feat: publish Dever core with project scaffolding and versioned AI skills

.trellis/scripts/common/trellis_config.py

@@ -0,0 +1,239 @@
+#!/usr/bin/env python3
+"""
+Standalone reader for .trellis/config.yaml.
+
+Owns the minimal YAML parser used across Trellis. ``common.config`` imports
+``parse_simple_yaml`` from here rather than keeping its own copy: this module
+imports nothing from the package, so hooks can load it as a single file, and
+one parser cannot drift from another. Returns an empty dict on
+missing/malformed files so callers stay simple.
+
+Supported subset: ``key: value`` scalars (everything is a string), nested
+mappings by indentation, ``- `` lists of scalars, ``#`` comments (whole-line
+and inline outside quotes), and one layer of matching surrounding quotes.
+Constructs outside that subset — block scalars, anchors, aliases, merge keys,
+flow collections, and mappings nested inside a list — are reported on stderr
+and skipped rather than parsed into a plausible-looking wrong value.
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+from typing import Optional
+
+
+CONFIG_REL_PATH = ".trellis/config.yaml"
+
+
+def _unquote(value: str) -> str:
+    if len(value) >= 2 and value[0] == value[-1] and value[0] in ('"', "'"):
+        return value[1:-1]
+    return value
+
+
+def _strip_inline_comment(value: str) -> str:
+    """Strip ` # …` inline comments while preserving `#` inside quoted strings.
+
+    YAML treats ` #` (space-hash) as a comment opener; bare `#` inside a token
+    is part of the value. Quoted strings are immune.
+    """
+    in_quote: str | None = None
+    for idx, ch in enumerate(value):
+        if in_quote:
+            if ch == in_quote:
+                in_quote = None
+            continue
+        if ch in ('"', "'"):
+            in_quote = ch
+            continue
+        if ch == "#" and (idx == 0 or value[idx - 1].isspace()):
+            return value[:idx]
+    return value
+
+
+def _next_content_line(lines: list[str], start: int) -> tuple[int, str]:
+    i = start
+    while i < len(lines):
+        stripped = lines[i].strip()
+        if stripped and not stripped.startswith("#"):
+            return i, lines[i]
+        i += 1
+    return i, ""
+
+
+def _warn_unsupported(source: str, lineno: int, line: str, reason: str) -> None:
+    """Report a YAML construct this parser cannot represent, and move on."""
+    print(
+        f"[WARN] {source}:{lineno}: {reason}; ignoring: {line.strip()}",
+        file=sys.stderr,
+    )
+
+
+def _is_block_scalar(value: str) -> bool:
+    """True for ``|``, ``>`` and their chomping/indent indicators (``|-``, ``>2``)."""
+    if not value or value[0] not in ("|", ">"):
+        return False
+    return all(ch in "+-0123456789" for ch in value[1:])
+
+
+def _unsupported_value(key: str, value: str) -> str | None:
+    """Name the unsupported construct in an unquoted scalar value, else None.
+
+    Only unquoted values are inspected: ``cmd: "[a] | b"`` is a string the user
+    wrote deliberately, while a bare ``notes: |`` or ``base: *anchor`` would
+    otherwise be stored as the literal marker with the real content dropped.
+    """
+    if key == "<<":
+        return "YAML merge keys are not supported"
+    if _is_block_scalar(value):
+        return "block scalars are not supported"
+    if value.startswith("&"):
+        return "YAML anchors are not supported"
+    if value.startswith("*"):
+        return "YAML aliases are not supported"
+    if value.startswith("["):
+        return "flow sequences are not supported (use `- ` list items)"
+    if value.startswith("{"):
+        return "flow mappings are not supported (use an indented mapping)"
+    return None
+
+
+def _skip_indented_body(lines: list[str], start: int, indent: int) -> int:
+    """Skip the continuation lines of a rejected key (block scalar body etc.)."""
+    i = start
+    while i < len(lines):
+        stripped = lines[i].strip()
+        if stripped and len(lines[i]) - len(lines[i].lstrip()) <= indent:
+            break
+        i += 1
+    return i
+
+
+def _parse_yaml_block(
+    lines: list[str], start: int, min_indent: int, target: dict, source: str
+) -> int:
+    i = start
+    current_list: list | None = None
+    # Indent of the key that opened current_list, so a deeper `key: value`
+    # can be recognized as a mapping inside that list.
+    list_owner_indent = 0
+
+    while i < len(lines):
+        line = lines[i]
+        stripped = line.strip()
+
+        if not stripped or stripped.startswith("#"):
+            i += 1
+            continue
+
+        indent = len(line) - len(line.lstrip())
+        if indent < min_indent:
+            break
+
+        if stripped.startswith("- "):
+            if current_list is not None:
+                current_list.append(_unquote(stripped[2:].strip()))
+            i += 1
+        elif ":" in stripped:
+            if current_list is not None and indent > list_owner_indent:
+                # `- name: cli` / `  path: x`: the second key belongs to a
+                # mapping inside the list. Storing it would hoist it into the
+                # parent dict as a sibling of the list — a nested key silently
+                # becoming a root key.
+                _warn_unsupported(
+                    source,
+                    i + 1,
+                    line,
+                    "mappings inside a list are not supported",
+                )
+                i += 1
+                continue
+
+            key, _, value = stripped.partition(":")
+            key = key.strip()
+            value = _strip_inline_comment(value).strip()
+            was_quoted = len(value) >= 2 and value[0] == value[-1] and value[0] in ('"', "'")
+
+            if not was_quoted:
+                reason = _unsupported_value(key, value)
+                if reason is not None:
+                    _warn_unsupported(source, i + 1, line, reason)
+                    current_list = None
+                    i = _skip_indented_body(lines, i + 1, indent)
+                    continue
+
+            value = _unquote(value)
+            current_list = None
+
+            if value or was_quoted:
+                target[key] = value
+                i += 1
+            else:
+                next_i, next_line = _next_content_line(lines, i + 1)
+                if next_i >= len(lines):
+                    target[key] = {}
+                    i = next_i
+                elif next_line.strip().startswith("- "):
+                    current_list = []
+                    list_owner_indent = indent
+                    target[key] = current_list
+                    i += 1
+                else:
+                    next_indent = len(next_line) - len(next_line.lstrip())
+                    if next_indent > indent:
+                        nested: dict = {}
+                        target[key] = nested
+                        i = _parse_yaml_block(lines, i + 1, next_indent, nested, source)
+                    else:
+                        target[key] = {}
+                        i += 1
+        else:
+            i += 1
+
+    return i
+
+
+def parse_simple_yaml(content: str, source: str = "config.yaml") -> dict:
+    """Parse simple YAML with nested dict support (no dependencies).
+
+    Supports:
+        - key: value (string)
+        - key: (followed by list items)
+            - item1
+            - item2
+        - key: (followed by nested dict)
+            nested_key: value
+            nested_key2:
+              - item
+
+    Uses indentation to detect nesting (2+ spaces deeper = child). Every value
+    is a string; consumers coerce. Unsupported constructs are reported on
+    stderr against ``source`` and skipped — see the module docstring.
+
+    Args:
+        content: YAML content string.
+        source: Label used in warnings, normally the config file path.
+
+    Returns:
+        Parsed dict (values can be str, list[str], or dict).
+    """
+    lines = content.splitlines()
+    result: dict = {}
+    _parse_yaml_block(lines, 0, 0, result, source)
+    return result
+
+
+def read_trellis_config(repo_root: Optional[Path] = None) -> dict:
+    """Read .trellis/config.yaml. Returns {} on missing or malformed file."""
+    root = repo_root or Path.cwd()
+    config_file = root / CONFIG_REL_PATH
+    try:
+        content = config_file.read_text(encoding="utf-8")
+    except (FileNotFoundError, OSError):
+        return {}
+    try:
+        parsed = parse_simple_yaml(content, source=str(config_file))
+    except Exception:
+        return {}
+    return parsed if isinstance(parsed, dict) else {}