src/test/java/demo/websocket/websocket.feature) / [message-queue](karate-demo/src/test/java/mock/contract/payment-service.feature)
 <a name="karate-log"><code>karate.log(... args)</code></a> | log to the same logger (and log file) being used by the parent process, logging can be suppressed with [`configure printEnabled`](#configure) set to `false`
 <a name="karate-lowercase"><code>karate.lowerCase(object)</code></a> | useful to brute-force all keys and values in a JSON or XML payload to lower-case, useful in some cases, see [example](karate-junit4/src/test/java/com/intuit/karate/junit4/demos/lower-case.feature)
 <a name="karate-map"><code>karate.map(list, function)</code></a> | functional-style 'map' operation useful to transform list-like objects (e.g. JSON arrays), see [example](karate-junit4/src/test/java/com/intuit/karate/junit4/demos/js-arrays.feature), the second argument has to be a JS function (item, [index])
@@ -3080,6 +3081,7 @@ Operation | Description
 <a name="karate-set"><code>karate.set(name, value)</code></a> | sets the value of a variable (immediately), which may be needed in case any other routines (such as the [configured headers](#configure-headers)) depend on that variable
 <a name="karate-setpath"><code>karate.set(name, path, value)</code></a> | only needed when you need to conditionally build payload elements, especially XML. This is best explained via [an example](karate-junit4/src/test/java/com/intuit/karate/junit4/xml/xml.feature#L211), and it behaves the same way as the [`set`](#set) keyword. Also see [`eval`](#eval).
 <a name="karate-setxml"><code>karate.setXml(name, xmlString)</code></a> | rarely used, refer to the example above
+<a name="karate-signal"><code>karate.signal(result)</code></a> | trigger an event that [`karate.listen(timeout)`](#karate-listen) is waiting for, and pass the data, see examples: [websocket](karate-demo/src/test/java/demo/websocket/websocket.feature) / [message-queue](karate-demo/src/test/java/mock/contract/payment-service.feature)
 <a name="karate-tags"><code>karate.tags</code></a> | for advanced users - scripts can introspect the tags that apply to the current scope, refer to this example: [`tags.feature`](karate-junit4/src/test/java/com/intuit/karate/junit4/demos/tags.feature)
 <a name="karate-tagvalues"><code>karate.tagValues</code></a> | for even more advanced users - Karate natively supports tags in a `@name=val1,val2` format, and there is an inheritance mechanism where `Scenario` level tags can over-ride `Feature` level tags, refer to this example: [`tags.feature`](karate-junit4/src/test/java/com/intuit/karate/junit4/demos/tags.feature)
 <a name="karate-tobean"><code>karate.toBean(json, className)</code></a> | converts a JSON string or map-like object into a Java object, given the Java class name as the second argument, refer to this [file](karate-junit4/src/test/java/com/intuit/karate/junit4/demos/type-conv.feature) for an example

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

@@ -50,8 +50,13 @@
 import com.intuit.karate.netty.WebSocketClient;
 import com.jayway.jsonpath.DocumentContext;
 import com.jayway.jsonpath.JsonPath;
-
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Optional;
+import java.util.Map;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
@@ -99,7 +104,9 @@ public class ScenarioContext {
     private Function<CallContext, FeatureResult> callable;
 
     // websocket
+    private final Object LOCK = new Object();
     private List<WebSocketClient> webSocketClients = new ArrayList<>();
+    private Object signalResult;
 
     public void logLastPerfEvent(String failureMessage) {
         if (prevPerfEvent != null && executionHooks != null) {
@@ -313,6 +320,7 @@ private ScenarioContext(ScenarioContext sc, ScenarioInfo info, Logger logger) {
         prevPerfEvent = sc.prevPerfEvent;
         callResults = sc.callResults;
         webSocketClients = sc.webSocketClients;
+        signalResult = sc.signalResult;
     }
 
     public void configure(Config config) {
@@ -795,7 +803,40 @@ public WebSocketClient webSocket(String url, String subProtocol, Optional<Consum
         return webSocketClient;
     }
 
-    // driver ==================================================================       
+    public void signal(Object result) {
+        logger.trace("signal called: {}", result);
+        synchronized (LOCK) {
+            signalResult = result;
+            LOCK.notify();
+        }
+    }
+
+    public Object listen(long timeout, Runnable runnable) {
+        if (runnable != null) {
+            logger.trace("submitting listen function");
+            new Thread(runnable).start();
+        }
+        synchronized (LOCK) {
+            if (signalResult != null) {
+                logger.debug("signal arrived early ! result: {}", signalResult);
+                Object temp = signalResult;
+                signalResult = null;
+                return temp;
+            }
+            try {
+                logger.trace("entered listen wait state");
+                LOCK.wait(timeout);
+                logger.trace("exit listen wait state, result: {}", signalResult);
+            } catch (InterruptedException e) {
+                logger.error("listen timed out: {}", e.getMessage());
+            }
+            Object temp = signalResult;
+            signalResult = null;
+            return temp;
+        }
+    }
+
+    // driver ==================================================================
     //
     private void setDriver(Driver driver) {
         this.driver = driver;

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

@@ -368,6 +368,21 @@ public WebSocketClient webSocket(String url, String subProtocol, Consumer<String
         return context.webSocket(url, subProtocol, Optional.of(textHandler), Optional.of(binaryHandler));
     }
 
+    public void signal(Object result) {
+        context.signal(result);
+    }
+
+    public Object listen(long timeout, ScriptObjectMirror som) {
+        if (!som.isFunction()) {
+            throw new RuntimeException("not a JS function: " + som);
+        }
+        return context.listen(timeout, () -> Script.evalFunctionCall(som, null, context));
+    }
+
+    public Object listen(long timeout) {
+        return context.listen(timeout, null);
+    }
+
     private ScriptValue getValue(String name) {
         ScriptValue sv = context.vars.get(name);
         return sv == null ? ScriptValue.NULL : sv;

karate-core/src/main/java/com/intuit/karate/netty/WebSocketClient.java

@@ -88,8 +88,8 @@ public WebSocketClient(String url, String subProtocol, Optional<Consumer<String>
     }
 
     public WebSocketClient(String url, String subProtocol, Optional<Consumer<String>> maybeTextHandler, Optional<Consumer<byte[]>> maybeBinaryHandler) {
-        this.textHandler = maybeTextHandler.orElse(this::signal);
-        this.binaryHandler = maybeBinaryHandler.orElse(this::signal);
+        this.textHandler = maybeTextHandler.orElse(msg -> {});
+        this.binaryHandler = maybeBinaryHandler.orElse(msg -> {});
         uri = URI.create(url);
         ssl = "wss".equalsIgnoreCase(uri.getScheme());
 

karate-demo/src/test/java/demo/websocket/WebSocketClientRunner.java

@@ -8,6 +8,9 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Optional;
+import java.util.function.Consumer;
+
 /**
  *
  * @author pthomas3

karate-demo/src/test/java/demo/websocket/websocket.feature

@@ -24,11 +24,3 @@ Scenario: using the websocket instance to send as well as receive messages
     * eval ws.send('Billie')
     * def result = ws.listen(5000)
     * match result == 'hello Billie !'
-
-Scenario: perform custom action when message is received
-    * def ws = karate.webSocket(demoBaseUrl + '/websocket')
-    # will call the function myJavaScriptFunction (which is defined elsewhere) for each text message that is received
-    * eval ws.setTextHandler(function(msg){ myJavaScriptFunction() })
-    * eval ws.send('Billie')
-    * def result = ws.listen(5000)
-    * match result == 'hello Billie !'