Fix serialization error

package.json

@@ -28,6 +28,7 @@
     "@semantic-release/git": "10.0.1",
     "@semantic-release/npm": "9.0.1",
     "@semantic-release/release-notes-generator": "10.0.3",
+    "@types/lodash": "4.17.0",
     "@types/node": "18.7.14",
     "@types/object-hash": "2.2.1",
     "@types/pg": "8.6.5",
@@ -46,6 +47,7 @@
   "dependencies": {
     "async-mutex": "0.4.0",
     "birpc": "0.2.17",
+    "lodash": "4.17.21",
     "nanoid": "4.0.0",
     "object-hash": "3.0.0",
     "pg": "8.8.0"

src/index.ts

@@ -18,6 +18,39 @@ import { once } from "node:events"
 import { createBirpc } from "birpc"
 import { SharedWorkerFunctions, TestWorkerFunctions } from "./lib/rpc"
 import { ExecResult } from "testcontainers"
+import isPlainObject from "lodash/isPlainObject"
+
+// https://stackoverflow.com/a/30580513
+const isSerializable = (obj: Record<any, any>): boolean => {
+  var isNestedSerializable
+  function isPlain(val: any) {
+    return (
+      typeof val === "undefined" ||
+      typeof val === "string" ||
+      typeof val === "boolean" ||
+      typeof val === "number" ||
+      Array.isArray(val) ||
+      isPlainObject(val)
+    )
+  }
+  if (!isPlain(obj)) {
+    return false
+  }
+  for (var property in obj) {
+    if (obj.hasOwnProperty(property)) {
+      if (!isPlain(obj[property])) {
+        return false
+      }
+      if (typeof obj[property] == "object") {
+        isNestedSerializable = isSerializable(obj[property])
+        if (!isNestedSerializable) {
+          return false
+        }
+      }
+    }
+  }
+  return true
+}
 
 const getWorker = async (
   initialData: InitialWorkerData,
@@ -132,6 +165,12 @@ export const getTestPostgresDatabaseFactory = <
 
           await teardownConnection(connectionDetails)
 
+          if (hookResult && !isSerializable(hookResult)) {
+            throw new TypeError(
+              "Return value of beforeTemplateIsBaked() hook could not be serialized. Make sure it returns only JSON-serializable values."
+            )
+          }
+
           return hookResult
         }
       },

yarn.lock

@@ -462,6 +462,11 @@
     "@types/docker-modem" "*"
     "@types/node" "*"
 
+"@types/lodash@4.17.0":
+  version "4.17.0"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.17.0.tgz#d774355e41f372d5350a4d0714abb48194a489c3"
+  integrity sha512-t7dhREVv6dbNj0q17X12j7yDG4bD/DHYX7o5/DbDxobP0HnGPgpRz2Ej77aL7TZT3DSw13fqUTj8J4mMnqa7WA==
+
 "@types/minimist@^1.2.0":
   version "1.2.2"
   resolved "https://registry.npmjs.org/@types/minimist/-/minimist-1.2.2.tgz"
@@ -2893,9 +2898,9 @@ lodash.uniqby@^4.7.0:
   resolved "https://registry.npmjs.org/lodash.uniqby/-/lodash.uniqby-4.7.0.tgz"
   integrity sha512-e/zcLx6CSbmaEgFHCA7BnoQKyCtKMxnuWrJygbwPs/AIn+IMKl66L8/s+wBUn5LRw2pZx3bUHibiV1b6aTWIww==
 
-lodash@^4.17.15, lodash@^4.17.21, lodash@^4.17.4:
+lodash@4.17.21, lodash@^4.17.15, lodash@^4.17.21, lodash@^4.17.4:
   version "4.17.21"
-  resolved "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
   integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 lru-cache@^6.0.0: