feat: add vulnerability scanner for issue #108

- scripts/vulnerability_scanner.py: scan Python dependencies against OSV CVE database - tests/test_vulnerability_scanner.py: 10 comprehensive tests - Supports requirements.txt parsing with -r includes - Outputs text, JSON, and markdown reports - Filters by severity (critical/high/medium/low) - Exit codes 0/1/2 for CI integration
2026-04-26 20:40:12 -04:00
parent 4b5a675355
commit a46d465d2d
2 changed files with 702 additions and 0 deletions
--- a/scripts/vulnerability_scanner.py
+++ b/scripts/vulnerability_scanner.py
@@ -0,0 +1,465 @@
+#!/usr/bin/env python3
+"""
+vulnerability_scanner.py — Check Python dependencies against CVE databases (Issue #108)
+
+Scans requirements.txt (or any pip-compatible dependency file) and queries
+the Open Source Vulnerability (OSV) database for known security issues.
+
+OSV API: https://api.osv.dev/v1/query  (free, no auth, PyPI ecosystem supported)
+
+Output:
+  - Human-readable summary on stdout
+  - JSON report with full vulnerability details
+  - Exit code: 0 if no vulnerabilities found, 1 if critical/high found, 2 otherwise
+
+Usage:
+  python3 scripts/vulnerability_scanner.py
+  python3 scripts/vulnerability_scanner.py --deps requirements.txt --output json
+  python3 scripts/vulnerability_scanner.py --min-severity high
+  python3 scripts/vulnerability_scanner.py --deps requirements.txt --report-format markdown
+"""
+
+import argparse
+import json
+import os
+import re
+import sys
+import urllib.request
+import urllib.error
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Dict, List, Optional, Tuple
+
+# --- Configuration ---
+
+OSV_API_URL = "https://api.osv.dev/v1/query"
+DEFAULT_REQUIREMENTS_PATH = "requirements.txt"
+SEVERITY_LEVELS = ["critical", "high", "medium", "low", "unknown"]
+
+# Map OSV severities to our buckets
+CVSS_SEVERITY_MAP = {
+    "CRITICAL": "critical",
+    "HIGH": "high",
+    "MEDIUM": "medium",
+    "LOW": "low",
+    "NONE": "none",
+}
+
+# --- Data Structures ---
+
+
+@dataclass
+class Vulnerability:
+    """A single vulnerability finding."""
+    package: str
+    version: str
+    vuln_id: str
+    severity: str
+    cvss_score: Optional[float]
+    summary: str
+    details_url: str
+    fixed_versions: List[str]
+
+
+@dataclass
+class ScanResult:
+    """Results from a vulnerability scan."""
+    scanned_packages: int
+    vulnerabilities: List[Vulnerability]
+    errors: List[Tuple[str, str]]  # (package, error_message)
+
+
+# --- Requirement Parsing ---
+
+
+def parse_requirements_file(path: str) -> Dict[str, str]:
+    """
+    Parse a requirements.txt file into {package_name: version_spec}.
+
+    Handles:
+      - pkg==1.2.3
+      - pkg>=1.0.0
+      - pkg[extra]==1.2.3
+      - -e/--editable entries (skipped)
+      - -r inclusions (recursive, limited depth)
+      - comments and blank lines
+    """
+    packages = {}
+    processed_includes = set()
+
+    def parse_line(line: str, filename: str, depth: int = 0) -> None:
+        if depth > 3:
+            print(f"WARNING: Max include depth exceeded in {filename}", file=sys.stderr)
+            return
+
+        line = line.strip()
+        if not line or line.startswith('#'):
+            return
+
+        # Handle -r or --requirement includes
+        if line.startswith('-r ') or line.startswith('--requirement '):
+            if depth >= 3:
+                return
+            include_path = line.split(None, 1)[1].strip()
+            # Resolve relative to current file's directory
+            base_dir = os.path.dirname(os.path.abspath(filename))
+            full_path = os.path.join(base_dir, include_path)
+            if full_path not in processed_includes:
+                processed_includes.add(full_path)
+                try:
+                    with open(full_path, 'r', encoding='utf-8') as f:
+                        for incl_line in f:
+                            parse_line(incl_line, full_path, depth + 1)
+                except FileNotFoundError:
+                    print(f"WARNING: Could not read included file: {full_path}", file=sys.stderr)
+            return
+
+        # Skip editable installs and other flags
+        if line.startswith('-e ') or line.startswith('--editable ') or line.startswith('-'):
+            return
+
+        # Extract package name and version spec
+        # Handles: pkg==1.2.3, pkg>=1.0, pkg[extra]==1.2.3, pkg ~= 1.0
+        match = re.match(
+            r'^([a-zA-Z0-9]([a-zA-Z0-9._-]*[a-zA-Z0-9])?)(\s*[[,{])?.*?((==|>=|<=|~=|!=|===)\s*([^\s;#]+))?',
+            line
+        )
+        if not match:
+            # Try simpler: name at start before any comparison
+            simple = re.match(r'^([a-zA-Z0-9][-a-zA-Z0-9_.]*)', line)
+            if simple:
+                pkg = simple.group(1).lower()
+                packages[pkg] = ""
+            return
+
+        pkg_name = match.group(1).lower()
+        # Strip extras like django[argon2] -> django
+        pkg_name = re.sub(r'\[.*?\]', '', pkg_name).strip()
+
+        version = ""
+        if match.group(5):  # comparison operator + version
+            version = match.group(5) + match.group(6)
+
+        packages[pkg_name] = version
+
+    # Read and parse the file
+    try:
+        with open(path, 'r', encoding='utf-8') as f:
+            for line in f:
+                parse_line(line, path, 0)
+    except FileNotFoundError:
+        print(f"ERROR: Requirements file not found: {path}", file=sys.stderr)
+        sys.exit(1)
+
+    return packages
+
+
+# --- OSV API Queries ---
+
+
+def query_osv(package: str, version: str) -> List[dict]:
+    """
+    Query the OSV API for vulnerabilities affecting a specific package version.
+
+    Returns list of vulnerability dicts (raw API response) or empty list on error.
+    """
+    # Normalize version spec for OSV query
+    # OSV expects a specific version, not a range. We query for the exact version
+    # if available, otherwise we query without version to get all vulns for the package
+    # and let the caller filter.
+    query_version = version if re.match(r'^[0-9]', version) else None
+
+    payload = {
+        "package": {
+            "name": package,
+            "ecosystem": "PyPI"
+        }
+    }
+    if query_version:
+        payload["version"] = query_version
+
+    data = json.dumps(payload).encode('utf-8')
+    req = urllib.request.Request(
+        OSV_API_URL,
+        data=data,
+        headers={'Content-Type': 'application/json'},
+        method='POST'
+    )
+
+    try:
+        with urllib.request.urlopen(req, timeout=15) as response:
+            result = json.loads(response.read().decode('utf-8'))
+            return result.get('vulns', []) + result.get('vulnerabilities', [])
+    except urllib.error.HTTPError as e:
+        if e.code == 404:
+            return []  # No vulnerabilities found
+        print(f"WARNING: OSV query failed for {package}: HTTP {e.code}", file=sys.stderr)
+    except (urllib.error.URLError, json.JSONDecodeError, TimeoutError) as e:
+        print(f"WARNING: OSV query failed for {package}: {e}", file=sys.stderr)
+
+    return []
+
+
+def parse_osv_vuln(raw_vulns: List[dict], package: str, version_spec: str) -> List[Vulnerability]:
+    """
+    Parse raw OSV API responses into Vulnerability objects.
+    """
+    vulns = []
+    for v in raw_vulns:
+        vuln_id = v.get('id', 'UNKNOWN')
+        summary = v.get('summary', 'No summary provided.')
+
+        # Severity from CVSS or ecosystem-specific
+        severity = "unknown"
+        cvss_score = None
+        if 'severity' in v:
+            for sev_info in v['severity']:
+                if sev_info.get('type') == 'CVSS_V3':
+                    score = sev_info.get('score', '')
+                    if isinstance(score, dict):
+                        cvss_score = score.get('baseScore')
+                        sev_str = score.get('baseSeverity', '').upper()
+                        severity = CVSS_SEVERITY_MAP.get(sev_str, 'unknown')
+                    break
+                elif sev_info.get('type') == 'CVSS_V2':
+                    # Fallback
+                    score = sev_info.get('score', '')
+                    if isinstance(score, dict):
+                        cvss_score = score.get('baseScore')
+                        sev_str = sev_info.get('type', '').upper()
+                        severity = "unknown"
+
+        # Affected packages/ranges
+        affected = v.get('affected', [])
+        fixed_versions = []
+        for aff in affected:
+            for r in aff.get('ranges', []):
+                for event in r.get('events', []):
+                    if event.get('introduced'):
+                        # We have the version, fixed would be in 'fixed' events
+                        pass
+                    if event.get('fixed'):
+                        fixed_versions.append(event['fixed'])
+
+        # Build details URL
+        details_url = f"https://osv.dev/vulnerability/{vuln_id}"
+
+        vuln = Vulnerability(
+            package=package,
+            version=version_spec,
+            vuln_id=vuln_id,
+            severity=severity,
+            cvss_score=cvss_score,
+            summary=summary,
+            details_url=details_url,
+            fixed_versions=list(set(fixed_versions))
+        )
+        vulns.append(vuln)
+
+    return vulns
+
+
+# --- Filtering & Reporting ---
+
+
+def filter_by_severity(vulns: List[Vulnerability], min_severity: str) -> List[Vulnerability]:
+    """Filter vulnerabilities to include only those at or above the given severity."""
+    if min_severity.lower() not in SEVERITY_LEVELS:
+        return vulns  # No filtering if invalid
+
+    min_idx = SEVERITY_LEVELS.index(min_severity.lower())
+    filtered = []
+    for v in vulns:
+        sev_idx = SEVERITY_LEVELS.index(v.severity.lower())
+        if sev_idx <= min_idx:  # lower index = more severe
+            filtered.append(v)
+    return filtered
+
+
+def generate_text_report(result: ScanResult, packages: Dict[str, str]) -> str:
+    """Generate human-readable text report."""
+    lines = []
+    lines.append("=" * 60)
+    lines.append("Vulnerability Scan Report")
+    lines.append("=" * 60)
+    lines.append(f"Packages scanned: {result.scanned_packages}")
+    lines.append(f"Vulnerabilities found: {len(result.vulnerabilities)}")
+
+    if result.errors:
+        lines.append(f"Errors: {len(result.errors)}")
+
+    # Group by severity
+    by_severity: Dict[str, List[Vulnerability]] = {}
+    for v in result.vulnerabilities:
+        by_severity.setdefault(v.severity.upper(), []).append(v)
+
+    for sev in ["CRITICAL", "HIGH", "MEDIUM", "LOW", "UNKNOWN"]:
+        vuln_list = by_severity.get(sev, [])
+        if vuln_list:
+            lines.append(f"\n{sev}: {len(vuln_list)}")
+            for v in vuln_list:
+                lines.append(f"  [{v.package} {packages.get(v.package, '')}] {v.vuln_id}")
+                lines.append(f"    {v.summary[:80]}")
+                if v.cvss_score:
+                    lines.append(f"    CVSS: {v.cvss_score}")
+                if v.fixed_versions:
+                    lines.append(f"    Fixed in: {', '.join(v.fixed_versions[:3])}")
+                lines.append(f"    {v.details_url}")
+
+    if result.errors:
+        lines.append("\nERRORS:")
+        for pkg, err in result.errors[:10]:
+            lines.append(f"  {pkg}: {err}")
+
+    lines.append("\n" + "=" * 60)
+    return "\n".join(lines)
+
+
+def generate_json_report(result: ScanResult, packages: Dict[str, str]) -> str:
+    """Generate JSON report."""
+    report = {
+        "scanned_packages": result.scanned_packages,
+        "vulnerabilities": [
+            {
+                "package": v.package,
+                "version_spec": packages.get(v.package, v.version),
+                "vulnerability_id": v.vuln_id,
+                "severity": v.severity,
+                "cvss_score": v.cvss_score,
+                "summary": v.summary,
+                "details_url": v.details_url,
+                "fixed_versions": v.fixed_versions,
+            }
+            for v in result.vulnerabilities
+        ],
+        "errors": [{"package": p, "error": e} for p, e in result.errors],
+    }
+    return json.dumps(report, indent=2)
+
+
+# --- Main Orchestration ---
+
+
+def run_scan(
+    deps_path: str,
+    min_severity: str = "low",
+    query_osv_api: bool = True
+) -> ScanResult:
+    """
+    Execute the full vulnerability scan pipeline.
+
+    Args:
+        deps_path: Path to requirements-style file
+        min_severity: Minimum severity to include in results
+        query_osv_api: If False, skip API calls (for testing/dry-run)
+
+    Returns:
+        ScanResult with all findings
+    """
+    # 1. Parse dependencies
+    packages = parse_requirements_file(deps_path)
+    if not packages:
+        return ScanResult(scanned_packages=0, vulnerabilities=[], errors=[])
+
+    # 2. Query OSV for each package
+    vulnerabilities: List[Vulnerability] = []
+    errors: List[Tuple[str, str]] = []
+
+    for pkg, version_spec in packages.items():
+        if not query_osv_api:
+            continue
+
+        raw_vulns = query_osv(pkg, version_spec or "")
+        if raw_vulns:
+            parsed = parse_osv_vuln(raw_vulns, pkg, version_spec or "")
+            vulnerabilities.extend(parsed)
+
+    # 3. Filter by severity
+    filtered = filter_by_severity(vulnerabilities, min_severity)
+
+    # 4. Build result
+    return ScanResult(
+        scanned_packages=len(packages),
+        vulnerabilities=filtered,
+        errors=errors
+    )
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(
+        description="Scan Python dependencies for known vulnerabilities using OSV database"
+    )
+    parser.add_argument(
+        '--deps', '-d',
+        default=DEFAULT_REQUIREMENTS_PATH,
+        help='Path to requirements.txt (default: requirements.txt)'
+    )
+    parser.add_argument(
+        '--output', '-o',
+        choices=['text', 'json', 'markdown'],
+        default='text',
+        help='Output format (default: text)'
+    )
+    parser.add_argument(
+        '--min-severity',
+        default='low',
+        choices=SEVERITY_LEVELS,
+        help='Minimum severity to report (default: low — report all)'
+    )
+    parser.add_argument(
+        '--json',
+        action='store_true',
+        help='Output JSON (shorthand for --output json)'
+    )
+    parser.add_argument(
+        '--quiet', '-q',
+        action='store_true',
+        help='Only print summary, skip detailed vulnerability list'
+    )
+
+    args = parser.parse_args()
+
+    # Update output if --json flag is used
+    if args.json:
+        args.output = 'json'
+
+    # Run the scan
+    result = run_scan(args.deps, args.min_severity, query_osv_api=True)
+
+    # Output
+    if args.output == 'json':
+        print(generate_json_report(result, parse_requirements_file(args.deps)))
+    elif args.output == 'markdown':
+        # Simple markdown table
+        print("# Vulnerability Scan Report\n")
+        print(f"**Packages scanned:** {result.scanned_packages}")
+        print(f"**Vulnerabilities:** {len(result.vulnerabilities)}\n")
+        if result.vulnerabilities:
+            print("| Severity | Package | Version | Vuln ID | Summary |")
+            print("|----------|---------|---------|---------|---------|")
+            for v in result.vulnerabilities:
+                print(f"| {v.severity.upper()} | {v.package} | {v.version} | [{v.vuln_id}]({v.details_url}) | {v.summary[:50]} |")
+        print("\n")
+    else:
+        # text (default)
+        if not args.quiet:
+            print(generate_text_report(result, parse_requirements_file(args.deps)))
+        else:
+            crit = sum(1 for v in result.vulnerabilities if v.severity == 'critical')
+            high = sum(1 for v in result.vulnerabilities if v.severity == 'high')
+            med = sum(1 for v in result.vulnerabilities if v.severity == 'medium')
+            print(f"CRITICAL={crit} HIGH={high} MEDIUM={med} TOTAL={len(result.vulnerabilities)}")
+
+    # Exit code logic: 0 if no vulns at min_severity+, 1 if critical/high found, 2 for other vulns
+    has_critical_high = any(v.severity in ('critical', 'high') for v in result.vulnerabilities)
+    has_other = any(v.severity not in ('critical', 'high') for v in result.vulnerabilities)
+
+    if has_critical_high:
+        return 1
+    elif has_other:
+        return 2
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())
--- a/tests/test_vulnerability_scanner.py
+++ b/tests/test_vulnerability_scanner.py
@@ -0,0 +1,237 @@
+#!/usr/bin/env python3
+"""Tests for scripts/vulnerability_scanner.py — 10 tests."""
+
+import json
+import os
+import sys
+import tempfile
+import unittest
+from unittest.mock import patch, MagicMock
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__) or ".", ".."))
+import importlib.util
+spec = importlib.util.spec_from_file_location(
+    "vulnerability_scanner",
+    os.path.join(os.path.dirname(__file__) or ".", "..", "scripts", "vulnerability_scanner.py"))
+mod = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(mod)
+
+parse_requirements_file = mod.parse_requirements_file
+query_osv = mod.query_osv
+parse_osv_vuln = mod.parse_osv_vuln
+filter_by_severity = mod.filter_by_severity
+Vulnerability = mod.Vulnerability
+
+
+# --- Test Data ---
+
+SAMPLE_OSV_RESPONSE = [
+    {
+        "id": "GHSA-xxxx-xxxx-xxxx",
+        "summary": " Arbitrary code execution in django",
+        "severity": [{"type": "CVSS_V3", "score": {"baseScore": 9.8, "baseSeverity": "CRITICAL"}}],
+        "affected": [{
+            "ranges": [{
+                "events": [
+                    {"introduced": "0"},
+                    {"fixed": "3.2.14"}
+                ]
+            }]
+        }]
+    },
+    {
+        "id": "PYSEC-2024-1234",
+        "summary": " Denial of service in cryptography",
+        "severity": [{"type": "CVSS_V3", "score": {"baseScore": 5.3, "baseSeverity": "MEDIUM"}}],
+        "affected": [{
+            "ranges": [{
+                "events": [
+                    {"introduced": "0"},
+                    {"fixed": "42.0.0"}
+                ]
+            }]
+        }]
+    }
+]
+
+
+# --- Tests ---
+
+
+def test_parse_requirements_simple():
+    """Should parse a simple requirements file."""
+    with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+        f.write("django==4.2.0\n")
+        f.write("requests>=2.28.0\n")
+        f.write("click~=8.0\n")
+        f.flush()
+        pkgs = parse_requirements_file(f.name)
+        os.unlink(f.name)
+
+    assert "django" in pkgs
+    assert pkgs["django"] == "==4.2.0"
+    assert "requests" in pkgs
+    assert pkgs["requests"] == ">=2.28.0"
+    assert "click" in pkgs
+    print("PASS: test_parse_requirements_simple")
+
+
+def test_parse_requirements_extras_and_comments():
+    """Should skip comments, blank lines, and handle package extras."""
+    with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+        f.write("# This is a comment\n")
+        f.write("django[argon2]==4.2.0\n")
+        f.write("\n")
+        f.write("   requests   >=2.28.0   # inline comment\n")
+        f.flush()
+        pkgs = parse_requirements_file(f.name)
+        os.unlink(f.name)
+
+    assert "django" in pkgs
+    assert pkgs["django"] == "==4.2.0"
+    assert "requests" in pkgs
+    # Version should capture the comparison
+    assert ">=" in pkgs["requests"]
+    print("PASS: test_parse_requirements_extras_and_comments")
+
+
+def test_parse_requirements_include_recursive():
+    """Should follow -r includes up to depth 3."""
+    with tempfile.TemporaryDirectory() as tmpdir:
+        # Main requirements.txt
+        main = os.path.join(tmpdir, "requirements.txt")
+        with open(main, 'w') as f:
+            f.write("django==4.2.0\n")
+            f.write("-r base.txt\n")
+
+        # base.txt
+        base = os.path.join(tmpdir, "base.txt")
+        with open(base, 'w') as f:
+            f.write("requests>=2.28.0\n")
+            f.write("-r deep.txt\n")
+
+        # deep.txt
+        deep = os.path.join(tmpdir, "deep.txt")
+        with open(deep, 'w') as f:
+            f.write("click~=8.0\n")
+
+        pkgs = parse_requirements_file(main)
+
+        assert "django" in pkgs
+        assert "requests" in pkgs
+        assert "click" in pkgs
+        print("PASS: test_parse_requirements_include_recursive")
+
+
+def test_parse_requirements_skip_editable():
+    """Should skip -e editable installs and other flags."""
+    with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+        f.write("-e git+https://github.com/user/repo.git@branch#egg=package\n")
+        f.write("--index-url https://pypi.org/simple\n")
+        f.write("django==4.2.0\n")
+        f.flush()
+        pkgs = parse_requirements_file(f.name)
+        os.unlink(f.name)
+
+    assert "django" in pkgs
+    assert "package" not in pkgs  # should not pick up editable name
+    print("PASS: test_parse_requirements_skip_editable")
+
+
+def test_parse_requirements_nonexistent():
+    """Should exit with error on missing file."""
+    with patch('sys.exit') as mock_exit:
+        pkgs = parse_requirements_file("/nonexistent/requirements.txt")
+        mock_exit.assert_called_once_with(1)
+    print("PASS: test_parse_requirements_nonexistent")
+
+
+def test_filter_by_severity():
+    """Should filter vulnerabilities by severity threshold."""
+    vulns = [
+        Vulnerability("pkg1", "==1.0", "V1", "critical", 9.8, "summary", "url", []),
+        Vulnerability("pkg2", "==2.0", "V2", "high", 7.5, "summary", "url", []),
+        Vulnerability("pkg3", "==3.0", "V3", "medium", 5.0, "summary", "url", []),
+        Vulnerability("pkg4", "==4.0", "V4", "low", 2.0, "summary", "url", []),
+    ]
+
+    # min_severity: low includes all
+    filtered = filter_by_severity(vulns, "low")
+    assert len(filtered) == 4
+
+    # min_severity: medium excludes low
+    filtered = filter_by_severity(vulns, "medium")
+    assert len(filtered) == 3
+    assert all(v.severity in ("critical", "high", "medium") for v in filtered)
+
+    # min_severity: high excludes medium + low
+    filtered = filter_by_severity(vulns, "high")
+    assert len(filtered) == 2
+
+    # min_severity: critical only
+    filtered = filter_by_severity(vulns, "critical")
+    assert len(filtered) == 1
+
+    print("PASS: test_filter_by_severity")
+
+
+def test_parse_osv_vuln():
+    """Should parse OSV API response correctly."""
+    parsed = parse_osv_vuln(SAMPLE_OSV_RESPONSE, "django", "==4.2.0")
+
+    assert len(parsed) == 2
+    assert parsed[0].package == "django"
+    assert parsed[0].vuln_id == "GHSA-xxxx-xxxx-xxxx"
+    assert parsed[0].severity == "critical"
+    assert parsed[0].cvss_score == 9.8
+    assert parsed[1].severity == "medium"
+    assert parsed[1].cvss_score == 5.3
+    print("PASS: test_parse_osv_vuln")
+
+
+def test_parse_osv_vuln_empty():
+    """Should handle empty OSV response."""
+    parsed = parse_osv_vuln([], "django", "==4.2.0")
+    assert parsed == []
+    print("PASS: test_parse_osv_vuln_empty")
+
+
+def test_query_osv_network_success():
+    """Should successfully query OSV API for a real known vulnerable package."""
+    # Query for an old django version that likely has known CVEs
+    # This test actually hits the network — tagged as integration
+    vulns = query_osv("django", "==3.2.0")
+    # We don't assert specific results since vulns change over time
+    # But we assert the function returns a list and doesn't error
+    assert isinstance(vulns, list)
+    print("PASS: test_query_osv_network_success")
+
+
+def test_query_osv_404_no_vulns():
+    """OSV returns empty list for packages with no vulns (404-like)."""
+    # Mock a 404 response from OSV API
+    with patch('urllib.request.urlopen') as mock_urlopen:
+        mock_response = MagicMock()
+        mock_response.read.return_value = b'{"vulns": []}'
+        mock_response.__enter__ = lambda self: self
+        mock_response.__exit__ = lambda self, *args: None
+        mock_urlopen.return_value = mock_response
+
+        result = query_osv("nonexistent-package-xyz123", "==1.0.0")
+        assert result == []
+    print("PASS: test_query_osv_404_no_vulns")
+
+
+if __name__ == '__main__':
+    # Run all tests
+    test_parse_requirements_simple()
+    test_parse_requirements_extras_and_comments()
+    test_parse_requirements_include_recursive()
+    test_parse_requirements_skip_editable()
+    test_parse_requirements_nonexistent()
+    test_filter_by_severity()
+    test_parse_osv_vuln()
+    test_parse_osv_vuln_empty()
+    test_query_osv_network_success()
+    test_query_osv_404_no_vulns()
+    print("\nAll tests passed.")