fix ipv6 display in startup info log (sanic-org#2285)

* fix ipv6 display in startup info log

* refactored to oneliner by request

* Added test for passing ipv4 host

* Added test for passing ipv6 any host

* Added test for passing ipv6 loopback host

sanic/app.py

@@ -1337,7 +1337,9 @@ def _helper(
             if unix:
                 logger.info(f"Goin' Fast @ {unix} {proto}://...")
             else:
-                logger.info(f"Goin' Fast @ {proto}://{host}:{port}")
+                # colon(:) is legal for a host only in an ipv6 address
+                display_host = f"[{host}]" if ":" in host else host
+                logger.info(f"Goin' Fast @ {proto}://{display_host}:{port}")
 
         debug_mode = "enabled" if self.debug else "disabled"
         reload_mode = "enabled" if auto_reload else "disabled"

tests/test_cli.py

@@ -62,6 +62,57 @@ def test_host_port(cmd):
     assert firstline == b"Goin' Fast @ http://localhost:9999"
 
 
+@pytest.mark.parametrize(
+    "cmd",
+    (
+        ("--host=127.0.0.127", "--port=9999"),
+        ("-H", "127.0.0.127", "-p", "9999"),
+    ),
+)
+def test_host_port(cmd):
+    command = ["sanic", "fake.server.app", *cmd]
+    out, err, exitcode = capture(command)
+    lines = out.split(b"\n")
+    firstline = lines[6]
+
+    assert exitcode != 1
+    assert firstline == b"Goin' Fast @ http://127.0.0.127:9999"
+
+
+@pytest.mark.parametrize(
+    "cmd",
+    (
+        ("--host=::", "--port=9999"),
+        ("-H", "::", "-p", "9999"),
+    ),
+)
+def test_host_port(cmd):
+    command = ["sanic", "fake.server.app", *cmd]
+    out, err, exitcode = capture(command)
+    lines = out.split(b"\n")
+    firstline = lines[6]
+
+    assert exitcode != 1
+    assert firstline == b"Goin' Fast @ http://[::]:9999"
+
+
+@pytest.mark.parametrize(
+    "cmd",
+    (
+        ("--host=::1", "--port=9999"),
+        ("-H", "::1", "-p", "9999"),
+    ),
+)
+def test_host_port(cmd):
+    command = ["sanic", "fake.server.app", *cmd]
+    out, err, exitcode = capture(command)
+    lines = out.split(b"\n")
+    firstline = lines[6]
+
+    assert exitcode != 1
+    assert firstline == b"Goin' Fast @ http://[::1]:9999"
+
+
 @pytest.mark.parametrize(
     "num,cmd",
     (