fix: throw explicit error when using unknown encrypter

Author: RomainLanz

src/encryption_manager.ts

@@ -58,6 +58,12 @@ export class EncryptionManager<KnownEncrypters extends Record<string, Encryption
       return cachedEncryption
     }
 
+    if (!Object.hasOwn(this.#config.list, encrypterToUse)) {
+      throw new RuntimeException(
+        `Cannot create encryption instance. Encryption "${String(encrypterToUse)}" is not defined in the config`
+      )
+    }
+
     const encrypterConfig = this.#config.list[encrypterToUse]
 
     /**

tests/encryption_manager.spec.ts

@@ -71,6 +71,21 @@ test.group('Encryption manager', () => {
     )
   })
 
+  test('fail when encrypter is not configured', ({ assert }) => {
+    const manager = new EncryptionManager({
+      default: 'legacy',
+      list: {
+        legacy: chacha20poly1305({ id: 'nova', keys: [SECRET] }),
+      },
+    })
+
+    assert.throws(
+      // @ts-expect-error testing runtime guard
+      () => manager.use('missing'),
+      'Cannot create encryption instance. Encryption "missing" is not defined in the config'
+    )
+  })
+
   test('use message verifier', ({ assert }) => {
     const manager = new EncryptionManager({
       default: 'legacy',