refactor: extend logging for happy cases (#66)

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## References

#65

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upstream and downstream changes -->

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src/main/java/org/wiremock/extensions/state/extensions/DeleteStateEventListener.java

@@ -32,6 +32,8 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import static org.wiremock.extensions.state.internal.ExtensionLogger.logger;
+
 /**
  * Event listener to trigger state context deletion.
  * <p>
@@ -75,41 +77,63 @@ public void beforeResponseSent(ServeEvent serveEvent, Parameters parameters) {
 
     private void handleListDeletion(DeleteStateParameters.ListParameters listConfig, String contextName, Map<String, Object> model) {
         if (Boolean.TRUE.equals(listConfig.getDeleteFirst())) {
-            contextManager.createOrUpdateContextList(contextName, maps -> {
-                if (!maps.isEmpty()) maps.removeFirst();
-            });
+            deleteFirst(contextName);
         } else if (Boolean.TRUE.equals(listConfig.getDeleteLast())) {
-            contextManager.createOrUpdateContextList(contextName, maps -> {
-                if (!maps.isEmpty()) maps.removeLast();
-            });
+            deleteLast(contextName);
         } else if (StringUtils.isNotBlank(listConfig.getDeleteIndex())) {
-            try {
-                var index = Integer.parseInt(renderTemplate(model, listConfig.getDeleteIndex()));
-                contextManager.createOrUpdateContextList(contextName, list -> list.remove(index));
-            } catch (IndexOutOfBoundsException | NumberFormatException e) {
-                throw createConfigurationError("List index '%s' does not exist or cannot be parsed: %s", listConfig.getDeleteIndex(), e.getMessage());
-            }
+            deleteIndex(listConfig, contextName, model);
         } else if (listConfig.getDeleteWhere() != null &&
             listConfig.getDeleteWhere().getProperty() != null &&
             listConfig.getDeleteWhere().getValue() != null
         ) {
-            var property = renderTemplate(model, listConfig.getDeleteWhere().getProperty());
-            var value = renderTemplate(model, listConfig.getDeleteWhere().getValue());
+            deleteWhere(listConfig, contextName, model);
+        } else {
+            throw createConfigurationError("Missing/invalid configuration for list: ");
+        }
+    }
+
+    private Long deleteFirst(String contextName) {
+        return contextManager.createOrUpdateContextList(contextName, maps -> {
+            if (!maps.isEmpty()) maps.removeFirst();
+            logger().info(contextName, "list::deleteFirst");
+        });
+    }
+
+    private void deleteLast(String contextName) {
+        contextManager.createOrUpdateContextList(contextName, maps -> {
+            if (!maps.isEmpty()) maps.removeLast();
+            logger().info(contextName, "list::deleteLast");
+        });
+    }
+
+    private void deleteIndex(DeleteStateParameters.ListParameters listConfig, String contextName, Map<String, Object> model) {
+        try {
+            var index = Integer.parseInt(renderTemplate(model, listConfig.getDeleteIndex()));
             contextManager.createOrUpdateContextList(contextName, list -> {
-                var iterator = list.iterator();
-                while (iterator.hasNext()) {
-                    var element = iterator.next();
-                    if (Objects.equals(element.getOrDefault(property, null), value)) {
-                        iterator.remove();
-                        break;
-                    }
-                }
+                list.remove(index);
+                logger().info(contextName, String.format("list::deleteIndex(%d)", index));
             });
-        } else {
-            throw createConfigurationError("Missing/invalid configuration for list");
+        } catch (IndexOutOfBoundsException | NumberFormatException e) {
+            throw createConfigurationError("List index '%s' does not exist or cannot be parsed: %s", listConfig.getDeleteIndex(), e.getMessage());
         }
     }
 
+    private void deleteWhere(DeleteStateParameters.ListParameters listConfig, String contextName, Map<String, Object> model) {
+        var property = renderTemplate(model, listConfig.getDeleteWhere().getProperty());
+        var value = renderTemplate(model, listConfig.getDeleteWhere().getValue());
+        contextManager.createOrUpdateContextList(contextName, list -> {
+            var iterator = list.iterator();
+            while (iterator.hasNext()) {
+                var element = iterator.next();
+                if (Objects.equals(element.getOrDefault(property, null), value)) {
+                    iterator.remove();
+                    logger().info(contextName, String.format("list::deleteWhere(property=%s)", property));
+                    break;
+                }
+            }
+        });
+    }
+
     private String createContextName(Map<String, Object> model, DeleteStateParameters parameters) {
         var rawContext = Optional.ofNullable(parameters.getContext()).filter(StringUtils::isNotBlank).orElseThrow(() -> new ConfigurationException("no context specified"));
         String context = renderTemplate(model, rawContext);

src/main/java/org/wiremock/extensions/state/extensions/RecordStateEventListener.java

@@ -32,6 +32,8 @@
 import java.util.Optional;
 import java.util.stream.Collectors;
 
+import static org.wiremock.extensions.state.internal.ExtensionLogger.logger;
+
 /**
  * Event listener to trigger state context recording.
  * <p>
@@ -88,16 +90,31 @@ private void handleList(String contextName, Map<String, Object> model, RecordSta
         Optional.ofNullable(parameters.getList())
             .ifPresent(listConfiguration -> {
                     Optional.ofNullable(listConfiguration.getAddFirst())
-                        .ifPresent(configuration ->
-                        contextManager.createOrUpdateContextList(contextName, list -> list.addFirst(getPropertiesFromConfiguration(model, configuration))));
-                    Optional.ofNullable(listConfiguration.getAddLast()).ifPresent(configuration ->
-                        contextManager.createOrUpdateContextList(contextName, list -> list.addLast(getPropertiesFromConfiguration(model, configuration))));
+                        .ifPresent(configuration -> addFirst(contextName, model, configuration));
+                    Optional.ofNullable(listConfiguration.getAddLast())
+                        .ifPresent(configuration -> addLast(contextName, model, configuration));
                 }
             );
     }
 
+    private Long addFirst(String contextName, Map<String, Object> model, Map<String, String> configuration) {
+        return contextManager.createOrUpdateContextList(contextName, list -> {
+            list.addFirst(getPropertiesFromConfiguration(model, configuration));
+            logger().info(contextName, "list::addFirst");
+        });
+    }
+
+    private Long addLast(String contextName, Map<String, Object> model, Map<String, String> configuration) {
+        return contextManager.createOrUpdateContextList(contextName, list -> {
+            list.addLast(getPropertiesFromConfiguration(model, configuration));
+            logger().info(contextName, "list::addLast");
+        });
+    }
+
     private String createContextName(Map<String, Object> model, Parameters parameters) {
-        var rawContext = Optional.ofNullable(parameters.getString("context")).filter(StringUtils::isNotBlank).orElseThrow(() -> new ConfigurationException("no context specified"));
+        var rawContext = Optional.ofNullable(parameters.getString("context"))
+            .filter(StringUtils::isNotBlank)
+            .orElseThrow(() -> new ConfigurationException("no context specified"));
         String context = renderTemplate(model, rawContext);
         if (StringUtils.isBlank(context)) {
             throw createConfigurationError("context cannot be blank");

src/main/java/org/wiremock/extensions/state/extensions/StateHandlerbarHelper.java

@@ -31,6 +31,7 @@
 import java.util.stream.Stream;
 
 import static com.github.tomakehurst.wiremock.common.LocalNotifier.notifier;
+import static org.wiremock.extensions.state.internal.ExtensionLogger.logger;
 
 /**
  * Response templating helper to access state.
@@ -84,7 +85,11 @@ private Optional<Object> getProperty(String contextName, String property, String
                     .map(it -> it.getFromContext(context))
                     .orElseGet(() -> context.getProperties().get(property))
             )
-            .or(() -> convertToPropertySpecificDefault(property, defaultValue));
+            .or(() -> convertToPropertySpecificDefault(property, defaultValue))
+            .map((obj) -> {
+                logger().info(contextName, String.format("handlebar(property=%s)", property));
+                return obj;
+            });
     }
 
     private Optional<Object> convertToPropertySpecificDefault(String property, String defaultValue) {
@@ -104,6 +109,10 @@ private Optional<Object> getList(String contextName, String list) {
                     notifier().info("Path query failed: " + e.getMessage());
                     return Optional.empty();
                 }
+            })
+            .map((obj) -> {
+                logger().info(contextName, "handlebar(list)");
+                return obj;
             });
     }
 

src/main/java/org/wiremock/extensions/state/extensions/StateRequestMatcher.java

@@ -35,6 +35,7 @@
 import java.util.stream.Collectors;
 
 import static com.github.tomakehurst.wiremock.common.LocalNotifier.notifier;
+import static org.wiremock.extensions.state.internal.ExtensionLogger.logger;
 
 /**
  * Request matcher for state.
@@ -82,6 +83,7 @@ private MatchResult hasContext(Map<String, Object> model, Parameters parameters,
             .map(context -> {
                 List<Map.Entry<ContextMatcher, Object>> matchers = getMatches(parameters);
                 if (matchers.isEmpty()) {
+                    logger().info(context, "hasContext matched");
                     return MatchResult.exactMatch();
                 } else {
                     return calculateMatch(model, context, matchers);
@@ -103,6 +105,7 @@ private MatchResult calculateMatch(Map<String, Object> model, Context context, L
     private MatchResult hasNotContext(Map<String, Object> model, String template) {
         var context = renderTemplate(model, template);
         if (contextManager.getContext(context).isEmpty()) {
+            logger().info(context, "hasNotContext matched");
             return MatchResult.exactMatch();
         } else {
             return MatchResult.noMatch();

src/main/java/org/wiremock/extensions/state/internal/ContextManager.java

@@ -21,6 +21,9 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+import static org.wiremock.extensions.state.internal.ExtensionLogger.logger;
 
 public class ContextManager {
 
@@ -30,6 +33,11 @@ public ContextManager(Store<String, Object> store) {
         this.store = store;
     }
 
+    private static Supplier<Context> createNewContext(String contextName) {
+        logger().info(contextName, "created");
+        return () -> new Context(contextName);
+    }
+
     public Object getState(String contextName, String property) {
         synchronized (store) {
             return store.get(contextName).map(it -> ((Context) it).getProperties().get(property)).orElse(null);
@@ -51,6 +59,7 @@ public Optional<Context> getContext(String contextName) {
     public void deleteContext(String contextName) {
         synchronized (store) {
             store.remove(contextName);
+            logger().info(contextName, "deleted");
         }
     }
 
@@ -61,12 +70,14 @@ public Long createOrUpdateContextState(String contextName, Map<String, String> p
                 .map(it -> {
                     it.incUpdateCount();
                     return it;
-                }).orElseGet(() -> new Context(contextName));
+                }).orElseGet(createNewContext(contextName));
             properties.forEach((k, v) -> {
-                if(v.equals("null")) {
+                if (v.equals("null")) {
                     context.getProperties().remove(k);
+                    logger().info(contextName, String.format("property '%s' removed", k));
                 } else {
                     context.getProperties().put(k, v);
+                    logger().info(contextName, String.format("property '%s' updated", k));
                 }
             });
             store.put(contextName, context);
@@ -81,7 +92,7 @@ public Long createOrUpdateContextList(String contextName, Consumer<LinkedList<Ma
                 .map(it -> {
                     it.incUpdateCount();
                     return it;
-                }).orElseGet(() -> new Context(contextName));
+                }).orElseGet(createNewContext(contextName));
             consumer.accept(context.getList());
             store.put(contextName, context);
             return context.getUpdateCount();

src/main/java/org/wiremock/extensions/state/internal/ExtensionLogger.java

@@ -0,0 +1,43 @@
+package org.wiremock.extensions.state.internal;
+
+import com.github.tomakehurst.wiremock.common.Notifier;
+
+import static com.github.tomakehurst.wiremock.common.LocalNotifier.notifier;
+
+public class ExtensionLogger {
+
+    private static Notifier notifier;
+
+    private ExtensionLogger() {
+        notifier = notifier();
+    }
+
+    public static ExtensionLogger logger() {
+        return InstanceHolder.instance;
+    }
+
+    public void info(Context context, String message) {
+        notifier.info(buildMessage(context.getContextName(), message));
+    }
+
+    public void error(Context context, String message) {
+        notifier.error(buildMessage(context.getContextName(), message));
+    }
+
+    public void info(String contextName, String message) {
+        notifier.info(buildMessage(contextName, message));
+    }
+
+    public void error(String contextName, String message) {
+        notifier.error(buildMessage(contextName, message));
+    }
+
+    private String buildMessage(String contextName, String message) {
+        return String.format("Context '%s': %s", contextName, message);
+    }
+
+    private static final class InstanceHolder {
+        private static final ExtensionLogger instance = new ExtensionLogger();
+    }
+
+}