generated from coulomb/repo-seed
tegwick
715ab1ca00
render_patch(overlay, base_body) → Patch (pure difflib unified diff, target- labelled); is_empty when unchanged. 3 tests green, pyflakes clean. (ADR-05) Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
39 lines
1.1 KiB
Python
39 lines
1.1 KiB
Python
"""Patch rendering — an overlay as a reviewable diff (FederationRequirements ADR-05).
|
|
|
|
A pure function over (base body, overlay body): the auditable change proposal that an overlay
|
|
becomes before it is applied. Markdown/native text in this slice (lossless); a lossy
|
|
native-syntax-with-fidelity-report variant is later (TSD §A.6).
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
import difflib
|
|
from dataclasses import dataclass
|
|
|
|
from shard_wiki.coordination.overlay import Overlay
|
|
from shard_wiki.model import Identity
|
|
|
|
__all__ = ["Patch", "render_patch"]
|
|
|
|
|
|
@dataclass(frozen=True, slots=True)
|
|
class Patch:
|
|
target: Identity
|
|
diff: str
|
|
|
|
@property
|
|
def is_empty(self) -> bool:
|
|
return self.diff == ""
|
|
|
|
|
|
def render_patch(overlay: Overlay, base_body: str) -> Patch:
|
|
"""Render ``base_body`` → ``overlay.body`` as a unified diff against the overlay target."""
|
|
label = str(overlay.target)
|
|
lines = difflib.unified_diff(
|
|
base_body.splitlines(keepends=True),
|
|
overlay.body.splitlines(keepends=True),
|
|
fromfile=f"a/{label}",
|
|
tofile=f"b/{label}",
|
|
)
|
|
return Patch(target=overlay.target, diff="".join(lines))
|