Improve representation of frames.

Specifically this avoids cutting log messages in two lines.

Ref #765.

Author: aaugustin

src/websockets/frames.py

@@ -129,7 +129,7 @@ def __str__(self) -> str:
         if self.opcode is OP_TEXT:
             # Decoding only the beginning and the end is needlessly hard.
             # Decode the entire payload then elide later if necessary.
-            data = self.data.decode()
+            data = repr(self.data.decode())
         elif self.opcode is OP_BINARY:
             # We'll show at most the first 16 bytes and the last 8 bytes.
             # Encode just what we need, plus two dummy bytes to elide later.
@@ -145,7 +145,7 @@ def __str__(self) -> str:
             # Ping and Pong frames could contain UTF-8. Attempt to decode as
             # UTF-8 and display it as text; fallback to binary.
             try:
-                data = self.data.decode()
+                data = repr(self.data.decode())
                 coding = "text"
             except UnicodeDecodeError:
                 binary = self.data
@@ -154,7 +154,7 @@ def __str__(self) -> str:
                 data = " ".join(f"{byte:02x}" for byte in binary)
                 coding = "binary"
         else:
-            data = ""
+            data = "''"
 
         if len(data) > 75:
             data = data[:48] + "..." + data[-24:]

tests/test_frames.py

@@ -198,7 +198,7 @@ class StrTests(unittest.TestCase):
     def test_cont_text(self):
         self.assertEqual(
             str(Frame(OP_CONT, b" cr\xc3\xa8me", fin=False)),
-            "CONT  crème [text, 7 bytes, continued]",
+            "CONT ' crème' [text, 7 bytes, continued]",
         )
 
     def test_cont_binary(self):
@@ -210,7 +210,7 @@ def test_cont_binary(self):
     def test_cont_final_text(self):
         self.assertEqual(
             str(Frame(OP_CONT, b" cr\xc3\xa8me")),
-            "CONT  crème [text, 7 bytes]",
+            "CONT ' crème' [text, 7 bytes]",
         )
 
     def test_cont_final_binary(self):
@@ -222,8 +222,8 @@ def test_cont_final_binary(self):
     def test_cont_text_truncated(self):
         self.assertEqual(
             str(Frame(OP_CONT, b"caf\xc3\xa9 " * 16, fin=False)),
-            "CONT café café café café café café café café café caf..."
-            "afé café café café café  [text, 96 bytes, continued]",
+            "CONT 'café café café café café café café café café ca..."
+            "fé café café café café ' [text, 96 bytes, continued]",
         )
 
     def test_cont_binary_truncated(self):
@@ -236,20 +236,26 @@ def test_cont_binary_truncated(self):
     def test_text(self):
         self.assertEqual(
             str(Frame(OP_TEXT, b"caf\xc3\xa9")),
-            "TEXT café [5 bytes]",
+            "TEXT 'café' [5 bytes]",
         )
 
     def test_text_non_final(self):
         self.assertEqual(
             str(Frame(OP_TEXT, b"caf\xc3\xa9", fin=False)),
-            "TEXT café [5 bytes, continued]",
+            "TEXT 'café' [5 bytes, continued]",
         )
 
     def test_text_truncated(self):
         self.assertEqual(
             str(Frame(OP_TEXT, b"caf\xc3\xa9 " * 16)),
-            "TEXT café café café café café café café café café caf..."
-            "afé café café café café  [96 bytes]",
+            "TEXT 'café café café café café café café café café ca..."
+            "fé café café café café ' [96 bytes]",
+        )
+
+    def test_text_with_newline(self):
+        self.assertEqual(
+            str(Frame(OP_TEXT, b"Hello\nworld!")),
+            "TEXT 'Hello\\nworld!' [12 bytes]",
         )
 
     def test_binary(self):
@@ -286,13 +292,19 @@ def test_close_reason(self):
     def test_ping(self):
         self.assertEqual(
             str(Frame(OP_PING, b"")),
-            "PING  [0 bytes]",
+            "PING '' [0 bytes]",
         )
 
     def test_ping_text(self):
         self.assertEqual(
             str(Frame(OP_PING, b"ping")),
-            "PING ping [text, 4 bytes]",
+            "PING 'ping' [text, 4 bytes]",
+        )
+
+    def test_ping_text_with_newline(self):
+        self.assertEqual(
+            str(Frame(OP_PING, b"ping\n")),
+            "PING 'ping\\n' [text, 5 bytes]",
         )
 
     def test_ping_binary(self):
@@ -304,13 +316,19 @@ def test_ping_binary(self):
     def test_pong(self):
         self.assertEqual(
             str(Frame(OP_PONG, b"")),
-            "PONG  [0 bytes]",
+            "PONG '' [0 bytes]",
         )
 
     def test_pong_text(self):
         self.assertEqual(
             str(Frame(OP_PONG, b"pong")),
-            "PONG pong [text, 4 bytes]",
+            "PONG 'pong' [text, 4 bytes]",
+        )
+
+    def test_pong_text_with_newline(self):
+        self.assertEqual(
+            str(Frame(OP_PONG, b"pong\n")),
+            "PONG 'pong\\n' [text, 5 bytes]",
         )
 
     def test_pong_binary(self):