fix: fix original dict being logged in nested keys

Resolves #39

Author: spaceone

src/logfmter/formatter.py

@@ -236,6 +236,9 @@ def format(self, record: logging.LogRecord) -> str:
             else:
                 continue
 
+            if isinstance(value, dict):
+                continue
+
             tokens.append("{}={}".format(key, self.format_value(value)))
 
         formatted_params = self.format_params(params)

tests/test_formatter.py

@@ -311,6 +311,52 @@ def test_extra_keys(record):
     )
 
 
+@pytest.mark.parametrize(
+    "record,expected",
+    [
+        (
+            {
+                "msg": {"msg": "alpha"},
+                "levelname": "INFO",
+                "foo": {"bar": "baz", "blub": "blah"},
+            },
+            "at=INFO msg=alpha foo.bar=baz foo.blub=blah",
+        ),
+        (
+            {
+                "msg": "alpha",
+                "levelname": "INFO",
+                "foo": {"bar": "baz", "blub": "blah"},
+                "foo.bar": "XXX",
+            },
+            "at=INFO msg=alpha foo.bar=XXX foo.blub=blah",
+        ),
+        (
+            {
+                "msg": {"msg": "alpha", "foo": {"bar": "baz", "blub": "blah"}},
+                "levelname": "INFO",
+            },
+            "at=INFO msg=alpha foo.bar=baz foo.blub=blah",
+        ),
+        (
+            {
+                "msg": {
+                    "msg": "alpha",
+                    "foo": {"bar": "baz", "blub": "blah"},
+                    "foo.bar": "XXX",
+                },
+                "levelname": "INFO",
+            },
+            "at=INFO msg=alpha foo.bar=XXX foo.blub=blah",
+        ),
+    ],
+)
+def test_format_nested_keys(record, expected):
+    record = logging.makeLogRecord(record)
+    assert Logfmter(keys=["at", "foo"]).format(record) == expected
+    assert Logfmter(keys=["at"]).format(record) == expected
+
+
 @pytest.mark.external
 @pytest.mark.parametrize(
     "value",