test: add better test for luhn algo

Benricheson101 · Nov 12, 2024 · fad5cd7 · fad5cd7
1 parent 11d6b8e
commit fad5cd7
Showing 1 changed file with 15 additions and 2 deletions.
diff --git a/lib/misc/luhnCheck.test.ts b/lib/misc/luhnCheck.test.ts
@@ -1,6 +1,11 @@
-import {strictEqual} from 'node:assert';
+import assert, {strictEqual} from 'node:assert';
 import {describe, it} from 'node:test';
-import {computeLuhnCheckDigit, isValidLuhn, toLuhn} from './luhnCheck';
+import {
+  computeLuhnCheckDigit,
+  fromLuhn,
+  isValidLuhn,
+  toLuhn,
+} from './luhnCheck';
 
 describe('misc/luhnCheck', () => {
   it('should correctly calculate the luhn check digit', () => {
@@ -15,4 +20,12 @@ describe('misc/luhnCheck', () => {
     strictEqual(isValidLuhn(17893729974), true);
     strictEqual(isValidLuhn(17893729972), false);
   });
+
+  it('should correctly add and verify many check digits', () => {
+    for (let i = 0; i < 100_000; i++) {
+      const signed = toLuhn(i);
+      assert(isValidLuhn(signed));
+      strictEqual(fromLuhn(signed), i);
+    }
+  });
 });