Move shared fixtures and constants to files

tests/interop/conftest.py

@@ -0,0 +1,24 @@
+import sys
+
+import pexpect
+import pytest
+
+
+@pytest.fixture
+def proc_factory():
+    procs = []
+
+    def call_proc(cmd, args, logfile=None, encoding=None):
+        if logfile is None:
+            logfile = sys.stdout
+        if encoding is None:
+            encoding = "utf-8"
+        proc = pexpect.spawn(cmd, args, logfile=logfile, encoding=encoding)
+        procs.append(proc)
+        return proc
+
+    try:
+        yield call_proc
+    finally:
+        for proc in procs:
+            proc.close()