test: Split tool_wallet.py test into subtests

as per Marco Falke review suggestion.

test/functional/tool_wallet.py

@@ -37,7 +37,7 @@ class ToolWalletTest(BitcoinTestFramework):
         assert_equal(stderr, '')
         assert_equal(stdout, output)
 
-    def run_test(self):
+    def test_invalid_tool_commands_and_args(self):
         self.log.info('Testing that various invalid commands raise with specific error messages')
         self.assert_raises_tool_error('Invalid command: foo', 'foo')
         # `bitcoin-wallet help` raises an error. Use `bitcoin-wallet -help`.
@@ -47,6 +47,7 @@ class ToolWalletTest(BitcoinTestFramework):
         self.assert_raises_tool_error('Error loading wallet.dat. Is wallet being used by other process?', '-wallet=wallet.dat', 'info')
         self.assert_raises_tool_error('Error: no wallet file at nonexistent.dat', '-wallet=nonexistent.dat', 'info')
 
+    def test_tool_wallet_info(self):
         # Stop the node to close the wallet to call the info command.
         self.stop_node(0)
         self.log.info('Calling wallet tool info, testing output')
@@ -61,7 +62,11 @@ class ToolWalletTest(BitcoinTestFramework):
         ''')
         self.assert_tool_output(out, '-wallet=wallet.dat', 'info')
 
-        # Mutate wallet to verify info command output changes accordingly.
+    def test_tool_wallet_info_after_transaction(self):
+        """
+        Mutate the wallet with a transaction to verify that the info command
+        output changes accordingly.
+        """
         self.start_node(0)
         self.log.info('Generating transaction to mutate wallet')
         self.nodes[0].generate(1)
@@ -79,6 +84,7 @@ class ToolWalletTest(BitcoinTestFramework):
         ''')
         self.assert_tool_output(out, '-wallet=wallet.dat', 'info')
 
+    def test_tool_wallet_create_on_existing_wallet(self):
         self.log.info('Calling wallet tool create on an existing wallet, testing output')
         out = textwrap.dedent('''\
             Topping up keypool...
@@ -92,6 +98,7 @@ class ToolWalletTest(BitcoinTestFramework):
         ''')
         self.assert_tool_output(out, '-wallet=foo', 'create')
 
+    def test_getwalletinfo_on_different_wallet(self):
         self.log.info('Starting node with arg -wallet=foo')
         self.start_node(0, ['-wallet=foo'])
 
@@ -104,5 +111,14 @@ class ToolWalletTest(BitcoinTestFramework):
         assert_equal(1000, out['keypoolsize_hd_internal'])
         assert_equal(True, 'hdseedid' in out)
 
+    def run_test(self):
+        self.test_invalid_tool_commands_and_args()
+        # Warning: The following tests are order-dependent.
+        self.test_tool_wallet_info()
+        self.test_tool_wallet_info_after_transaction()
+        self.test_tool_wallet_create_on_existing_wallet()
+        self.test_getwalletinfo_on_different_wallet()
+
+
 if __name__ == '__main__':
     ToolWalletTest().main()