test: add blocks_key_path

Adds a convenience function to TestNode
to provide the path to the blocks xor key.
Updates util and feature_blocksxor to use it.

Author: tdb3

test/functional/feature_blocksxor.py

@@ -54,7 +54,7 @@ def run_test(self):
             match=ErrorMatch.PARTIAL_REGEX)
 
         self.log.info("Delete XOR key, restart node with '-blocksxor=0', check blk*.dat/rev*.dat file integrity")
-        os.remove(node.blocks_path / 'xor.dat')
+        os.remove(node.blocks_key_path)
         self.start_node(0, extra_args=['-blocksxor=0'])
         # checklevel=2 -> verify block validity + undo data
         # nblocks=0    -> verify all blocks

test/functional/test_framework/test_node.py

@@ -465,6 +465,10 @@ def debug_log_path(self) -> Path:
     def blocks_path(self) -> Path:
         return self.chain_path / "blocks"
 
+    @property
+    def blocks_key_path(self) -> Path:
+        return self.blocks_path / "xor.dat"
+
     @property
     def wallets_path(self) -> Path:
         return self.chain_path / "wallets"

test/functional/test_framework/util.py

@@ -516,7 +516,7 @@ def check_node_connections(*, node, num_in, num_out):
 
 
 def read_xor_key(*, node):
-    with open(node.blocks_path / "xor.dat", "rb") as xor_f:
+    with open(node.blocks_key_path, "rb") as xor_f:
         NUM_XOR_BYTES = 8 # From InitBlocksdirXorKey::xor_key.size()
         return xor_f.read(NUM_XOR_BYTES)