refactor(agent): streamline hook method calls and enhance error logging

- Introduced a helper method `_for_each_hook_safe` to reduce code duplication in hook method implementations.
- Updated error logging to include the method name for better traceability.
- Improved the `SkillsLoader` class by adding a new method `_skill_entries_from_dir` to simplify skill listing logic.
- Enhanced skill loading and filtering logic, ensuring workspace skills take precedence over built-in ones.
- Added comprehensive tests for `SkillsLoader` to validate functionality and edge cases.

nanobot/agent/hook.py

@@ -67,40 +67,27 @@ class CompositeHook(AgentHook):
     def wants_streaming(self) -> bool:
         return any(h.wants_streaming() for h in self._hooks)
 
-    async def before_iteration(self, context: AgentHookContext) -> None:
+    async def _for_each_hook_safe(self, method_name: str, *args: Any, **kwargs: Any) -> None:
         for h in self._hooks:
             try:
-                await h.before_iteration(context)
+                await getattr(h, method_name)(*args, **kwargs)
             except Exception:
-                logger.exception("AgentHook.before_iteration error in {}", type(h).__name__)
+                logger.exception("AgentHook.{} error in {}", method_name, type(h).__name__)
+
+    async def before_iteration(self, context: AgentHookContext) -> None:
+        await self._for_each_hook_safe("before_iteration", context)
 
     async def on_stream(self, context: AgentHookContext, delta: str) -> None:
-        for h in self._hooks:
-            try:
-                await h.on_stream(context, delta)
-            except Exception:
-                logger.exception("AgentHook.on_stream error in {}", type(h).__name__)
+        await self._for_each_hook_safe("on_stream", context, delta)
 
     async def on_stream_end(self, context: AgentHookContext, *, resuming: bool) -> None:
-        for h in self._hooks:
-            try:
-                await h.on_stream_end(context, resuming=resuming)
-            except Exception:
-                logger.exception("AgentHook.on_stream_end error in {}", type(h).__name__)
+        await self._for_each_hook_safe("on_stream_end", context, resuming=resuming)
 
     async def before_execute_tools(self, context: AgentHookContext) -> None:
-        for h in self._hooks:
-            try:
-                await h.before_execute_tools(context)
-            except Exception:
-                logger.exception("AgentHook.before_execute_tools error in {}", type(h).__name__)
+        await self._for_each_hook_safe("before_execute_tools", context)
 
     async def after_iteration(self, context: AgentHookContext) -> None:
-        for h in self._hooks:
-            try:
-                await h.after_iteration(context)
-            except Exception:
-                logger.exception("AgentHook.after_iteration error in {}", type(h).__name__)
+        await self._for_each_hook_safe("after_iteration", context)
 
     def finalize_content(self, context: AgentHookContext, content: str | None) -> str | None:
         for h in self._hooks:

nanobot/agent/skills.py

@@ -9,6 +9,16 @@ from pathlib import Path
 # Default builtin skills directory (relative to this file)
 BUILTIN_SKILLS_DIR = Path(__file__).parent.parent / "skills"
 
+# Opening ---, YAML body (group 1), closing --- on its own line; supports CRLF.
+_STRIP_SKILL_FRONTMATTER = re.compile(
+    r"^---\s*\r?\n(.*?)\r?\n---\s*\r?\n?",
+    re.DOTALL,
+)
+
+
+def _escape_xml(text: str) -> str:
+    return text.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
+
 
 class SkillsLoader:
     """
@@ -23,6 +33,22 @@ class SkillsLoader:
         self.workspace_skills = workspace / "skills"
         self.builtin_skills = builtin_skills_dir or BUILTIN_SKILLS_DIR
 
+    def _skill_entries_from_dir(self, base: Path, source: str, *, skip_names: set[str] | None = None) -> list[dict[str, str]]:
+        if not base.exists():
+            return []
+        entries: list[dict[str, str]] = []
+        for skill_dir in base.iterdir():
+            if not skill_dir.is_dir():
+                continue
+            skill_file = skill_dir / "SKILL.md"
+            if not skill_file.exists():
+                continue
+            name = skill_dir.name
+            if skip_names is not None and name in skip_names:
+                continue
+            entries.append({"name": name, "path": str(skill_file), "source": source})
+        return entries
+
     def list_skills(self, filter_unavailable: bool = True) -> list[dict[str, str]]:
         """
         List all available skills.
@@ -33,27 +59,15 @@ class SkillsLoader:
         Returns:
             List of skill info dicts with 'name', 'path', 'source'.
         """
-        skills = []
-
-        # Workspace skills (highest priority)
-        if self.workspace_skills.exists():
-            for skill_dir in self.workspace_skills.iterdir():
-                if skill_dir.is_dir():
-                    skill_file = skill_dir / "SKILL.md"
-                    if skill_file.exists():
-                        skills.append({"name": skill_dir.name, "path": str(skill_file), "source": "workspace"})
-
-        # Built-in skills
+        skills = self._skill_entries_from_dir(self.workspace_skills, "workspace")
+        workspace_names = {entry["name"] for entry in skills}
         if self.builtin_skills and self.builtin_skills.exists():
-            for skill_dir in self.builtin_skills.iterdir():
-                if skill_dir.is_dir():
-                    skill_file = skill_dir / "SKILL.md"
-                    if skill_file.exists() and not any(s["name"] == skill_dir.name for s in skills):
-                        skills.append({"name": skill_dir.name, "path": str(skill_file), "source": "builtin"})
+            skills.extend(
+                self._skill_entries_from_dir(self.builtin_skills, "builtin", skip_names=workspace_names)
+            )
 
-        # Filter by requirements
         if filter_unavailable:
-            return [s for s in skills if self._check_requirements(self._get_skill_meta(s["name"]))]
+            return [skill for skill in skills if self._check_requirements(self._get_skill_meta(skill["name"]))]
         return skills
 
     def load_skill(self, name: str) -> str | None:
@@ -66,17 +80,13 @@ class SkillsLoader:
         Returns:
             Skill content or None if not found.
         """
-        # Check workspace first
-        workspace_skill = self.workspace_skills / name / "SKILL.md"
-        if workspace_skill.exists():
-            return workspace_skill.read_text(encoding="utf-8")
-
-        # Check built-in
+        roots = [self.workspace_skills]
         if self.builtin_skills:
-            builtin_skill = self.builtin_skills / name / "SKILL.md"
-            if builtin_skill.exists():
-                return builtin_skill.read_text(encoding="utf-8")
-
+            roots.append(self.builtin_skills)
+        for root in roots:
+            path = root / name / "SKILL.md"
+            if path.exists():
+                return path.read_text(encoding="utf-8")
         return None
 
     def load_skills_for_context(self, skill_names: list[str]) -> str:
@@ -89,14 +99,12 @@ class SkillsLoader:
         Returns:
             Formatted skills content.
         """
-        parts = []
-        for name in skill_names:
-            content = self.load_skill(name)
-            if content:
-                content = self._strip_frontmatter(content)
-                parts.append(f"### Skill: {name}\n\n{content}")
-
-        return "\n\n---\n\n".join(parts) if parts else ""
+        parts = [
+            f"### Skill: {name}\n\n{self._strip_frontmatter(markdown)}"
+            for name in skill_names
+            if (markdown := self.load_skill(name))
+        ]
+        return "\n\n---\n\n".join(parts)
 
     def build_skills_summary(self) -> str:
         """
@@ -112,44 +120,36 @@ class SkillsLoader:
         if not all_skills:
             return ""
 
-        def escape_xml(s: str) -> str:
-            return s.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
-
-        lines = ["<skills>"]
-        for s in all_skills:
-            name = escape_xml(s["name"])
-            path = s["path"]
-            desc = escape_xml(self._get_skill_description(s["name"]))
-            skill_meta = self._get_skill_meta(s["name"])
-            available = self._check_requirements(skill_meta)
-
-            lines.append(f"  <skill available=\"{str(available).lower()}\">")
-            lines.append(f"    <name>{name}</name>")
-            lines.append(f"    <description>{desc}</description>")
-            lines.append(f"    <location>{path}</location>")
-
-            # Show missing requirements for unavailable skills
+        lines: list[str] = ["<skills>"]
+        for entry in all_skills:
+            skill_name = entry["name"]
+            meta = self._get_skill_meta(skill_name)
+            available = self._check_requirements(meta)
+            lines.extend(
+                [
+                    f'  <skill available="{str(available).lower()}">',
+                    f"    <name>{_escape_xml(skill_name)}</name>",
+                    f"    <description>{_escape_xml(self._get_skill_description(skill_name))}</description>",
+                    f"    <location>{entry['path']}</location>",
+                ]
+            )
             if not available:
-                missing = self._get_missing_requirements(skill_meta)
+                missing = self._get_missing_requirements(meta)
                 if missing:
-                    lines.append(f"    <requires>{escape_xml(missing)}</requires>")
-
+                    lines.append(f"    <requires>{_escape_xml(missing)}</requires>")
             lines.append("  </skill>")
         lines.append("</skills>")
-
         return "\n".join(lines)
 
     def _get_missing_requirements(self, skill_meta: dict) -> str:
         """Get a description of missing requirements."""
-        missing = []
         requires = skill_meta.get("requires", {})
-        for b in requires.get("bins", []):
-            if not shutil.which(b):
-                missing.append(f"CLI: {b}")
-        for env in requires.get("env", []):
-            if not os.environ.get(env):
-                missing.append(f"ENV: {env}")
-        return ", ".join(missing)
+        required_bins = requires.get("bins", [])
+        required_env_vars = requires.get("env", [])
+        return ", ".join(
+            [f"CLI: {command_name}" for command_name in required_bins if not shutil.which(command_name)]
+            + [f"ENV: {env_name}" for env_name in required_env_vars if not os.environ.get(env_name)]
+        )
 
     def _get_skill_description(self, name: str) -> str:
         """Get the description of a skill from its frontmatter."""
@@ -160,30 +160,32 @@ class SkillsLoader:
 
     def _strip_frontmatter(self, content: str) -> str:
         """Remove YAML frontmatter from markdown content."""
-        if content.startswith("---"):
-            match = re.match(r"^---\n.*?\n---\n", content, re.DOTALL)
-            if match:
-                return content[match.end():].strip()
+        if not content.startswith("---"):
+            return content
+        match = _STRIP_SKILL_FRONTMATTER.match(content)
+        if match:
+            return content[match.end():].strip()
         return content
 
     def _parse_nanobot_metadata(self, raw: str) -> dict:
         """Parse skill metadata JSON from frontmatter (supports nanobot and openclaw keys)."""
         try:
             data = json.loads(raw)
-            return data.get("nanobot", data.get("openclaw", {})) if isinstance(data, dict) else {}
         except (json.JSONDecodeError, TypeError):
             return {}
+        if not isinstance(data, dict):
+            return {}
+        payload = data.get("nanobot", data.get("openclaw", {}))
+        return payload if isinstance(payload, dict) else {}
 
     def _check_requirements(self, skill_meta: dict) -> bool:
         """Check if skill requirements are met (bins, env vars)."""
         requires = skill_meta.get("requires", {})
-        for b in requires.get("bins", []):
-            if not shutil.which(b):
-                return False
-        for env in requires.get("env", []):
-            if not os.environ.get(env):
-                return False
-        return True
+        required_bins = requires.get("bins", [])
+        required_env_vars = requires.get("env", [])
+        return all(shutil.which(cmd) for cmd in required_bins) and all(
+            os.environ.get(var) for var in required_env_vars
+        )
 
     def _get_skill_meta(self, name: str) -> dict:
         """Get nanobot metadata for a skill (cached in frontmatter)."""
@@ -192,13 +194,15 @@ class SkillsLoader:
 
     def get_always_skills(self) -> list[str]:
         """Get skills marked as always=true that meet requirements."""
-        result = []
-        for s in self.list_skills(filter_unavailable=True):
-            meta = self.get_skill_metadata(s["name"]) or {}
-            skill_meta = self._parse_nanobot_metadata(meta.get("metadata", ""))
-            if skill_meta.get("always") or meta.get("always"):
-                result.append(s["name"])
-        return result
+        return [
+            entry["name"]
+            for entry in self.list_skills(filter_unavailable=True)
+            if (meta := self.get_skill_metadata(entry["name"]) or {})
+            and (
+                self._parse_nanobot_metadata(meta.get("metadata", "")).get("always")
+                or meta.get("always")
+            )
+        ]
 
     def get_skill_metadata(self, name: str) -> dict | None:
         """
@@ -211,18 +215,15 @@ class SkillsLoader:
             Metadata dict or None.
         """
         content = self.load_skill(name)
-        if not content:
+        if not content or not content.startswith("---"):
             return None
-
-        if content.startswith("---"):
-            match = re.match(r"^---\n(.*?)\n---", content, re.DOTALL)
-            if match:
-                # Simple YAML parsing
-                metadata = {}
-                for line in match.group(1).split("\n"):
-                    if ":" in line:
-                        key, value = line.split(":", 1)
-                        metadata[key.strip()] = value.strip().strip('"\'')
-                return metadata
-
-        return None
+        match = _STRIP_SKILL_FRONTMATTER.match(content)
+        if not match:
+            return None
+        metadata: dict[str, str] = {}
+        for line in match.group(1).splitlines():
+            if ":" not in line:
+                continue
+            key, value = line.split(":", 1)
+            metadata[key.strip()] = value.strip().strip('"\'')
+        return metadata