test: add test case for missing branch

- The case of id is string, flags is number
- The case of flags is not 0

PR-URL: #17418
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>

test/parallel/test-crypto-engine.js

@@ -5,6 +5,7 @@ if (!common.hasCrypto)
   common.skip('missing crypto');
 
 const crypto = require('crypto');
+const invalidEngineName = 'xxx';
 
 common.expectsError(
   () => crypto.setEngine(true),
@@ -21,3 +22,19 @@ common.expectsError(
     type: TypeError,
     message: 'The "flags" argument must be of type number'
   });
+
+common.expectsError(
+  () => crypto.setEngine(invalidEngineName),
+  {
+    code: 'ERR_CRYPTO_ENGINE_UNKNOWN',
+    type: Error,
+    message: `Engine "${invalidEngineName}" was not found`
+  });
+
+common.expectsError(
+  () => crypto.setEngine(invalidEngineName, crypto.constants.ENGINE_METHOD_RSA),
+  {
+    code: 'ERR_CRYPTO_ENGINE_UNKNOWN',
+    type: Error,
+    message: `Engine "${invalidEngineName}" was not found`
+  });