preserve contextvars if necessary - closes #20

Author: wimglenn

.github/workflows/tests.yml

@@ -2,9 +2,9 @@ name: tests
 
 on:
   push:
-    branches: ["master"]
+    branches: ["main"]
   pull_request:
-    branches: ["master"]
+    branches: ["main"]
   workflow_dispatch:
 
 jobs:
@@ -14,17 +14,16 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["2.7", "3.10"]
+        python-version: ["2.7", "3.11"]
 
     steps:
-      - uses: "actions/checkout@v2"
-      - uses: "actions/setup-python@v2"
+      - uses: "actions/checkout@v3"
+      - uses: "actions/setup-python@v4"
         with:
           python-version: "${{ matrix.python-version }}"
       - name: "Install"
         run: |
           set -xe
-          python -VV
           python -m pip install --editable .
       - name: "Run tests for ${{ matrix.python-version }}"
         run: python -m pytest

pytest_structlog.py

@@ -2,8 +2,15 @@
 import pytest
 import structlog
 
+try:
+    from structlog.contextvars import merge_contextvars
+except ImportError:
+    # structolg < 20.1.0
+    # use a "missing" sentinel to avoid a NameError later on
+    merge_contextvars = object()
 
-__version__ = "0.5"
+
+__version__ = "0.6"
 
 
 class EventList(list):
@@ -73,14 +80,17 @@ def log(monkeypatch, request):
 
     # redirect logging to log capture
     cap = StructuredLogCapture()
+    new_processors = []
     for processor in original_processors:
         if isinstance(processor, structlog.stdlib.PositionalArgumentsFormatter):
             # if there was a positional argument formatter in there, keep it there
             # see https://github.com/wimglenn/pytest-structlog/issues/18
-            new_processors = [processor, cap.process]
-            break
-    else:
-        new_processors = [cap.process]
+            new_processors.append(processor)
+        elif processor is merge_contextvars:
+            # if merging contextvars, preserve
+            # see https://github.com/wimglenn/pytest-structlog/issues/20
+            new_processors.append(processor)
+    new_processors.append(cap.process)
     structlog.configure(processors=new_processors, cache_logger_on_first_use=False)
     cap.original_configure = configure = structlog.configure
     cap.configure_once = structlog.configure_once

setup.py

@@ -2,7 +2,7 @@
 
 setup(
     name="pytest-structlog",
-    version="0.5",
+    version="0.6",
     url="https://github.com/wimglenn/pytest-structlog",
     description="Structured logging assertions",
     long_description=open("README.rst").read(),

tests/test_issue18.py

@@ -21,7 +21,6 @@ def stdlib_configure():
         ],
         logger_factory=structlog.stdlib.LoggerFactory(),
         wrapper_class=structlog.stdlib.BoundLogger,
-        context_class=structlog.threadlocal.wrap_dict(dict),
     )
 
 

tests/test_issue20.py

@@ -0,0 +1,29 @@
+import pytest
+import structlog
+
+
+logger = structlog.get_logger()
+
+
+@pytest.fixture
+def issue20_setup():
+    structlog.configure(
+        processors=[
+            structlog.contextvars.merge_contextvars,
+            structlog.stdlib.filter_by_level,
+            structlog.stdlib.ProcessorFormatter.wrap_for_formatter,
+        ],
+        wrapper_class=structlog.stdlib.BoundLogger,
+        logger_factory=structlog.stdlib.LoggerFactory(),
+        context_class=dict,
+    )
+    yield
+    structlog.contextvars.clear_contextvars()
+
+
+def test_contextvar(issue20_setup, log):
+    structlog.contextvars.clear_contextvars()
+    logger.info("log1", log1var="value")
+    structlog.contextvars.bind_contextvars(contextvar="cv")
+    logger.info("log2", log2var="value")
+    assert log.has("log2", log2var="value", contextvar="cv")