Clean up isolates when a request is finished.

packages/backend-core/src/context/types.ts

@@ -15,4 +15,5 @@ export type ContextMap = {
     jsContext: Context
     helpersModule: Module
   }
+  cleanup?: (() => void | Promise<void>)[]
 }

packages/server/src/jsRunner/index.ts

@@ -115,6 +115,14 @@ export function init() {
           }
 
           bbCtx.isolateRefs = { jsContext, jsIsolate, helpersModule }
+          if (!bbCtx.cleanup) {
+            bbCtx.cleanup = []
+          }
+          bbCtx.cleanup.push(() => {
+            helpersModule.release()
+            jsContext.release()
+            jsIsolate.dispose()
+          })
         }
 
         let { jsIsolate, jsContext, helpersModule } = bbCtx.isolateRefs!

packages/server/src/middleware/cleanup.ts

@@ -0,0 +1,16 @@
+import { Ctx } from "@budibase/types"
+import { context } from "@budibase/backend-core"
+
+export default async (ctx: Ctx, next: any) => {
+  const resp = next()
+
+  const current = context.getCurrentContext()
+  if (current?.cleanup) {
+    for (let fn of current.cleanup || []) {
+      await fn()
+    }
+    delete current.cleanup
+  }
+
+  return resp
+}