Add debug message pre and post hooks

packages/node_modules/@node-red/nodes/core/common/lib/debug/debug-utils.js

@@ -392,12 +392,28 @@ RED.debug = (function() {
         if (o) { stack.push(o); }
         if (!busy && (stack.length > 0)) {
             busy = true;
-            processDebugMessage(stack.shift());
-            setTimeout(function() {
-                busy = false;
-                handleDebugMessage();
-            }, 15);  // every 15mS = 66 times a second
-            if (stack.length > numMessages) { stack = stack.splice(-numMessages); }
+            const message = stack.shift()
+            // call any preDebugLog hooks, allowing them to modify the message or block it from being displayed
+            RED.hooks.trigger('debugPreProcessMessage', { message }).then(result => {
+                if (result === false) {
+                    return false; // A hook returned false - halt processing of this message
+                }
+                return processDebugMessage(message);
+            }).then(processArtifacts => {
+                if (processArtifacts === false) {
+                    return false; // A hook returned false - halt processing of this message
+                }
+                const { message, element, payload } = processArtifacts || {};
+                return RED.hooks.trigger('debugPostProcessMessage', { message, element, payload });
+            }).catch(err => {
+                console.error("Error in debug process message hooks", err);
+            }).finally(() => {
+                setTimeout(function() {
+                    busy = false;
+                    handleDebugMessage();
+                }, 15);  // every 15mS = 66 times a second
+                if (stack.length > numMessages) { stack = stack.splice(-numMessages); }
+            })
         }
     }
 
@@ -519,10 +535,13 @@ RED.debug = (function() {
             sourceId: sourceNode && sourceNode.id,
             rootPath: path,
             nodeSelector: config.messageSourceClick,
-            enablePinning: true
+            enablePinning: true,
+            tools: o.tools // permit preDebugLog hooks to add extra tools to the <debugMessage> element
         });
         // Do this in a separate step so the element functions aren't stripped
         debugMessage.appendTo(el);
+        // add the meta row tools container, even if there are no tools, so that the postProcessDebugMessage hook can add tools
+        const tools = $('<span class="red-ui-debug-msg-tools button-group"></span>').appendTo(metaRow)
         // NOTE: relying on function error to have a "type" that all other msgs don't
         if (o.hasOwnProperty("type") && (o.type === "function")) {
             var errorLvlType = 'error';
@@ -534,7 +553,6 @@ RED.debug = (function() {
             msg.addClass('red-ui-debug-msg-level-' + errorLvl);
             $('<span class="red-ui-debug-msg-topic">function : (' + errorLvlType + ')</span>').appendTo(metaRow);
         } else {
-            var tools = $('<span class="red-ui-debug-msg-tools button-group"></span>').appendTo(metaRow);
             var filterMessage = $('<button class="red-ui-button red-ui-button-small"><i class="fa fa-caret-down"></i></button>').appendTo(tools);
             filterMessage.on("click", function(e) {
                 e.preventDefault();
@@ -590,6 +608,14 @@ RED.debug = (function() {
         if (atBottom) {
             messageList.scrollTop(sbc.scrollHeight);
         }
+
+        // return artifacts to permit postProcessDebugMessage hooks to modify the message element, access the
+        // processed payload or otherwise modify the message after it has been generated.
+        return {
+            message: o, // original debug message object, useful for any hook that might have tagged additional info onto it
+            element: msg, // the top-level element for this debug message
+            payload // the reconstructed debug message
+        }
     }
 
     function clearMessageList(clearFilter, filteredOnly) {