Add full ast parsing in Function node to spot node.done calls

Fixes #2998

package.json

@@ -26,6 +26,8 @@
         }
     ],
     "dependencies": {
+        "acorn": "8.3.0",
+        "acorn-walk": "8.1.0",
         "ajv": "6.12.6",
         "async-mutex": "0.3.1",
         "basic-auth": "2.0.1",

packages/node_modules/@node-red/nodes/core/function/10-function.js

@@ -19,6 +19,8 @@ module.exports = function(RED) {
 
     var util = require("util");
     var vm = require("vm");
+    var acorn = require("acorn");
+    var acornWalk = require("acorn-walk");
 
     function sendResults(node,send,_msgid,msgs,cloneFirstMessage) {
         if (msgs == null) {
@@ -102,14 +104,7 @@ module.exports = function(RED) {
             throw new Error(RED._("function.error.externalModuleNotAllowed"));
         }
 
-        var handleNodeDoneCall = true;
 
-        // Check to see if the Function appears to call `node.done()`. If so,
-        // we will assume it is well written and does actually call node.done().
-        // Otherwise, we will call node.done() after the function returns regardless.
-        if (/node\.done\s*\(\s*\)/.test(node.func)) {
-            handleNodeDoneCall = false;
-        }
 
         var functionText = "var results = null;"+
             "results = (async function(msg,__send__,__done__){ "+
@@ -130,6 +125,26 @@ module.exports = function(RED) {
                 "};\n"+
                 node.func+"\n"+
             "})(msg,__send__,__done__);";
+
+        var handleNodeDoneCall = true;
+
+        // Check to see if the Function appears to call `node.done()`. If so,
+        // we will assume it is well written and does actually call node.done().
+        // Otherwise, we will call node.done() after the function returns regardless.
+        if (/node\.done\s*\(\s*\)/.test(functionText)) {
+            // We have spotted the code contains `node.done`. It could be in a comment
+            // so need to do the extra work to parse the AST and examine it properly.
+            acornWalk.simple(acorn.parse(functionText,{ecmaVersion: "latest"} ), {
+                CallExpression(astNode) {
+                    if (astNode.callee && astNode.callee.object) {
+                        if (astNode.callee.object.name === "node" && astNode.callee.property.name === "done") {
+                            handleNodeDoneCall = false;
+                        }
+                    }
+                }
+            })
+        }
+
         var finScript = null;
         var finOpt = null;
         node.topic = n.topic;

packages/node_modules/@node-red/nodes/package.json

@@ -15,6 +15,8 @@
         }
     ],
     "dependencies": {
+        "acorn": "8.3.0",
+        "acorn-walk": "8.1.0",
         "ajv": "6.12.6",
         "body-parser": "1.19.0",
         "cheerio": "0.22.0",