Tests: Add automated testing framework with coverage support

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/test_ir_generation.py

@@ -0,0 +1,29 @@
+"""
+Level 1 — IR Generation tests.
+
+For every BPF test file, calls compile_to_ir() and asserts:
+  1. No exception is raised by the pythonbpf compiler.
+  2. No logging.ERROR records are emitted during compilation.
+  3. A .ll file is produced.
+
+Tests in failing_tests/ are marked xfail (strict=True) by conftest.py —
+they must raise an exception or produce an ERROR log to pass the suite.
+"""
+
+import logging
+from pathlib import Path
+
+
+from tests.framework.compiler import run_ir_generation
+
+
+def test_ir_generation(bpf_test_file: Path, tmp_path, caplog):
+    ll_path = tmp_path / "output.ll"
+
+    run_ir_generation(bpf_test_file, ll_path)
+
+    error_records = [r for r in caplog.records if r.levelno >= logging.ERROR]
+    assert not error_records, "IR generation produced ERROR log(s):\n" + "\n".join(
+        f"  [{r.name}] {r.getMessage()}" for r in error_records
+    )
+    assert ll_path.exists(), "compile_to_ir() returned without writing a .ll file"