Merge bitcoin/bitcoin#27884: test: Use TestNode datadir_path or chain_path where possible

aaaa3aefbd test: Use TestNode *_path properties where possible (MarcoFalke)
dddd89962b test: Allow pathlib.Path as RPC argument via authproxy (MarcoFalke)
fa41614a0a scripted-diff: Use wallets_path and chain_path where possible (MarcoFalke)
fa493fadfb test: Use wallet_dir lambda in wallet_multiwallet test where possible (MarcoFalke)

Pull request description:

  It seems inconsistent, fragile and verbose to:

  * Call `get_datadir_path` to recreate the path that already exists as field in TestNode
  * Call `os.path.join` with the hardcoded chain name or `self.chain` to recreate the TestNode `chain_path` property
  * Sometimes even use the hardcoded node dir name (`"node0"`)

  Fix all issues by using the TestNode properties.

ACKs for top commit:
  willcl-ark:
    re-ACK aaaa3aefbd
  theStack:
    Code-review ACK aaaa3aefbd 🌊

Tree-SHA512: e4720278085beb8164e1fe6c1aa18f601558a9263494ce69a83764c1487007de63ebb51d1b1151862dc4d5b49ded6162a5c1553cd30ea1c28627d447db4d8e72

test/functional/test_framework/authproxy.py

@@ -39,6 +39,7 @@ from http import HTTPStatus
 import http.client
 import json
 import logging
+import pathlib
 import socket
 import time
 import urllib.parse
@@ -62,6 +63,8 @@ class JSONRPCException(Exception):
 def EncodeDecimal(o):
     if isinstance(o, decimal.Decimal):
         return str(o)
+    if isinstance(o, pathlib.Path):
+        return str(o)
     raise TypeError(repr(o) + " is not JSON serializable")
 
 class AuthServiceProxy():

test/functional/test_framework/test_node.py

@@ -22,7 +22,10 @@ import shlex
 import sys
 from pathlib import Path
 
-from .authproxy import JSONRPCException
+from .authproxy import (
+    JSONRPCException,
+    EncodeDecimal,
+)
 from .descriptors import descsum_create
 from .p2p import P2P_SUBVERSION
 from .util import (
@@ -35,7 +38,6 @@ from .util import (
     rpc_url,
     wait_until_helper,
     p2p_port,
-    EncodeDecimal,
 )
 
 BITCOIND_PROC_WAIT_TIMEOUT = 60
@@ -405,14 +407,22 @@ class TestNode():
         with open(self.bitcoinconf, 'w', encoding='utf8') as conf:
             conf.write(conf_data)
 
+    @property
+    def datadir_path(self) -> Path:
+        return Path(self.datadir)
+
     @property
     def chain_path(self) -> Path:
-        return Path(self.datadir) / self.chain
+        return self.datadir_path / self.chain
 
     @property
     def debug_log_path(self) -> Path:
         return self.chain_path / 'debug.log'
 
+    @property
+    def wallets_path(self) -> Path:
+        return self.chain_path / "wallets"
+
     def debug_log_bytes(self) -> int:
         with open(self.debug_log_path, encoding='utf-8') as dl:
             dl.seek(0, 2)

test/functional/test_framework/util.py

@@ -211,12 +211,6 @@ def check_json_precision():
         raise RuntimeError("JSON encode/decode loses precision")
 
 
-def EncodeDecimal(o):
-    if isinstance(o, Decimal):
-        return str(o)
-    raise TypeError(repr(o) + " is not JSON serializable")
-
-
 def count_bytes(hex_string):
     return len(bytearray.fromhex(hex_string))