feat: add addr_to_addr_info util for converting addr to addr_infos (#27)

README.md

@@ -74,6 +74,8 @@ pop_addr_infos_interleave(addr_info, 1)
 # Remove all matching address from addr_info
 remove_addr_infos(addr_info, "dead::beef::")
 
+# Convert a local_addr to local_addr_infos
+local_addr_infos = addr_to_addr_infos(("127.0.0.1",0))
 ```
 
 ## Credits

docs/usage.md

@@ -22,4 +22,7 @@ aiohappyeyeballs.pop_addr_infos_interleave(addr_info, 1)
 
 # Remove all matching address from addr_info
 aiohappyeyeballs.remove_addr_infos(addr_info, "dead::beef::")
+
+# Convert a local_addr to local_addr_infos
+local_addr_infos = addr_to_addr_infos(("127.0.0.1",0))
 ```

src/aiohappyeyeballs/__init__.py

@@ -2,11 +2,12 @@
 
 from .impl import start_connection
 from .types import AddrInfoType
-from .utils import pop_addr_infos_interleave, remove_addr_infos
+from .utils import addr_to_addr_infos, pop_addr_infos_interleave, remove_addr_infos
 
 __all__ = (
     "start_connection",
     "AddrInfoType",
     "remove_addr_infos",
     "pop_addr_infos_interleave",
+    "addr_to_addr_infos",
 )

src/aiohappyeyeballs/utils.py

@@ -1,11 +1,39 @@
 """Utility functions for aiohappyeyeballs."""
 
 import ipaddress
-from typing import Dict, List, Tuple, Union
+import socket
+from typing import Dict, List, Optional, Tuple, Union
 
 from .types import AddrInfoType
 
 
+def addr_to_addr_infos(
+    addr: Optional[
+        Union[Tuple[str, int, int, int], Tuple[str, int, int], Tuple[str, int]]
+    ]
+) -> Optional[List[AddrInfoType]]:
+    """Convert an address tuple to a list of addr_info tuples."""
+    if addr is None:
+        return None
+    host = addr[0]
+    port = addr[1]
+    is_ipv6 = ":" in host
+    if is_ipv6:
+        flowinfo = 0
+        scopeid = 0
+        addr_len = len(addr)
+        if addr_len >= 4:
+            scopeid = addr[3]  # type: ignore[misc]
+        if addr_len >= 3:
+            flowinfo = addr[2]  # type: ignore[misc]
+        addr = (host, port, flowinfo, scopeid)
+        family = socket.AF_INET6
+    else:
+        addr = (host, port)
+        family = socket.AF_INET
+    return [(family, socket.SOCK_STREAM, socket.IPPROTO_TCP, "", addr)]
+
+
 def pop_addr_infos_interleave(addr_infos: List[AddrInfoType], interleave: int) -> None:
     """
     Pop addr_info from the list of addr_infos by family up to interleave times.

tests/test_utils.py

@@ -3,7 +3,12 @@
 
 import pytest
 
-from aiohappyeyeballs import AddrInfoType, pop_addr_infos_interleave, remove_addr_infos
+from aiohappyeyeballs import (
+    AddrInfoType,
+    addr_to_addr_infos,
+    pop_addr_infos_interleave,
+    remove_addr_infos,
+)
 
 
 def test_pop_addr_infos_interleave():
@@ -114,3 +119,64 @@ def test_remove_addr_infos_slow_path():
     ):
         remove_addr_infos(addr_info_copy, ("107.6.106.2", 80))
     assert addr_info_copy == [ipv4_addr_info]
+
+
+def test_addr_to_addr_infos():
+    """Test addr_to_addr_infos."""
+    assert addr_to_addr_infos(("1.2.3.4", 43)) == [
+        (
+            socket.AF_INET,
+            socket.SOCK_STREAM,
+            socket.IPPROTO_TCP,
+            "",
+            ("1.2.3.4", 43),
+        )
+    ]
+    assert addr_to_addr_infos(
+        ("dead:aaaa:0000:0000:0000:0000:0000:0000", 80, 0, 0)
+    ) == [
+        (
+            socket.AF_INET6,
+            socket.SOCK_STREAM,
+            socket.IPPROTO_TCP,
+            "",
+            ("dead:aaaa:0000:0000:0000:0000:0000:0000", 80, 0, 0),
+        )
+    ]
+    assert addr_to_addr_infos(("dead:aaaa::", 80, 0, 0)) == [
+        (
+            socket.AF_INET6,
+            socket.SOCK_STREAM,
+            socket.IPPROTO_TCP,
+            "",
+            ("dead:aaaa::", 80, 0, 0),
+        )
+    ]
+    assert addr_to_addr_infos(("dead:aaaa::", 80)) == [
+        (
+            socket.AF_INET6,
+            socket.SOCK_STREAM,
+            socket.IPPROTO_TCP,
+            "",
+            ("dead:aaaa::", 80, 0, 0),
+        )
+    ]
+    assert addr_to_addr_infos(("dead:aaaa::", 80, 1)) == [
+        (
+            socket.AF_INET6,
+            socket.SOCK_STREAM,
+            socket.IPPROTO_TCP,
+            "",
+            ("dead:aaaa::", 80, 1, 0),
+        )
+    ]
+    assert addr_to_addr_infos(("dead:aaaa::", 80, 1, 1)) == [
+        (
+            socket.AF_INET6,
+            socket.SOCK_STREAM,
+            socket.IPPROTO_TCP,
+            "",
+            ("dead:aaaa::", 80, 1, 1),
+        )
+    ]
+    assert addr_to_addr_infos(None) is None