From 37033dd4689b89825bee911fef2b87c7b4fcf49e Mon Sep 17 00:00:00 2001
From: Adria Navarro <adria@budibase.com>
Date: Wed, 24 Jan 2024 18:03:09 +0100
Subject: [PATCH] Handle js timeouts

---
 packages/server/src/jsRunner.ts         | 168 +++++++++++++-----------
 packages/string-templates/src/errors.js |  11 ++
 packages/string-templates/src/index.cjs |   5 +
 packages/string-templates/src/index.js  |   5 +
 packages/string-templates/src/index.mjs |   2 +
 5 files changed, 111 insertions(+), 80 deletions(-)
 create mode 100644 packages/string-templates/src/errors.js

diff --git a/packages/server/src/jsRunner.ts b/packages/server/src/jsRunner.ts
index e2033eab33..14ad5bedaa 100644
--- a/packages/server/src/jsRunner.ts
+++ b/packages/server/src/jsRunner.ts
@@ -1,6 +1,6 @@
 import ivm from "isolated-vm"
 import env from "./environment"
-import { setJSRunner } from "@budibase/string-templates"
+import { setJSRunner, JsErrorTimeout } from "@budibase/string-templates"
 import { context } from "@budibase/backend-core"
 import tracer from "dd-trace"
 import fs from "fs"
@@ -22,14 +22,15 @@ class ExecutionTimeoutError extends Error {
 export function init() {
   setJSRunner((js: string, ctx: Record<string, any>) => {
     return tracer.trace("runJS", {}, span => {
-      const bbCtx = context.getCurrentContext()!
+      try {
+        const bbCtx = context.getCurrentContext()!
 
-      const isolateRefs = bbCtx.isolateRefs
-      if (!isolateRefs) {
-        const jsIsolate = new ivm.Isolate({ memoryLimit: 64 })
-        const jsContext = jsIsolate.createContextSync()
+        const isolateRefs = bbCtx.isolateRefs
+        if (!isolateRefs) {
+          const jsIsolate = new ivm.Isolate({ memoryLimit: 64 })
+          const jsContext = jsIsolate.createContextSync()
 
-        const injectedRequire = `const require = function(val){
+          const injectedRequire = `const require = function(val){
         switch (val) {
           case "url": 
             return {
@@ -39,97 +40,104 @@ export function init() {
         }
       };`
 
-        const global = jsContext.global
-        global.setSync(
-          "urlResolveCb",
-          new ivm.Callback((...params: Parameters<typeof url.resolve>) =>
-            url.resolve(...params)
+          const global = jsContext.global
+          global.setSync(
+            "urlResolveCb",
+            new ivm.Callback((...params: Parameters<typeof url.resolve>) =>
+              url.resolve(...params)
+            )
           )
-        )
 
-        global.setSync(
-          "urlParseCb",
-          new ivm.Callback((...params: Parameters<typeof url.parse>) =>
-            url.parse(...params)
+          global.setSync(
+            "urlParseCb",
+            new ivm.Callback((...params: Parameters<typeof url.parse>) =>
+              url.parse(...params)
+            )
           )
-        )
 
-        const helpersModule = jsIsolate.compileModuleSync(
-          `${injectedRequire};${helpersSource}`
-        )
+          const helpersModule = jsIsolate.compileModuleSync(
+            `${injectedRequire};${helpersSource}`
+          )
 
-        const cryptoModule = jsIsolate.compileModuleSync(`export default {
+          const cryptoModule = jsIsolate.compileModuleSync(`export default {
         randomUUID: cryptoRandomUUIDCb,
       }`)
-        cryptoModule.instantiateSync(jsContext, specifier => {
-          throw new Error(`No imports allowed. Required: ${specifier}`)
-        })
+          cryptoModule.instantiateSync(jsContext, specifier => {
+            throw new Error(`No imports allowed. Required: ${specifier}`)
+          })
 
-        global.setSync(
-          "cryptoRandomUUIDCb",
-          new ivm.Callback(
-            (...params: Parameters<typeof crypto.randomUUID>) => {
-              return crypto.randomUUID(...params)
-            }
+          global.setSync(
+            "cryptoRandomUUIDCb",
+            new ivm.Callback(
+              (...params: Parameters<typeof crypto.randomUUID>) => {
+                return crypto.randomUUID(...params)
+              }
+            )
           )
+
+          helpersModule.instantiateSync(jsContext, specifier => {
+            if (specifier === "crypto") {
+              return cryptoModule
+            }
+            throw new Error(`No imports allowed. Required: ${specifier}`)
+          })
+
+          for (const [key, value] of Object.entries(ctx)) {
+            if (key === "helpers") {
+              // Can't copy the native helpers into the isolate. We just ignore them as they are handled properly from the helpersSource
+              continue
+            }
+            global.setSync(key, value)
+          }
+
+          bbCtx.isolateRefs = { jsContext, jsIsolate, helpersModule }
+        }
+
+        let { jsIsolate, jsContext, helpersModule } = bbCtx.isolateRefs!
+
+        const perRequestLimit = env.JS_PER_REQUEST_TIME_LIMIT_MS
+        if (perRequestLimit) {
+          const cpuMs = Number(jsIsolate.cpuTime) / 1e6
+          if (cpuMs > perRequestLimit) {
+            throw new ExecutionTimeoutError(
+              `CPU time limit exceeded (${cpuMs}ms > ${perRequestLimit}ms)`
+            )
+          }
+        }
+
+        const script = jsIsolate.compileModuleSync(
+          `import helpers from "compiled_module";${js};cb(run());`,
+          {}
         )
 
-        helpersModule.instantiateSync(jsContext, specifier => {
-          if (specifier === "crypto") {
-            return cryptoModule
+        script.instantiateSync(jsContext, specifier => {
+          if (specifier === "compiled_module") {
+            return helpersModule
           }
-          throw new Error(`No imports allowed. Required: ${specifier}`)
+
+          throw new Error(`"${specifier}" import not allowed`)
         })
 
-        for (const [key, value] of Object.entries(ctx)) {
-          if (key === "helpers") {
-            // Can't copy the native helpers into the isolate. We just ignore them as they are handled properly from the helpersSource
-            continue
-          }
-          global.setSync(key, value)
-        }
+        let result
+        jsContext.global.setSync(
+          "cb",
+          new ivm.Callback((value: any) => {
+            result = value
+          })
+        )
 
-        bbCtx.isolateRefs = { jsContext, jsIsolate, helpersModule }
-      }
-
-      let { jsIsolate, jsContext, helpersModule } = bbCtx.isolateRefs!
-
-      const perRequestLimit = env.JS_PER_REQUEST_TIME_LIMIT_MS
-      if (perRequestLimit) {
-        const cpuMs = Number(jsIsolate.cpuTime) / 1e6
-        if (cpuMs > perRequestLimit) {
-          throw new ExecutionTimeoutError(
-            `CPU time limit exceeded (${cpuMs}ms > ${perRequestLimit}ms)`
-          )
-        }
-      }
-
-      const script = jsIsolate.compileModuleSync(
-        `import helpers from "compiled_module";${js};cb(run());`,
-        {}
-      )
-
-      script.instantiateSync(jsContext, specifier => {
-        if (specifier === "compiled_module") {
-          return helpersModule
-        }
-
-        throw new Error(`"${specifier}" import not allowed`)
-      })
-
-      let result
-      jsContext.global.setSync(
-        "cb",
-        new ivm.Callback((value: any) => {
-          result = value
+        script.evaluateSync({
+          timeout: env.JS_PER_EXECUTION_TIME_LIMIT_MS,
         })
-      )
 
-      script.evaluateSync({
-        timeout: env.JS_PER_EXECUTION_TIME_LIMIT_MS,
-      })
+        return result
+      } catch (error: any) {
+        if (error.message === "Script execution timed out.") {
+          throw new JsErrorTimeout()
+        }
 
-      return result
+        throw error
+      }
     })
   })
 }
diff --git a/packages/string-templates/src/errors.js b/packages/string-templates/src/errors.js
new file mode 100644
index 0000000000..e0dcc3de1c
--- /dev/null
+++ b/packages/string-templates/src/errors.js
@@ -0,0 +1,11 @@
+class JsErrorTimeout extends Error {
+  code = "ERR_SCRIPT_EXECUTION_TIMEOUT"
+
+  constructor() {
+    super()
+  }
+}
+
+module.exports = {
+  JsErrorTimeout,
+}
diff --git a/packages/string-templates/src/index.cjs b/packages/string-templates/src/index.cjs
index aedb7fc052..b6475e42cd 100644
--- a/packages/string-templates/src/index.cjs
+++ b/packages/string-templates/src/index.cjs
@@ -35,3 +35,8 @@ if (!process.env.NO_JS) {
     return vm.run(js)
   })
 }
+
+const errors = require("./errors")
+for (const error in errors) {
+  module.exports[error] = errors[error]
+}
diff --git a/packages/string-templates/src/index.js b/packages/string-templates/src/index.js
index 63da7fde4d..8e28956f75 100644
--- a/packages/string-templates/src/index.js
+++ b/packages/string-templates/src/index.js
@@ -394,3 +394,8 @@ module.exports.convertToJS = hbs => {
 }
 
 module.exports.FIND_ANY_HBS_REGEX = FIND_ANY_HBS_REGEX
+
+const errors = require("./errors")
+for (const error in errors) {
+  module.exports[error] = errors[error]
+}
diff --git a/packages/string-templates/src/index.mjs b/packages/string-templates/src/index.mjs
index 43cda8183f..925eda3695 100644
--- a/packages/string-templates/src/index.mjs
+++ b/packages/string-templates/src/index.mjs
@@ -37,3 +37,5 @@ if (process && !process.env.NO_JS) {
     return vm.runInNewContext(js, context, { timeout: 1000 })
   })
 }
+
+export * from "./errors.js"