test: add test coverage for "warnings" field in createwallet

and clarify the "warning" field behavior.

test/functional/wallet_createwallet.py

@@ -15,6 +15,10 @@ from test_framework.util import (
 )
 from test_framework.wallet_util import bytes_to_wif, generate_wif_key
 
+EMPTY_PASSPHRASE_MSG = "Empty string given as passphrase, wallet will not be encrypted."
+LEGACY_WALLET_MSG = "Wallet created successfully. The legacy wallet type is being deprecated and support for creating and opening legacy wallets will be removed in the future."
+
+
 class CreateWalletTest(BitcoinTestFramework):
     def add_options(self, parser):
         self.add_wallet_options(parser)
@@ -159,7 +163,9 @@ class CreateWalletTest(BitcoinTestFramework):
         assert_equal(walletinfo['keypoolsize_hd_internal'], keys)
         # Allow empty passphrase, but there should be a warning
         resp = self.nodes[0].createwallet(wallet_name='w7', disable_private_keys=False, blank=False, passphrase='')
-        assert 'Empty string given as passphrase, wallet will not be encrypted.' in resp['warning']
+        assert_equal(resp["warning"], EMPTY_PASSPHRASE_MSG if self.options.descriptors else f"{EMPTY_PASSPHRASE_MSG}\n{LEGACY_WALLET_MSG}")
+        assert_equal(resp["warnings"], [EMPTY_PASSPHRASE_MSG] if self.options.descriptors else [EMPTY_PASSPHRASE_MSG, LEGACY_WALLET_MSG])
+
         w7 = node.get_wallet_rpc('w7')
         assert_raises_rpc_error(-15, 'Error: running with an unencrypted wallet, but walletpassphrase was called.', w7.walletpassphrase, '', 60)
 
@@ -174,8 +180,19 @@ class CreateWalletTest(BitcoinTestFramework):
 
         if self.is_bdb_compiled():
             self.log.info("Test legacy wallet deprecation")
-            res = self.nodes[0].createwallet(wallet_name="legacy_w0", descriptors=False, passphrase=None)
-            assert_equal(res["warning"], "Wallet created successfully. The legacy wallet type is being deprecated and support for creating and opening legacy wallets will be removed in the future.")
+            result = self.nodes[0].createwallet(wallet_name="legacy_w0", descriptors=False, passphrase=None)
+            assert_equal(result, {
+                "name": "legacy_w0",
+                "warning": LEGACY_WALLET_MSG,
+                "warnings": [LEGACY_WALLET_MSG],
+            })
+            result = self.nodes[0].createwallet(wallet_name="legacy_w1", descriptors=False, passphrase="")
+            assert_equal(result, {
+                "name": "legacy_w1",
+                "warning": f"{EMPTY_PASSPHRASE_MSG}\n{LEGACY_WALLET_MSG}",
+                "warnings": [EMPTY_PASSPHRASE_MSG, LEGACY_WALLET_MSG],
+            })
+
 
 if __name__ == '__main__':
     CreateWalletTest().main()