Add custom logfmt parser based off python-logfmt

This specifically doesn't add quotes where they're not necessary

catfish/utils/logfmt.py

@@ -0,0 +1,31 @@
+# Adapted from https://github.com/jkakar/logfmt-python/blob/master/logfmt/formatter.py
+
+from typing import Any, Dict
+
+CHARS_TO_ESCAPE = [" ", "=", "\\", '"', "'"]
+
+
+def bool_to_str(i: bool) -> str:
+    return str(i).lower()
+
+
+def escape_value(value: str):
+    value = value.replace('"', '\\"')
+    if any([char in value for char in CHARS_TO_ESCAPE]):
+        value = '"{}"'.format(value)
+    return value
+
+
+def logfmt(data: Dict[str, Any]):
+    out = []
+    for k, v in data.items():
+        if not k.isidentifier():
+            continue
+        if v is None:
+            v = ""
+        elif isinstance(v, bool):
+            v = bool_to_str(v)
+        elif isinstance(v, str):
+            v = escape_value(v)
+        out.append("{}={}".format(k, v))
+    return " ".join(out)

tests/test_utils/test_logfmt.py

@@ -0,0 +1,58 @@
+from catfish.utils.logfmt import logfmt
+from tests import BaseTestCase
+
+
+class LogFmtTestCase(BaseTestCase):
+    def test_simple_logfmt(self):
+        self.assertEqual(
+            logfmt({"key1": "value1", "key2": "value2"}), "key1=value1 key2=value2"
+        )
+
+    def test_quotes_space(self):
+        self.assertEqual(
+            logfmt({"key1": "value1 valuea", "key2": "value2 valueb"}),
+            'key1="value1 valuea" key2="value2 valueb"',
+        )
+
+    def test_quotes_equals(self):
+        self.assertEqual(
+            logfmt({"key1": "value1=valuea", "key2": "value2=valueb"}),
+            'key1="value1=valuea" key2="value2=valueb"',
+        )
+
+    def test_quotes_quotes(self):
+        self.assertEqual(
+            logfmt({"key1": '"value1"', "key2": '"value2"'}),
+            'key1="\\"value1\\"" key2="\\"value2\\""',
+        )
+        self.assertEqual(
+            logfmt({"key1": "'value1'", "key2": "'value2'"}),
+            "key1=\"'value1'\" key2=\"'value2'\"",
+        )
+
+    def test_empty(self):
+        self.assertEqual(logfmt({}), "")
+
+    def test_boolean_values(self):
+        self.assertEqual(logfmt({"key1": True, "key2": False}), "key1=true key2=false")
+
+    def test_none_values(self):
+        self.assertEqual(logfmt({"key1": None, "key2": None}), "key1= key2=")
+
+    def test_numbers(self):
+        self.assertEqual(
+            logfmt({"key1": 12345, "key2": -12345}), "key1=12345 key2=-12345"
+        )
+        self.assertEqual(
+            logfmt({"key1": "12345", "key2": "-12345"}), "key1=12345 key2=-12345"
+        )
+
+    def test_float(self):
+        self.assertEqual(
+            logfmt({"key1": 12345.67, "key2": -12345.67}),
+            "key1=12345.67 key2=-12345.67",
+        )
+        self.assertEqual(
+            logfmt({"key1": "12345.67", "key2": "-12345.67"}),
+            "key1=12345.67 key2=-12345.67",
+        )