attributes.py
python
| 1 | """Muse attributes — ``.museattributes`` TOML parser and per-path strategy resolver. |
| 2 | |
| 3 | ``.museattributes`` lives in the repository root (next to ``.muse/`` and |
| 4 | ``muse-work/``) and declares merge strategies for specific paths and |
| 5 | dimensions. It uses TOML syntax with an optional ``[meta]`` section for |
| 6 | domain declaration and an ordered ``[[rules]]`` array. |
| 7 | |
| 8 | Format |
| 9 | ------ |
| 10 | |
| 11 | .. code-block:: toml |
| 12 | |
| 13 | # .museattributes |
| 14 | # Merge strategy overrides for this repository. |
| 15 | |
| 16 | [meta] |
| 17 | domain = "midi" # optional — validated against .muse/repo.json |
| 18 | |
| 19 | [[rules]] |
| 20 | path = "drums/*" # fnmatch glob against workspace-relative POSIX paths |
| 21 | dimension = "*" # domain axis name, or "*" to match any dimension |
| 22 | strategy = "ours" |
| 23 | |
| 24 | [[rules]] |
| 25 | path = "keys/*" |
| 26 | dimension = "pitch_bend" |
| 27 | strategy = "theirs" |
| 28 | |
| 29 | [[rules]] |
| 30 | path = "*" |
| 31 | dimension = "*" |
| 32 | strategy = "auto" |
| 33 | |
| 34 | **path** — ``fnmatch`` glob matched against workspace-relative POSIX paths. |
| 35 | **dimension** — a domain-defined axis name (e.g. ``notes``, ``pitch_bend``) |
| 36 | or ``*`` to match any dimension. |
| 37 | **strategy** — one of ``ours | theirs | union | auto | manual``. |
| 38 | |
| 39 | **First matching rule wins.** ``[meta]`` is optional; its absence has no |
| 40 | effect on merge correctness. When both ``[meta] domain`` and a repo |
| 41 | ``domain`` are known, a mismatch logs a warning. |
| 42 | |
| 43 | Public API |
| 44 | ---------- |
| 45 | |
| 46 | - :class:`AttributesMeta` — TypedDict for the ``[meta]`` section. |
| 47 | - :class:`AttributesRuleDict` — TypedDict for a single ``[[rules]]`` entry. |
| 48 | - :class:`MuseAttributesFile` — TypedDict for the full parsed file. |
| 49 | - :class:`AttributeRule` — a single resolved rule (dataclass). |
| 50 | - :func:`read_attributes_meta` — read only the ``[meta]`` section. |
| 51 | - :func:`load_attributes` — read ``.museattributes`` from a repo root. |
| 52 | - :func:`resolve_strategy` — first-match strategy lookup. |
| 53 | """ |
| 54 | from __future__ import annotations |
| 55 | |
| 56 | import fnmatch |
| 57 | import logging |
| 58 | import pathlib |
| 59 | import tomllib |
| 60 | from dataclasses import dataclass |
| 61 | from typing import TypedDict |
| 62 | |
| 63 | _logger = logging.getLogger(__name__) |
| 64 | |
| 65 | VALID_STRATEGIES: frozenset[str] = frozenset( |
| 66 | {"ours", "theirs", "union", "auto", "manual"} |
| 67 | ) |
| 68 | |
| 69 | _FILENAME = ".museattributes" |
| 70 | |
| 71 | |
| 72 | class AttributesMeta(TypedDict, total=False): |
| 73 | """Typed representation of the ``[meta]`` section in ``.museattributes``.""" |
| 74 | |
| 75 | domain: str |
| 76 | |
| 77 | |
| 78 | class AttributesRuleDict(TypedDict): |
| 79 | """Typed representation of a single ``[[rules]]`` entry.""" |
| 80 | |
| 81 | path: str |
| 82 | dimension: str |
| 83 | strategy: str |
| 84 | |
| 85 | |
| 86 | class MuseAttributesFile(TypedDict, total=False): |
| 87 | """Typed representation of the complete ``.museattributes`` file.""" |
| 88 | |
| 89 | meta: AttributesMeta |
| 90 | rules: list[AttributesRuleDict] |
| 91 | |
| 92 | |
| 93 | @dataclass(frozen=True) |
| 94 | class AttributeRule: |
| 95 | """A single rule resolved from ``.museattributes``. |
| 96 | |
| 97 | Attributes: |
| 98 | path_pattern: ``fnmatch`` glob matched against workspace-relative paths. |
| 99 | dimension: Domain axis name (e.g. ``"notes"``) or ``"*"``. |
| 100 | strategy: Resolution strategy: ``ours | theirs | union | auto | manual``. |
| 101 | source_index: 0-based index of the rule in the ``[[rules]]`` array. |
| 102 | """ |
| 103 | |
| 104 | path_pattern: str |
| 105 | dimension: str |
| 106 | strategy: str |
| 107 | source_index: int = 0 |
| 108 | |
| 109 | |
| 110 | def _parse_raw(root: pathlib.Path) -> MuseAttributesFile: |
| 111 | """Read and TOML-parse ``.museattributes``, returning a typed file structure. |
| 112 | |
| 113 | Builds ``MuseAttributesFile`` from the raw TOML dict using explicit |
| 114 | ``isinstance`` checks — no ``Any`` propagated into the return value. |
| 115 | |
| 116 | Raises: |
| 117 | ValueError: On TOML syntax errors. |
| 118 | """ |
| 119 | attr_file = root / _FILENAME |
| 120 | raw_bytes = attr_file.read_bytes() |
| 121 | try: |
| 122 | raw = tomllib.loads(raw_bytes.decode("utf-8")) |
| 123 | except tomllib.TOMLDecodeError as exc: |
| 124 | raise ValueError(f"{_FILENAME}: TOML parse error — {exc}") from exc |
| 125 | |
| 126 | result: MuseAttributesFile = {} |
| 127 | |
| 128 | # [meta] section |
| 129 | meta_raw = raw.get("meta") |
| 130 | if isinstance(meta_raw, dict): |
| 131 | meta: AttributesMeta = {} |
| 132 | domain_val = meta_raw.get("domain") |
| 133 | if isinstance(domain_val, str): |
| 134 | meta["domain"] = domain_val |
| 135 | result["meta"] = meta |
| 136 | |
| 137 | # [[rules]] array |
| 138 | rules_raw = raw.get("rules") |
| 139 | if isinstance(rules_raw, list): |
| 140 | rules: list[AttributesRuleDict] = [] |
| 141 | for idx, entry in enumerate(rules_raw): |
| 142 | if not isinstance(entry, dict): |
| 143 | continue |
| 144 | path_val = entry.get("path") |
| 145 | dim_val = entry.get("dimension") |
| 146 | strat_val = entry.get("strategy") |
| 147 | if ( |
| 148 | isinstance(path_val, str) |
| 149 | and isinstance(dim_val, str) |
| 150 | and isinstance(strat_val, str) |
| 151 | ): |
| 152 | rules.append( |
| 153 | AttributesRuleDict( |
| 154 | path=path_val, |
| 155 | dimension=dim_val, |
| 156 | strategy=strat_val, |
| 157 | ) |
| 158 | ) |
| 159 | else: |
| 160 | missing = [ |
| 161 | f for f, v in (("path", path_val), ("dimension", dim_val), ("strategy", strat_val)) |
| 162 | if not isinstance(v, str) |
| 163 | ] |
| 164 | raise ValueError( |
| 165 | f"{_FILENAME}: rule[{idx}] is missing required field(s): " |
| 166 | + ", ".join(missing) |
| 167 | ) |
| 168 | result["rules"] = rules |
| 169 | |
| 170 | return result |
| 171 | |
| 172 | |
| 173 | def read_attributes_meta(root: pathlib.Path) -> AttributesMeta: |
| 174 | """Return the ``[meta]`` section of ``.museattributes``, or an empty dict. |
| 175 | |
| 176 | Does not validate or resolve rules — use this to inspect metadata only. |
| 177 | |
| 178 | Args: |
| 179 | root: Repository root directory. |
| 180 | |
| 181 | Returns: |
| 182 | The ``[meta]`` TypedDict, which may be empty if the section is absent |
| 183 | or the file does not exist. |
| 184 | """ |
| 185 | attr_file = root / _FILENAME |
| 186 | if not attr_file.exists(): |
| 187 | return {} |
| 188 | try: |
| 189 | parsed = _parse_raw(root) |
| 190 | except ValueError: |
| 191 | return {} |
| 192 | meta = parsed.get("meta") |
| 193 | if meta is None: |
| 194 | return {} |
| 195 | return meta |
| 196 | |
| 197 | |
| 198 | def load_attributes( |
| 199 | root: pathlib.Path, |
| 200 | *, |
| 201 | domain: str | None = None, |
| 202 | ) -> list[AttributeRule]: |
| 203 | """Parse ``.museattributes`` from *root* and return the ordered rule list. |
| 204 | |
| 205 | Args: |
| 206 | root: Repository root directory (the directory that contains ``.muse/`` |
| 207 | and ``muse-work/``). |
| 208 | domain: Optional domain name from the active repository. When provided |
| 209 | and the file contains ``[meta] domain``, a mismatch logs a |
| 210 | warning. Pass ``None`` to skip domain validation. |
| 211 | |
| 212 | Returns: |
| 213 | A list of :class:`AttributeRule` in file order. Returns an empty list |
| 214 | when ``.museattributes`` is absent or contains no valid rules. |
| 215 | |
| 216 | Raises: |
| 217 | ValueError: If a rule entry is missing required fields, or contains an |
| 218 | invalid strategy. |
| 219 | """ |
| 220 | attr_file = root / _FILENAME |
| 221 | if not attr_file.exists(): |
| 222 | return [] |
| 223 | |
| 224 | data = _parse_raw(root) |
| 225 | |
| 226 | # Domain validation |
| 227 | meta = data.get("meta", {}) |
| 228 | file_domain = meta.get("domain") if meta else None |
| 229 | if file_domain and domain and file_domain != domain: |
| 230 | _logger.warning( |
| 231 | "⚠️ %s: [meta] domain %r does not match active repo domain %r — " |
| 232 | "rules may target a different domain", |
| 233 | _FILENAME, |
| 234 | file_domain, |
| 235 | domain, |
| 236 | ) |
| 237 | |
| 238 | raw_rules = data.get("rules", []) |
| 239 | |
| 240 | rules: list[AttributeRule] = [] |
| 241 | for idx, entry in enumerate(raw_rules): |
| 242 | strategy = entry["strategy"] |
| 243 | if strategy not in VALID_STRATEGIES: |
| 244 | raise ValueError( |
| 245 | f"{_FILENAME}: rule[{idx}]: unknown strategy {strategy!r}. " |
| 246 | f"Valid strategies: {sorted(VALID_STRATEGIES)}" |
| 247 | ) |
| 248 | |
| 249 | rules.append( |
| 250 | AttributeRule( |
| 251 | path_pattern=entry["path"], |
| 252 | dimension=entry["dimension"], |
| 253 | strategy=strategy, |
| 254 | source_index=idx, |
| 255 | ) |
| 256 | ) |
| 257 | |
| 258 | return rules |
| 259 | |
| 260 | |
| 261 | def resolve_strategy( |
| 262 | rules: list[AttributeRule], |
| 263 | path: str, |
| 264 | dimension: str = "*", |
| 265 | ) -> str: |
| 266 | """Return the first matching strategy for *path* and *dimension*. |
| 267 | |
| 268 | Matching rules: |
| 269 | |
| 270 | - **path**: ``fnmatch.fnmatch(path, rule.path_pattern)`` must be ``True``. |
| 271 | - **dimension**: ``rule.dimension`` must be ``"*"`` (matches anything) **or** |
| 272 | equal *dimension*. |
| 273 | |
| 274 | First-match wins. Returns ``"auto"`` when no rule matches. |
| 275 | |
| 276 | Args: |
| 277 | rules: Rule list from :func:`load_attributes`. |
| 278 | path: Workspace-relative POSIX path (e.g. ``"tracks/drums.mid"``). |
| 279 | dimension: Domain axis name or ``"*"`` to match any rule dimension. |
| 280 | |
| 281 | Returns: |
| 282 | A strategy string: ``"ours"``, ``"theirs"``, ``"union"``, ``"auto"``, |
| 283 | or ``"manual"``. |
| 284 | """ |
| 285 | for rule in rules: |
| 286 | path_match = fnmatch.fnmatch(path, rule.path_pattern) |
| 287 | dim_match = rule.dimension == "*" or rule.dimension == dimension or dimension == "*" |
| 288 | if path_match and dim_match: |
| 289 | return rule.strategy |
| 290 | return "auto" |