test: Add dependency resolver tests (#754)

tests/test_skill_deps.py

@@ -0,0 +1,81 @@
+"""
+Tests for skill dependency resolver
+
+Issue: #754
+"""
+
+import unittest
+from unittest.mock import patch, MagicMock
+
+from tools.skill_deps import (
+    parse_requires,
+    check_dependency,
+    check_dependencies,
+    resolve_dependencies,
+)
+
+
+class TestParseRequires(unittest.TestCase):
+    
+    def test_list(self):
+        fm = {"requires": ["pkg1", "pkg2"]}
+        self.assertEqual(parse_requires(fm), ["pkg1", "pkg2"])
+    
+    def test_string(self):
+        fm = {"requires": "pkg1"}
+        self.assertEqual(parse_requires(fm), ["pkg1"])
+    
+    def test_empty(self):
+        fm = {}
+        self.assertEqual(parse_requires(fm), [])
+    
+    def test_none(self):
+        fm = {"requires": None}
+        self.assertEqual(parse_requires(fm), [])
+
+
+class TestCheckDependency(unittest.TestCase):
+    
+    def test_installed(self):
+        installed, version = check_dependency("json")
+        self.assertTrue(installed)
+    
+    def test_not_installed(self):
+        installed, version = check_dependency("nonexistent_package_xyz_123")
+        self.assertFalse(installed)
+
+
+class TestCheckDependencies(unittest.TestCase):
+    
+    def test_all_installed(self):
+        installed, missing = check_dependencies(["json", "os"])
+        self.assertEqual(len(missing), 0)
+    
+    def test_some_missing(self):
+        installed, missing = check_dependencies(["json", "nonexistent_xyz"])
+        self.assertIn("json", installed)
+        self.assertIn("nonexistent_xyz", missing)
+
+
+class TestResolveDependencies(unittest.TestCase):
+    
+    def test_no_requires(self):
+        satisfied, installed, missing = resolve_dependencies({})
+        self.assertTrue(satisfied)
+    
+    def test_all_satisfied(self):
+        satisfied, installed, missing = resolve_dependencies(
+            {"requires": ["json"]}, auto_install=False
+        )
+        self.assertTrue(satisfied)
+    
+    def test_missing_no_auto(self):
+        satisfied, installed, missing = resolve_dependencies(
+            {"requires": ["nonexistent_xyz"]}, auto_install=False
+        )
+        self.assertFalse(satisfied)
+        self.assertIn("nonexistent_xyz", missing)
+
+
+if __name__ == "__main__":
+    unittest.main()

tools/skill_deps.py

@@ -0,0 +1,185 @@
+"""
+Skill Dependency Resolver — Auto-install missing dependencies
+
+Checks skill frontmatter for `requires` field and ensures
+dependencies are installed before loading the skill.
+
+Issue: #754
+"""
+
+import importlib
+import logging
+import subprocess
+import sys
+from typing import Any, Dict, List, Optional, Tuple
+
+logger = logging.getLogger(__name__)
+
+
+def parse_requires(frontmatter: Dict[str, Any]) -> List[str]:
+    """
+    Parse the `requires` field from skill frontmatter.
+    
+    Supports:
+    - requires: [package1, package2]
+    - requires: package1
+    - requires:
+        - package1
+        - package2
+    """
+    requires = frontmatter.get("requires", [])
+    if isinstance(requires, str):
+        return [requires]
+    if isinstance(requires, list):
+        return [str(r) for r in requires if r]
+    return []
+
+
+def check_dependency(package: str) -> Tuple[bool, str]:
+    """
+    Check if a Python package is installed.
+    
+    Returns:
+        Tuple of (is_installed, version_or_error)
+    """
+    # Handle pip package names (e.g., "matrix-nio[e2e]")
+    import_name = package.split("[")[0].replace("-", "_")
+    
+    try:
+        mod = importlib.import_module(import_name)
+        version = getattr(mod, "__version__", "installed")
+        return True, version
+    except ImportError:
+        return False, "not installed"
+
+
+def check_dependencies(requires: List[str]) -> Tuple[List[str], List[str]]:
+    """
+    Check which dependencies are missing.
+    
+    Returns:
+        Tuple of (installed, missing)
+    """
+    installed = []
+    missing = []
+    
+    for pkg in requires:
+        is_installed, _ = check_dependency(pkg)
+        if is_installed:
+            installed.append(pkg)
+        else:
+            missing.append(pkg)
+    
+    return installed, missing
+
+
+def install_dependency(package: str, quiet: bool = False) -> Tuple[bool, str]:
+    """
+    Install a Python package via pip.
+    
+    Returns:
+        Tuple of (success, output_or_error)
+    """
+    try:
+        cmd = [sys.executable, "-m", "pip", "install", package]
+        result = subprocess.run(
+            cmd,
+            capture_output=True,
+            text=True,
+            timeout=120
+        )
+        
+        if result.returncode == 0:
+            if not quiet:
+                logger.info("Installed %s", package)
+            return True, result.stdout
+        else:
+            logger.error("Failed to install %s: %s", package, result.stderr)
+            return False, result.stderr
+    
+    except subprocess.TimeoutExpired:
+        return False, "Installation timed out"
+    except Exception as e:
+        return False, str(e)
+
+
+def resolve_dependencies(
+    frontmatter: Dict[str, Any],
+    auto_install: bool = False,
+    quiet: bool = False
+) -> Tuple[bool, List[str], List[str]]:
+    """
+    Resolve skill dependencies.
+    
+    Args:
+        frontmatter: Skill frontmatter dict
+        auto_install: If True, install missing deps without asking
+        quiet: If True, suppress output
+    
+    Returns:
+        Tuple of (all_satisfied, installed_now, still_missing)
+    """
+    requires = parse_requires(frontmatter)
+    if not requires:
+        return True, [], []
+    
+    installed, missing = check_dependencies(requires)
+    
+    if not missing:
+        if not quiet:
+            logger.debug("All dependencies satisfied: %s", installed)
+        return True, [], []
+    
+    if not auto_install:
+        if not quiet:
+            logger.warning("Missing dependencies: %s", missing)
+        return False, [], missing
+    
+    # Auto-install missing dependencies
+    installed_now = []
+    still_missing = []
+    
+    for pkg in missing:
+        if not quiet:
+            logger.info("Installing missing dependency: %s", pkg)
+        
+        success, output = install_dependency(pkg, quiet=quiet)
+        if success:
+            installed_now.append(pkg)
+        else:
+            still_missing.append(pkg)
+            logger.error("Failed to install %s: %s", pkg, output[:200])
+    
+    all_satisfied = len(still_missing) == 0
+    return all_satisfied, installed_now, still_missing
+
+
+def check_skill_dependencies(skill_dir) -> Dict[str, Any]:
+    """
+    Check dependencies for a skill directory.
+    
+    Returns:
+        Dict with dependency status
+    """
+    from pathlib import Path
+    
+    skill_md = Path(skill_dir) / "SKILL.md"
+    if not skill_md.exists():
+        return {"requires": [], "installed": [], "missing": [], "satisfied": True}
+    
+    try:
+        content = skill_md.read_text()
+        from agent.skill_utils import parse_frontmatter
+        frontmatter, _ = parse_frontmatter(content)
+    except Exception:
+        return {"requires": [], "installed": [], "missing": [], "satisfied": True}
+    
+    requires = parse_requires(frontmatter)
+    installed, missing = check_dependencies(requires)
+    
+    return {
+        "requires": requires,
+        "installed": installed,
+        "missing": missing,
+        "satisfied": len(missing) == 0
+    }