Refactor out shared script checker util

Needed by system_tests, so need to be in src/

Author: Tom-Willemsen

src/genie_python/testing_utils/__init__.py

@@ -0,0 +1,4 @@
+"""
+This private module exists to allow testing utility code to be shared between genie_python's
+unit tests, and the external system tests.
+"""

src/genie_python/testing_utils/script_checker.py

@@ -0,0 +1,64 @@
+import os
+import tempfile
+from types import TracebackType
+
+from genie_python.genie_script_checker import ScriptChecker
+
+
+def write_to_temp_file(
+    message: str, suffix: str = "", dir: str = ""
+) -> tempfile.NamedTemporaryFile:
+    """
+    write to temporary file for test check_script
+
+    Args:
+        message: message to write to file
+        suffix: filename suffix
+        dir: directory to write into
+
+    Returns:
+        temporary file
+    """
+    temp_file = tempfile.NamedTemporaryFile(delete=False, suffix=suffix, dir=dir)
+    for line in message:
+        temp_file.write(line.encode("utf-8"))
+    temp_file.close()
+    return temp_file
+
+
+class CreateTempScriptAndReturnErrors:
+    def __init__(
+        self,
+        script_checker: ScriptChecker,
+        machine: str,
+        script: str,
+        warnings_as_error: bool = True,
+        no_pyright: bool = False,
+        no_pylint: bool = False,
+        dir: str = "",
+    ) -> None:
+        self.script = script
+        self.machine = machine
+        self.dir = dir
+        self.warnings_as_error = warnings_as_error
+        self.no_pyright = no_pyright
+        self.no_pylint = no_pylint
+        self.script_checker = script_checker
+
+    def __enter__(self) -> list[str]:
+        self.temp_script_file = write_to_temp_file(self.script, dir=self.dir)
+        return self.script_checker.check_script(
+            self.temp_script_file.name,
+            self.machine,
+            warnings_as_error=self.warnings_as_error,
+            no_pyright=self.no_pyright,
+            no_pylint=self.no_pylint,
+        )
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_value: BaseException | None,
+        exc_traceback: TracebackType,
+    ) -> None:
+        os.unlink(self.temp_script_file.name)