Add prefix matching tests

tests/test_prefix_matching.py

@@ -0,0 +1,221 @@
+"""Tests for prefix matching in command dispatch."""
+
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from mudlib import commands
+from mudlib.commands import CommandDefinition
+
+
+@pytest.fixture
+def mock_writer():
+    writer = MagicMock()
+    writer.write = MagicMock()
+    writer.drain = AsyncMock()
+    return writer
+
+
+@pytest.fixture
+def mock_reader():
+    return MagicMock()
+
+
+@pytest.fixture
+def player(mock_reader, mock_writer):
+    from mudlib.player import Player
+
+    return Player(
+        name="TestPlayer",
+        x=5,
+        y=5,
+        reader=mock_reader,
+        writer=mock_writer,
+    )
+
+
+async def dummy_handler(player, args):
+    """A simple handler for testing."""
+    player.writer.write(f"Handler called with args: {args}\r\n")
+    await player.writer.drain()
+
+
+@pytest.fixture(autouse=True)
+def clean_registry():
+    """Clear registry before each test."""
+    commands._registry.clear()
+    yield
+    commands._registry.clear()
+
+
+@pytest.mark.asyncio
+async def test_exact_match_still_works(player):
+    """Test that exact matches work as before."""
+    commands.register(
+        CommandDefinition(name="look", handler=dummy_handler, mode="normal")
+    )
+
+    await commands.dispatch(player, "look")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    assert "Handler called" in output
+    assert "Unknown command" not in output
+
+
+@pytest.mark.asyncio
+async def test_prefix_match_resolves_unique_prefix(player):
+    """Test that a unique prefix resolves to the full command."""
+    commands.register(
+        CommandDefinition(name="sweep", handler=dummy_handler, mode="normal")
+    )
+
+    await commands.dispatch(player, "swe")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    assert "Handler called" in output
+    assert "Unknown command" not in output
+
+
+@pytest.mark.asyncio
+async def test_ambiguous_prefix_two_matches(player):
+    """Test that ambiguous prefix with 2 matches shows 'A or B?' message."""
+    commands.register(
+        CommandDefinition(name="sweep", handler=dummy_handler, mode="normal")
+    )
+    commands.register(
+        CommandDefinition(
+            name="southwest", handler=dummy_handler, mode="normal"
+        )
+    )
+
+    await commands.dispatch(player, "sw")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    # Check for either order
+    assert (
+        "sweep or southwest?" in output or "southwest or sweep?" in output
+    )
+    assert "Handler called" not in output
+
+
+@pytest.mark.asyncio
+async def test_ambiguous_prefix_three_plus_matches(player):
+    """Test that ambiguous prefix with 3+ matches shows comma-separated."""
+    commands.register(
+        CommandDefinition(name="send", handler=dummy_handler, mode="normal")
+    )
+    commands.register(
+        CommandDefinition(name="set", handler=dummy_handler, mode="normal")
+    )
+    commands.register(
+        CommandDefinition(
+            name="settings", handler=dummy_handler, mode="normal"
+        )
+    )
+
+    await commands.dispatch(player, "se")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    # Should contain all three with commas and "or"
+    assert "send" in output
+    assert "set" in output
+    assert "settings" in output
+    assert ", or " in output
+    assert "Handler called" not in output
+
+
+@pytest.mark.asyncio
+async def test_no_match_shows_unknown_command(player):
+    """Test that no match shows unknown command message."""
+    commands.register(
+        CommandDefinition(name="look", handler=dummy_handler, mode="normal")
+    )
+
+    await commands.dispatch(player, "xyz")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    assert "Unknown command: xyz" in output
+    assert "Handler called" not in output
+
+
+@pytest.mark.asyncio
+async def test_exact_alias_match_wins_over_prefix(player):
+    """Test that exact match on alias takes priority over prefix match."""
+    commands.register(
+        CommandDefinition(
+            name="southwest",
+            aliases=["sw"],
+            handler=dummy_handler,
+            mode="normal",
+        )
+    )
+    commands.register(
+        CommandDefinition(name="sweep", handler=dummy_handler, mode="normal")
+    )
+
+    await commands.dispatch(player, "sw")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    # Should call handler (exact match on alias), not show ambiguous
+    assert "Handler called" in output
+    assert "or" not in output
+
+
+@pytest.mark.asyncio
+async def test_single_char_ambiguous_prefix(player):
+    """Test that single-char ambiguous prefix shows disambiguation."""
+    commands.register(
+        CommandDefinition(name="quit", handler=dummy_handler, mode="normal")
+    )
+    commands.register(
+        CommandDefinition(name="query", handler=dummy_handler, mode="normal")
+    )
+
+    await commands.dispatch(player, "q")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    assert "quit or query?" in output or "query or quit?" in output
+    assert "Handler called" not in output
+
+
+@pytest.mark.asyncio
+async def test_prefix_match_deduplicates_aliases(player):
+    """Test that aliases to the same command don't create multiple matches."""
+    commands.register(
+        CommandDefinition(
+            name="look",
+            aliases=["l", "lo"],
+            handler=dummy_handler,
+            mode="normal",
+        )
+    )
+    commands.register(
+        CommandDefinition(name="lock", handler=dummy_handler, mode="normal")
+    )
+
+    await commands.dispatch(player, "lo")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    # Should show just "lock or look?" not multiple entries for look's aliases
+    assert "lock" in output
+    assert "look" in output
+    # Should not list look multiple times
+    output_lower = output.lower()
+    # Count occurrences of the word "look" (not as substring)
+    look_count = len(
+        [word for word in output_lower.split() if word.startswith("look")]
+    )
+    assert look_count == 1
+
+
+@pytest.mark.asyncio
+async def test_prefix_match_with_args(player):
+    """Test that prefix matching preserves arguments."""
+    commands.register(
+        CommandDefinition(name="sweep", handler=dummy_handler, mode="normal")
+    )
+
+    await commands.dispatch(player, "swe the floor")
+    output = "".join([call[0][0] for call in player.writer.write.call_args_list])
+
+    assert "Handler called with args: the floor" in output