Merge pull request alan-turing-institute#2231 from alan-turing-instit…

…ute/ansi_logfile

Remove ANSI escape sequences from logfile

data_safe_haven/logging/plain_file_handler.py

@@ -16,16 +16,23 @@ def __init__(self, *args: Any, **kwargs: Any):
         super().__init__(*args, **kwargs)
 
     @staticmethod
-    def strip_formatting(input_string: str) -> str:
+    def strip_rich_formatting(input_string: str) -> str:
         """Strip console markup formatting from a string"""
         text = Text.from_markup(input_string)
         text.spans = []
         return str(text)
 
+    @staticmethod
+    def strip_ansi_escapes(input_string: str) -> str:
+        """Strip ANSI escape sequences from a string"""
+        text = Text.from_ansi(input_string)
+        text.spans = []
+        return str(text)
+
     def emit(self, record: logging.LogRecord) -> None:
         """Emit a record without formatting"""
         if isinstance(record.msg, Text):
             # Convert rich.text.Text objects to strings
             record.msg = str(record.msg)
-        record.msg = self.strip_formatting(record.msg)
+        record.msg = self.strip_ansi_escapes(self.strip_rich_formatting(record.msg))
         super().emit(record)

tests/logging/test_plain_file_handler.py

@@ -1,6 +1,15 @@
+import pytest
+
 from data_safe_haven.logging.plain_file_handler import PlainFileHandler
 
 
 class TestPlainFileHandler:
-    def test_strip_formatting(self):
-        assert PlainFileHandler.strip_formatting("[green]hello[/]") == "hello"
+    def test_strip_rich_formatting(self):
+        assert PlainFileHandler.strip_rich_formatting("[green]Hello[/]") == "Hello"
+
+    @pytest.mark.parametrize("escape", ["\033", "\x1B", "\u001b", "\x1B"])
+    def test_strip_ansi_escapes(self, escape):
+        assert (
+            PlainFileHandler.strip_ansi_escapes(f"{escape}[31;1;4mHello{escape}[0m")
+            == "Hello"
+        )