feat: Add unittest coverage

tests/test_fronting_support.py

@@ -0,0 +1,66 @@
+import pathlib
+import sys
+import unittest
+
+
+ROOT = pathlib.Path(__file__).resolve().parents[1]
+SRC = ROOT / "src"
+if str(SRC) not in sys.path:
+    sys.path.insert(0, str(SRC))
+
+from core.constants import FRONT_SNI_POOL_GOOGLE
+from relay.fronting_support import (
+    build_sni_pool,
+    parse_content_range,
+    validate_range_response,
+)
+
+
+class BuildSniPoolTests(unittest.TestCase):
+    def test_uses_explicit_overrides_with_normalization_and_deduplication(self):
+        result = build_sni_pool(
+            "www.google.com",
+            [" Mail.Google.com ", "mail.google.com", "accounts.google.com."],
+        )
+        self.assertEqual(result, ["mail.google.com", "accounts.google.com"])
+
+    def test_google_front_domain_uses_google_pool(self):
+        result = build_sni_pool("www.google.com", None)
+        self.assertEqual(result, list(FRONT_SNI_POOL_GOOGLE))
+
+    def test_non_google_front_domain_falls_back_to_single_host(self):
+        self.assertEqual(build_sni_pool("cdn.example.com", None), ["cdn.example.com"])
+        self.assertEqual(build_sni_pool("", None), ["www.google.com"])
+
+
+class RangeParsingTests(unittest.TestCase):
+    def test_parse_content_range_accepts_valid_values(self):
+        self.assertEqual(parse_content_range("bytes 10-19/20"), (10, 19, 20))
+
+    def test_parse_content_range_rejects_invalid_values(self):
+        self.assertIsNone(parse_content_range(""))
+        self.assertIsNone(parse_content_range("bytes 10-19/*"))
+        self.assertIsNone(parse_content_range("bytes 10-9/20"))
+        self.assertIsNone(parse_content_range("bytes 10-19/19"))
+
+    def test_validate_range_response_success_and_failures(self):
+        headers = {"content-range": "bytes 10-13/20"}
+        body = b"data"
+
+        self.assertIsNone(validate_range_response(206, headers, body, 10, 13, 20))
+        self.assertEqual(
+            validate_range_response(200, headers, body, 10, 13, 20),
+            "status 200",
+        )
+        self.assertEqual(
+            validate_range_response(206, {"content-range": "bytes 11-13/20"}, body, 10, 13, 20),
+            "Content-Range mismatch 11-13",
+        )
+        self.assertEqual(
+            validate_range_response(206, headers, b"abc", 10, 13, 20),
+            "short chunk 3/4 B",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()