infra: enable strictNullChecks in tsconfig (#2435)

1 files changed, 9 insertions, 1 deletions

diff --git a/src/modules/commerce/index.ts b/src/modules/commerce/index.ts
index 1be3fcb2..425bc848 100644
--- a/src/modules/commerce/index.ts
+++ b/src/modules/commerce/index.ts
@@ -1,3 +1,4 @@
+import { FakerError } from '../../errors/faker-error';
 import { deprecated } from '../../internal/deprecated';
 import { ModuleBase } from '../../internal/module-base';
 
@@ -401,7 +402,14 @@ export class CommerceModule extends ModuleBase {
 
     const registrantLength = groupRules.find(
       ([rangeMaximum]) => elementValue <= rangeMaximum
-    )[1];
+    )?.[1];
+
+    if (!registrantLength) {
+      // This can only happen if the ISBN_LENGTH_RULES are corrupted
+      throw new FakerError(
+        `Unable to find a registrant length for the group ${group}`
+      );
+    }
 
     const registrant = element.slice(0, registrantLength);
     const publication = element.slice(registrantLength);