RAHHH

backend/lib/python3.12/site-packages/twisted/logger/test/test_util.py

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+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Test cases for L{twisted.logger._util}.
+"""
+
+from zope.interface import implementer
+
+from twisted.trial import unittest
+from .._interfaces import ILogObserver, LogEvent
+from .._observer import LogPublisher
+from .._util import formatTrace
+
+
+class UtilTests(unittest.TestCase):
+    """
+    Utility tests.
+    """
+
+    def test_trace(self) -> None:
+        """
+        Tracing keeps track of forwarding done by the publisher.
+        """
+        publisher = LogPublisher()
+
+        event: LogEvent = dict(log_trace=[])
+
+        @implementer(ILogObserver)
+        def o1(e: LogEvent) -> None:
+            pass
+
+        @implementer(ILogObserver)
+        def o2(e: LogEvent) -> None:
+            self.assertIs(e, event)
+            self.assertEqual(
+                e["log_trace"],
+                [
+                    (publisher, o1),
+                    (publisher, o2),
+                    # Event hasn't been sent to o3 yet
+                ],
+            )
+
+        @implementer(ILogObserver)
+        def o3(e: LogEvent) -> None:
+            self.assertIs(e, event)
+            self.assertEqual(
+                e["log_trace"],
+                [
+                    (publisher, o1),
+                    (publisher, o2),
+                    (publisher, o3),
+                ],
+            )
+
+        publisher.addObserver(o1)
+        publisher.addObserver(o2)
+        publisher.addObserver(o3)
+        publisher(event)
+
+    def test_formatTrace(self) -> None:
+        """
+        Format trace as string.
+        """
+        event: LogEvent = dict(log_trace=[])
+
+        @implementer(ILogObserver)
+        def o1(e: LogEvent) -> None:
+            pass
+
+        @implementer(ILogObserver)
+        def o2(e: LogEvent) -> None:
+            pass
+
+        @implementer(ILogObserver)
+        def o3(e: LogEvent) -> None:
+            pass
+
+        @implementer(ILogObserver)
+        def o4(e: LogEvent) -> None:
+            pass
+
+        @implementer(ILogObserver)
+        def o5(e: LogEvent) -> None:
+            pass
+
+        o1.name = "root/o1"
+        o2.name = "root/p1/o2"
+        o3.name = "root/p1/o3"
+        o4.name = "root/p1/p2/o4"
+        o5.name = "root/o5"
+
+        expectedTrace: str  # populated below
+
+        @implementer(ILogObserver)
+        def testObserver(e: LogEvent) -> None:
+            self.assertIs(e, event)
+            trace = formatTrace(e["log_trace"])
+            self.assertEqual(trace, expectedTrace)
+
+        oTest = testObserver
+
+        p2 = LogPublisher(o4)
+        p1 = LogPublisher(o2, o3, p2)
+
+        p2.name = "root/p1/p2/"  # type: ignore[attr-defined]
+        p1.name = "root/p1/"  # type: ignore[attr-defined]
+
+        root = LogPublisher(o1, p1, o5, oTest)
+        root.name = "root/"  # type: ignore[attr-defined]
+        expectedTraceTemplate = (
+            "{root} ({root.name})\n"
+            "  -> {o1} ({o1.name})\n"
+            "  -> {p1} ({p1.name})\n"
+            "    -> {o2} ({o2.name})\n"
+            "    -> {o3} ({o3.name})\n"
+            "    -> {p2} ({p2.name})\n"
+            "      -> {o4} ({o4.name})\n"
+            "  -> {o5} ({o5.name})\n"
+            "  -> {oTest}\n"
+        )
+
+        # Mypy rightly complains that we're pulling some Shenanigans with all
+        # these 'name' attributes above (LogPublisher does not have any such
+        # attribute, neither does FunctionType) so we split up the 'format'
+        # call so it can't see the attributes being formatted.
+        expectedTrace = expectedTraceTemplate.format(
+            root=root,
+            o1=o1,
+            o2=o2,
+            o3=o3,
+            o4=o4,
+            o5=o5,
+            p1=p1,
+            p2=p2,
+            oTest=oTest,
+        )
+        root(event)