stack/tests/sem/test_runtime.py

"""Tests for sem.runtime — coverage data attachment."""

from __future__ import annotations

import json
import tempfile
from pathlib import Path

from sem.nodes import NodeKind, SemanticNode, Span
from sem.runtime import attach_coverage


def _make_node(nid: str, start: int, end: int) -> SemanticNode:
    return SemanticNode(
        node_id=nid,
        kind=NodeKind.BRANCH_IF,
        span=Span(start_line=start, end_line=end),
        module="pkg.mod",
    )


def _write_coverage(data: dict) -> Path:
    p = Path(tempfile.mktemp(suffix=".json"))
    p.write_text(json.dumps(data))
    return p


class TestAttachCoverage:
    def test_marks_hit_nodes(self):
        nodes = [_make_node("a", 1, 5), _make_node("b", 10, 15)]
        cov = _write_coverage(
            {
                "files": {
                    "src/pkg/mod.py": {
                        "executed_lines": [1, 2, 3, 4, 5],
                        "missing_lines": [10, 11, 12, 13, 14, 15],
                    }
                }
            }
        )
        try:
            attach_coverage(nodes, cov, "src/pkg/mod.py")
            assert nodes[0].runtime.hit is True
            assert nodes[0].runtime.hit_count == 5
            assert nodes[1].runtime.hit is False
        finally:
            cov.unlink()

    def test_missing_file_key_is_noop(self):
        nodes = [_make_node("a", 1, 5)]
        cov = _write_coverage({"files": {}})
        try:
            attach_coverage(nodes, cov, "nonexistent.py")
            assert nodes[0].runtime.hit is False
        finally:
            cov.unlink()

    def test_contexts_attached(self):
        nodes = [_make_node("a", 1, 3)]
        cov = _write_coverage(
            {
                "files": {
                    "mod.py": {
                        "executed_lines": [1, 2, 3],
                        "missing_lines": [],
                        "contexts": {
                            "2": ["test_foo", "test_bar"],
                        },
                    }
                }
            }
        )
        try:
            attach_coverage(nodes, cov, "mod.py")
            assert "test_foo" in nodes[0].runtime.tests_seen
            assert "test_bar" in nodes[0].runtime.tests_seen
        finally:
            cov.unlink()