Files
hermes-agent/tools/patch_parser.py

448 lines
20 KiB
Python

#!/usr/bin/env python3
"""V4A patch format parser and applier (format used by codex, cline, etc.).
*** Begin Patch / *** End Patch wrap the operations:
*** Update File: p.py then hunks: ``@@ hint @@``, `` ctx``, ``-old``, ``+new``
*** Add File: n.py then ``+`` lines; *** Delete File: o.py; *** Move File: a -> b
operations, error = parse_v4a_patch(patch_content)
result = apply_v4a_operations(operations, file_ops)
"""
import difflib
import inspect
import re
from dataclasses import dataclass, field
from enum import Enum
from typing import Any, Callable, Dict, List, Optional, Tuple
class OperationType(Enum):
ADD = "add"
UPDATE = "update"
DELETE = "delete"
MOVE = "move"
@dataclass
class HunkLine:
prefix: str # ' ', '-', or '+'
content: str
@dataclass
class Hunk:
context_hint: Optional[str] = None
lines: List[HunkLine] = field(default_factory=list)
@dataclass
class PatchOperation:
operation: OperationType
file_path: str
new_path: Optional[str] = None # MOVE only
hunks: List[Hunk] = field(default_factory=list)
content: Optional[str] = None # ADD only
# Markers must occupy the whole line at column 0 so content lines that merely
# mention the format ("+*** End Patch") can't truncate or reset the patch.
_BEGIN_MARKER = re.compile(r'^\*\*\*\s*Begin\s+Patch\s*$')
_END_MARKER = re.compile(r'^\*\*\*\s*End\s+Patch\s*$')
_OP_MARKERS: List[Tuple[OperationType, re.Pattern]] = [
(OperationType.UPDATE, re.compile(r'\*\*\*\s*Update\s+File:\s*(.+)')),
(OperationType.ADD, re.compile(r'\*\*\*\s*Add\s+File:\s*(.+)')),
(OperationType.DELETE, re.compile(r'\*\*\*\s*Delete\s+File:\s*(.+)')),
(OperationType.MOVE, re.compile(r'\*\*\*\s*Move\s+File:\s*(.+?)\s*->\s*(.+)'))]
_HINT_RE = re.compile(r'@@\s*(.+?)\s*@@')
def parse_v4a_patch(patch_content: str) -> Tuple[List[PatchOperation], Optional[str]]:
"""Parse a V4A patch -> ``(operations, None)`` (``[]`` for an empty patch is not an
error) or ``([], "Parse error: ...")`` for malformed operations."""
# Tolerate CRLF bodies: a stray ``\r`` would otherwise end up in every
# HunkLine.content and defeat the anchored Begin/End markers.
lines = [ln[:-1] if ln.endswith('\r') else ln for ln in patch_content.split('\n')]
start_idx = -1 # parse from the top when no Begin marker is present
end_idx = len(lines)
for i, line in enumerate(lines):
if _BEGIN_MARKER.match(line):
start_idx = i
elif _END_MARKER.match(line):
end_idx = i
break
operations: List[PatchOperation] = []
current_op: Optional[PatchOperation] = None
current_hunk: Optional[Hunk] = None
def _flush_hunk() -> None:
if current_op and current_hunk and current_hunk.lines:
current_op.hunks.append(current_hunk)
def _flush() -> None:
if current_op:
_flush_hunk()
operations.append(current_op)
for line in lines[start_idx + 1:end_idx]:
op_match = next(
((kind, m) for kind, rx in _OP_MARKERS if (m := rx.match(line))), None)
if op_match:
kind, m = op_match
_flush()
current_op = PatchOperation(
operation=kind,
file_path=m.group(1).strip(),
new_path=m.group(2).strip() if kind is OperationType.MOVE else None)
# UPDATE hunks start lazily (at '@@' or the first hunk line); ADD
# collects all '+' lines into one hunk; DELETE/MOVE are complete.
current_hunk = Hunk() if kind is OperationType.ADD else None
if kind in (OperationType.DELETE, OperationType.MOVE):
operations.append(current_op)
current_op = None
elif line.startswith('@@'):
if current_op:
_flush_hunk()
hint_match = _HINT_RE.match(line)
current_hunk = Hunk(context_hint=hint_match.group(1) if hint_match else None)
elif current_op and line:
if current_hunk is None:
current_hunk = Hunk()
if line[0] in '+- ':
current_hunk.lines.append(HunkLine(line[0], line[1:]))
elif line[0] != '\\': # "\ No newline at end of file" marker is skipped
current_hunk.lines.append(HunkLine(' ', line)) # implicit context line
_flush()
parse_errors: List[str] = []
for op in operations:
if not op.file_path:
parse_errors.append("Operation with empty file path")
if op.operation == OperationType.UPDATE and not op.hunks:
parse_errors.append(f"UPDATE {op.file_path!r}: no hunks found")
if op.operation == OperationType.MOVE and not op.new_path:
parse_errors.append(f"MOVE {op.file_path!r}: missing destination path (expected 'src -> dst')")
if parse_errors:
return [], "Parse error: " + "; ".join(parse_errors)
return operations, None
def _count_occurrences(text: str, pattern: str) -> int:
"""Count occurrences of *pattern* in *text*, advancing one char per hit (overlaps count)."""
return sum(1 for i in range(len(text) + 1) if text.startswith(pattern, i))
def _split_hunk(hunk: Hunk) -> Tuple[List[str], List[str]]:
"""``(search_lines, replace_lines)``: context+removed vs context+added."""
search = [l.content for l in hunk.lines if l.prefix in {' ', '-'}]
replace = [l.content for l in hunk.lines if l.prefix in {' ', '+'}]
return search, replace
def _no_match_hint(error: Optional[str], search_pattern: str, content: str) -> str:
"""Best-effort 'Did you mean...' suffix; never lets a hint failure mask the real error."""
try:
from tools.fuzzy_match import format_no_match_hint
return format_no_match_hint(error, 0, search_pattern, content)
except Exception:
return ""
def _hint_ambiguity(content: str, hint: str, tail: str = "") -> Tuple[int, str]:
"""(occurrences, error) for an addition-only hunk's context hint; error is '' when unique."""
occurrences = _count_occurrences(content, hint)
if occurrences > 1:
return occurrences, (f"context hint '{hint}' is ambiguous "
f"({occurrences} occurrences){tail}")
return occurrences, ""
def _validate_operations(operations: List[PatchOperation], file_ops: Any) -> List[str]:
"""Dry-run every operation; return error strings (empty list = safe to apply). UPDATE
hunks are simulated in order so later hunks see post-earlier-hunk content, as apply will."""
from tools.fuzzy_match import fuzzy_find_and_replace, is_already_applied
errors: List[str] = []
real_change_count = 0
# Virtual overlay so inter-op state validates (e.g. a MOVE creating the destination
# a later UPDATE targets): path -> content from an earlier op; paths MOVE/DELETE removed.
pending_content: dict = {}
removed_paths: set = set()
def _read(path: str):
if path in removed_paths and path not in pending_content:
return None, "file not found"
if path in pending_content:
return pending_content[path], None
r = file_ops.read_file_raw(path)
return (None, r.error) if r.error else (r.content, None)
def _validate_update(op: PatchOperation) -> None:
nonlocal real_change_count
content, read_err = _read(op.file_path)
if read_err:
errors.append(f"{op.file_path}: {read_err}")
return
simulated = content
for hunk_index, hunk in enumerate(op.hunks, start=1):
search_lines, replace_lines = _split_hunk(hunk)
if not any(l.prefix in '-+' for l in hunk.lines):
# Inert anchor hunk (context only) — models emit these
# between real changes; ignore without failing the patch.
continue
real_change_count += 1
if not search_lines:
# Addition-only hunk: the context hint must be unique.
if hunk.context_hint:
occurrences, ambiguous = _hint_ambiguity(simulated, hunk.context_hint)
if occurrences == 0:
errors.append(f"{op.file_path}: addition-only hunk context hint "
f"'{hunk.context_hint}' not found")
elif ambiguous:
errors.append(f"{op.file_path}: addition-only hunk {ambiguous}")
continue
search_pattern = '\n'.join(search_lines)
replacement = '\n'.join(replace_lines)
if search_lines == replace_lines:
# Identical -/+ lines: apply skips it as a no-op, so
# validation must not reject it with the identical-strings error.
continue
new_simulated, count, _strategy, match_error = fuzzy_find_and_replace(
simulated, search_pattern, replacement, replace_all=False)
if count:
simulated = new_simulated
elif not is_already_applied(simulated or "", search_pattern, replacement):
# Already-applied hunks (edit landed in a prior call) are no-ops so
# multi-hunk patches don't fail wholesale; apply performs the same skip.
label = f"'{hunk.context_hint}'" if hunk.context_hint else "(no hint)"
errors.append(
f"{op.file_path}: hunk {hunk_index} {label} not found"
+ (f" — {match_error}" if match_error else "")
+ _no_match_hint(match_error, search_pattern, simulated))
pending_content[op.file_path] = simulated
for op in operations:
if op.operation == OperationType.UPDATE:
_validate_update(op)
continue
real_change_count += 1
if op.operation == OperationType.DELETE:
_content, read_err = _read(op.file_path)
if read_err:
errors.append(f"{op.file_path}: file not found for deletion")
else:
removed_paths.add(op.file_path)
pending_content.pop(op.file_path, None)
elif op.operation == OperationType.MOVE:
if not op.new_path:
errors.append(f"{op.file_path}: MOVE operation missing destination path")
continue
src_content, src_err = _read(op.file_path)
if src_err:
errors.append(f"{op.file_path}: source file not found for move")
_dst, dst_err = _read(op.new_path)
if not dst_err:
errors.append(f"{op.new_path}: destination already exists — move would overwrite")
# Only a cleanly-validated move updates the overlay.
if not src_err and dst_err:
pending_content[op.new_path] = src_content if src_content is not None else ""
pending_content.pop(op.file_path, None)
removed_paths.add(op.file_path)
# ADD: parent directory creation handled by write_file; no pre-check needed.
if not errors and real_change_count == 0:
errors.append("Patch contains no changes (only context lines were provided)")
return errors
# Every _apply_* returns (success, diff_or_error, lsp_diagnostics, lint_result).
ApplyResult = Tuple[bool, str, Optional[str], Optional[dict]]
def apply_v4a_operations(operations: List[PatchOperation], file_ops: Any) -> 'PatchResult':
"""Validate all operations, then apply them (two-phase, atomic on validation failure).
A phase-2 failure (validate/apply race) is reported with a ``git diff`` note since state
may be inconsistent. ``file_ops`` needs read_file_raw/write_file/delete_file/move_file."""
from tools.file_operations import PatchResult # avoid circular import
validation_errors = _validate_operations(operations, file_ops)
if validation_errors:
return PatchResult(
success=False,
error="Patch validation failed (no files were modified):\n"
+ "\n".join(f" • {e}" for e in validation_errors))
files: Dict[str, List[str]] = {"created": [], "deleted": [], "modified": []}
all_diffs: List[str] = []
# V4A bypasses the WriteResult/PatchResult plumbing that write_file uses,
# so LSP diagnostics and lint must be propagated explicitly per file.
lsp_blocks: List[str] = []
errors: List[str] = []
lint_results: Dict[str, dict] = {}
for op in operations:
try:
handler, verb, bucket = _APPLY_DISPATCH[op.operation]
ok, payload, lsp, lint = handler(op, file_ops)
if not ok:
errors.append(f"Failed to {verb} {op.file_path}: {payload}")
continue
label = op.file_path
if op.operation is OperationType.MOVE:
label = f"{op.file_path} -> {op.new_path}"
files[bucket].append(label)
all_diffs.append(payload)
if lsp:
lsp_blocks.append(lsp)
if lint:
lint_results[op.file_path] = lint
except Exception as e:
errors.append(f"Error processing {op.file_path}: {str(e)}")
# Each LSP block carries its own <diagnostics file="..."> header, so plain
# concatenation keeps per-file attribution.
result_kwargs = dict(
diff='\n'.join(all_diffs),
files_modified=files["modified"], files_created=files["created"], files_deleted=files["deleted"],
lint=lint_results if lint_results else None,
lsp_diagnostics="\n\n".join(lsp_blocks) if lsp_blocks else None)
if errors:
return PatchResult(
success=False,
error="Apply phase failed (state may be inconsistent — run `git diff` to assess):\n"
+ "\n".join(f" • {e}" for e in errors),
**result_kwargs)
return PatchResult(success=True, **result_kwargs)
def _write_file_accepts_pre_content(file_ops: Any) -> bool:
"""True when ``file_ops.write_file`` accepts ``pre_content``. Decided from the signature,
not by catching TypeError around the call, so a TypeError raised *inside* a capable
write_file propagates instead of triggering a duplicate write."""
try:
params = inspect.signature(file_ops.write_file).parameters
except (TypeError, ValueError):
return False
return "pre_content" in params or any(
p.kind is inspect.Parameter.VAR_KEYWORD for p in params.values())
def _apply_add(op: PatchOperation, file_ops: Any) -> ApplyResult:
"""Create a file from the hunks' '+' lines."""
content_lines = [line.content for hunk in op.hunks for line in hunk.lines if line.prefix == '+']
result = file_ops.write_file(op.file_path, '\n'.join(content_lines))
if result.error:
return False, result.error, None, None
diff = f"--- /dev/null\n+++ b/{op.file_path}\n" + '\n'.join(f"+{line}" for line in content_lines)
return True, diff, getattr(result, "lsp_diagnostics", None), getattr(result, "lint", None)
def _apply_delete(op: PatchOperation, file_ops: Any) -> ApplyResult:
"""Delete a file, producing a real unified diff of the removed content."""
# Validation already confirmed existence; the re-read guards against races.
read_result = file_ops.read_file_raw(op.file_path)
if read_result.error:
return False, f"Cannot delete {op.file_path}: file not found", None, None
result = file_ops.delete_file(op.file_path)
if result.error:
return False, result.error, None, None
diff = ''.join(difflib.unified_diff(
read_result.content.splitlines(keepends=True), [],
fromfile=f"a/{op.file_path}", tofile="/dev/null"))
return True, diff or f"# Deleted: {op.file_path}", None, None
def _apply_move(op: PatchOperation, file_ops: Any) -> ApplyResult:
result = file_ops.move_file(op.file_path, op.new_path)
if result.error:
return False, result.error, None, None
return True, f"# Moved: {op.file_path} -> {op.new_path}", None, None
def _insert_addition_only(new_content: str, hunk: Hunk, insert_text: str) -> Tuple[Optional[str], Optional[str]]:
"""Place an addition-only hunk after its context hint (or at EOF). Returns (content, error)."""
if hunk.context_hint:
occurrences, ambiguous = _hint_ambiguity(
new_content, hunk.context_hint, " — provide a more unique hint")
if ambiguous:
return None, f"Addition-only hunk: {ambiguous}"
if occurrences == 1:
eol = new_content.find('\n', new_content.find(hunk.context_hint))
if eol != -1:
return new_content[:eol + 1] + insert_text + '\n' + new_content[eol + 1:], None
return new_content + '\n' + insert_text, None
# Hint not found — append at end as a safe fallback.
return new_content.rstrip('\n') + '\n' + insert_text + '\n', None
def _apply_update(op: PatchOperation, file_ops: Any) -> ApplyResult:
"""Apply each hunk via fuzzy replace, then write once."""
from tools.fuzzy_match import fuzzy_find_and_replace, is_already_applied
# Raw read: no line-number prefixes or per-line truncation.
read_result = file_ops.read_file_raw(op.file_path)
if read_result.error:
return False, f"Cannot read file: {read_result.error}", None, None
current_content = read_result.content
new_content = current_content
for hunk in op.hunks:
search_lines, replace_lines = _split_hunk(hunk)
if search_lines and search_lines == replace_lines:
continue
if not search_lines:
new_content, err = _insert_addition_only(new_content, hunk, '\n'.join(replace_lines))
if err:
return False, err, None, None
continue
search_pattern = '\n'.join(search_lines)
replacement = '\n'.join(replace_lines)
new_content, count, _strategy, error = fuzzy_find_and_replace(
new_content, search_pattern, replacement, replace_all=False)
if not (error and count == 0):
continue
# Retry inside a window around the context hint, if any.
hint_pos = new_content.find(hunk.context_hint) if hunk.context_hint else -1
if hint_pos != -1:
window_start = max(0, hint_pos - 500)
window_end = min(len(new_content), hint_pos + 2000)
window_new, count, _strategy, error = fuzzy_find_and_replace(
new_content[window_start:window_end], search_pattern, replacement, replace_all=False
)
if count > 0:
new_content = new_content[:window_start] + window_new + new_content[window_end:]
error = None
if error:
# Mirror the validation-phase already-applied skip, or the two
# phases disagree and the whole patch fails here.
if is_already_applied(new_content, search_pattern, replacement):
continue
return False, f"Could not apply hunk: {error}" + _no_match_hint(error, search_pattern, new_content), None, None
# Pass pre_content to skip a redundant re-read inside write_file when supported.
if _write_file_accepts_pre_content(file_ops):
write_result = file_ops.write_file(op.file_path, new_content, pre_content=current_content)
else:
write_result = file_ops.write_file(op.file_path, new_content)
if write_result.error:
return False, write_result.error, None, None
diff = ''.join(difflib.unified_diff(
current_content.splitlines(keepends=True), new_content.splitlines(keepends=True),
fromfile=f"a/{op.file_path}", tofile=f"b/{op.file_path}"))
return True, diff, getattr(write_result, "lsp_diagnostics", None), getattr(write_result, "lint", None)
# operation -> (handler, verb for error text, files_* bucket)
_APPLY_DISPATCH: Dict[OperationType, Tuple[Callable[[PatchOperation, Any], ApplyResult], str, str]] = {
OperationType.ADD: (_apply_add, "add", "created"),
OperationType.DELETE: (_apply_delete, "delete", "deleted"),
OperationType.MOVE: (_apply_move, "move", "modified"),
OperationType.UPDATE: (_apply_update, "update", "modified"),
}