Runtime Server: Pass error through properly (sst#938)

Author: thdxr

.eslintrc.json

@@ -48,7 +48,8 @@
       "rules": {
         "@typescript-eslint/explicit-module-boundary-types": "off",
         "@typescript-eslint/no-non-null-assertion": "off",
-        "@typescript-eslint/no-explicit-any": "off"
+        "@typescript-eslint/no-explicit-any": "off",
+        "@typescript-eslint/ban-ts-comment": "off"
       }
     }
   ]

packages/core/src/runtime/error.ts

@@ -0,0 +1,79 @@
+// @ts-nocheck
+
+// Serialize error
+// https://github.com/sindresorhus/serialize-error/blob/master/index.js
+const commonProperties = [
+  { property: "name", enumerable: false },
+  { property: "message", enumerable: false },
+  { property: "stack", enumerable: false },
+  { property: "code", enumerable: true },
+];
+
+const destroyCircular = ({ from, seen, to_, forceEnumerable }) => {
+  const to = to_ || (Array.isArray(from) ? [] : {});
+
+  seen.push(from);
+
+  for (const [key, value] of Object.entries(from)) {
+    if (typeof value === "function") {
+      continue;
+    }
+
+    if (!value || typeof value !== "object") {
+      to[key] = value;
+      continue;
+    }
+
+    if (!seen.includes(from[key])) {
+      to[key] = destroyCircular({
+        from: from[key],
+        seen: seen.slice(),
+        forceEnumerable,
+      });
+      continue;
+    }
+
+    to[key] = "[Circular]";
+  }
+
+  for (const { property, enumerable } of commonProperties) {
+    if (typeof from[property] === "string") {
+      Object.defineProperty(to, property, {
+        value: from[property],
+        enumerable: forceEnumerable ? true : enumerable,
+        configurable: true,
+        writable: true,
+      });
+    }
+  }
+
+  return to;
+};
+
+export const serializeError = (value) => {
+  if (typeof value === "object" && value !== null) {
+    return destroyCircular({ from: value, seen: [], forceEnumerable: true });
+  }
+
+  // People sometimes throw things besides Error objects…
+  if (typeof value === "function") {
+    // `JSON.stringify()` discards functions. We do too, unless a function is thrown directly.
+    return `[Function: ${value.name || "anonymous"}]`;
+  }
+
+  return value;
+};
+
+export const deserializeError = (value) => {
+  if (value instanceof Error) {
+    return value;
+  }
+
+  if (typeof value === "object" && value !== null && !Array.isArray(value)) {
+    const newError = new Error();
+    destroyCircular({ from: value, seen: [], to_: newError });
+    return newError;
+  }
+
+  return value;
+};

packages/core/src/runtime/server.ts

@@ -4,6 +4,7 @@ import path from "path";
 import { ChildProcess } from "child_process";
 import { getChildLogger } from "../logger";
 import crypto from "crypto";
+import { serializeError } from "./error";
 
 const logger = getChildLogger("client");
 
@@ -36,7 +37,8 @@ type ResponseTimeout = {
 };
 type ResponseFailure = {
   type: "failure";
-  error: any;
+  error: Error;
+  rawError: any;
 };
 
 type Response = ResponseSuccess | ResponseFailure | ResponseTimeout;
@@ -119,9 +121,14 @@ export class Server {
           req.params.awsRequestId,
           req.params.fun
         );
+        const err = new Error();
+        err.name = req.body.errorType;
+        err.message = req.body.errorMessage;
+        delete err.stack;
         this.response(req.params.fun, req.params.awsRequestId, {
           type: "failure",
-          error: req.body,
+          error: serializeError(err),
+          rawError: req.body,
         });
         res.status(202).send();
       }