Addressing PR comments.

packages/server/src/api/controllers/script.ts

@@ -1,13 +1,11 @@
 import { Ctx } from "@budibase/types"
 import { IsolatedVM } from "../../jsRunner/vm"
+import { iifeWrapper } from "../../jsRunner/utilities"
 
 export async function execute(ctx: Ctx) {
   const { script, context } = ctx.request.body
   const vm = new IsolatedVM()
-  const result = vm.withContext(context, () =>
+  ctx.body = vm.withContext(context, () => vm.execute(iifeWrapper(script)))
-    vm.execute(`(function(){\n${script}\n})();`)
-  )
-  ctx.body = result
 }
 
 export async function save(ctx: Ctx) {

packages/server/src/jsRunner/index.ts

@@ -7,7 +7,6 @@ import {
 } from "@budibase/string-templates"
 import { context, logging } from "@budibase/backend-core"
 import tracer from "dd-trace"
-
 import { IsolatedVM } from "./vm"
 
 export function init() {

packages/server/src/jsRunner/tests/isolatedVM.spec.ts

@@ -1,17 +1,21 @@
 import fs from "fs"
 import path from "path"
 import { IsolatedVM } from "../vm"
+import { iifeWrapper } from "../utilities"
 
-function runJSWithIsolatedVM(script: string, context: any) {
+function runJSWithIsolatedVM(script: string, context: Record<string, any>) {
   const runner = new IsolatedVM()
   return runner.withContext(context, () => {
-    return runner.execute(`(function(){\n${script}\n})();`)
+    return runner.execute(iifeWrapper(script))
   })
 }
 
 describe("Test isolated vm directly", () => {
   it("should handle a very large file", () => {
-    const marked = fs.readFileSync(path.join(__dirname, "marked.txt"), "utf-8")
+    const marked = fs.readFileSync(
+      path.join(__dirname, "largeJSExample.txt"),
+      "utf-8"
+    )
     const result = runJSWithIsolatedVM(marked, {
       trigger: { row: { Message: "dddd" } },
     })
@@ -69,7 +73,14 @@ describe("Test isolated vm directly", () => {
     )
     expect(result).toBeDefined()
     expect(result.length).toBe(1)
-    expect(result[0].imageLinks.length).toBe(6)
+    expect(result[0].imageLinks).toEqual([
+      "https://budibase.com",
+      "_S/",
+      "https://budibase.com",
+      "https://budibase.com",
+      "https://budibase.com",
+      "https://budibase.com",
+    ])
   })
 
   it("should handle automation script example", () => {

packages/server/src/jsRunner/tests/jsRunner.spec.ts

@@ -74,7 +74,7 @@ describe("jsRunner (using isolated-vm)", () => {
   })
 
   // the test cases here were extracted from templates/real world examples of JS in Budibase
-  describe("should real world tests of JS", () => {
+  describe("real test cases from Budicloud", () => {
     const context = {
       "Unit Value": 2,
       Quantity: 1,

packages/server/src/jsRunner/utilities.ts

@@ -0,0 +1,3 @@
+export function iifeWrapper(script: string) {
+  return `(function(){\n${script}\n})();`
+}

packages/server/src/jsRunner/vm/isolated-vm.ts

@@ -7,6 +7,7 @@ import querystring from "querystring"
 
 import { BundleType, loadBundle } from "../bundles"
 import { VM } from "@budibase/types"
+import { iifeWrapper } from "../utilities"
 import environment from "../../environment"
 
 class ExecutionTimeoutError extends Error {
@@ -118,11 +119,11 @@ export class IsolatedVM implements VM {
     // 3. Process script
     // 4. Stringify the result in order to convert the result from BSON to json
     this.codeWrapper = code =>
-      `(function(){
+      iifeWrapper(`
-            const data = bson.deserialize(bsonData, { validation: { utf8: false } }).data;
+        const data = bson.deserialize(bsonData, { validation: { utf8: false } }).data;
-            const result = ${code}
+        const result = ${code}
-            return bson.toJson(result);
+        return bson.toJson(result);
-        })();`
+      `)
 
     const bsonSource = loadBundle(BundleType.BSON)
 

packages/server/src/threads/query.ts

@@ -8,6 +8,7 @@ import {
   QueryResponse,
 } from "./definitions"
 import { IsolatedVM } from "../jsRunner/vm"
+import { iifeWrapper } from "../jsRunner/utilities"
 import { getIntegration } from "../integrations"
 import { processStringSync } from "@budibase/string-templates"
 import { context, cache, auth } from "@budibase/backend-core"
@@ -127,7 +128,7 @@ class QueryRunner {
 
     // transform as required
     if (transformer) {
-      transformer = `(function(){\n${transformer}\n})();`
+      transformer = iifeWrapper(transformer)
       let vm = new IsolatedVM()
       if (datasource.source === SourceName.MONGODB) {
         vm = vm.withParsingBson(rows)