tests: Add rudimentary integration test for Unix domain socket functionality

electrum/tests/regtest.py

@@ -34,6 +34,13 @@ class TestLightning(unittest.TestCase):
             self.run_shell(['stop', agent])
 
 
+class TestUnixSockets(TestLightning):
+    agents = []
+
+    def test_unixsockets(self):
+        self.run_shell(['unixsockets'])
+
+
 class TestLightningAB(TestLightning):
     agents = ['alice', 'bob']
 

electrum/tests/regtest/regtest.sh

@@ -356,3 +356,19 @@ if [[ $1 == "watchtower" ]]; then
     echo "watchtower publishes justice transaction"
     wait_until_spent $ctx_id 1  # alice's to_local gets punished immediately
 fi
+
+if [[ $1 == "unixsockets" ]]; then
+    # This looks different because it has to run the entire daemon
+    # Test domain socket behavior
+    ./run_electrum --regtest daemon -d --rpcsock=unix # Start daemon with unix domain socket
+    ./run_electrum --regtest stop # Errors if it can't connect
+    # Test custom socket path
+    f=$(mktemp --dry-run)
+    ./run_electrum --regtest daemon -d --rpcsock=unix --rpcsockpath=$f
+    [ -S $f ] # filename exists and is socket
+    ./run_electrum --regtest stop
+    rm $f # clean up
+    # Test for regressions in the ordinary TCP functionality.
+    ./run_electrum --regtest daemon -d --rpcsock=tcp
+    ./run_electrum --regtest stop
+fi