from __future__ import annotations

import networkx as nx

from graphify.multigraph_compat import (

CapabilityCheck,

MultigraphCapabilityResult,

probe_multigraph_capabilities,

require_multigraph_capabilities,

)

def test_probe_multigraph_capabilities_passes_current_runtime() -> None:

result = probe_multigraph_capabilities()

assert result.ok, result.error_message()

assert result.python_version

assert result.networkx_version

assert {check.name for check in result.checks} == {

"keyed_parallel_edges",

"node_link_edges_links_round_trip",

"duplicate_key_overwrite_semantics",

"reserved_key_attr_rejected",

"remove_edges_from_two_tuple_semantics",

"to_undirected_preserves_multigraph_type",

}

def test_require_multigraph_capabilities_returns_result() -> None:

result = require_multigraph_capabilities()

assert result.ok

def test_failure_message_is_actionable() -> None:

result = MultigraphCapabilityResult(

python_version="3.10.0",

networkx_version="0.0",

checks=(CapabilityCheck("node_link_edges_links_round_trip", False, "boom"),),

)

message = result.error_message()

assert "--multigraph requires NetworkX keyed MultiDiGraph node-link" in message

assert "Default simple graph mode remains available" in message

assert "node_link_edges_links_round_trip: boom" in message

def test_networkx_duplicate_key_overwrite_trap_is_real() -> None:

graph = nx.MultiDiGraph()

graph.add_edge("a", "b", key="same", relation="first")

graph.add_edge("a", "b", key="same", relation="second")

assert graph.number_of_edges("a", "b") == 1

assert graph["a"]["b"]["same"]["relation"] == "second"