merge.py
python
| 1 | """muse merge — three-way merge a branch into the current branch. |
| 2 | |
| 3 | Algorithm |
| 4 | --------- |
| 5 | 1. Find the merge base (LCA) of HEAD and the target branch. |
| 6 | 2. Delegate conflict detection and manifest reconciliation to the domain plugin. |
| 7 | 3. If clean → apply merged manifest, write new commit, advance HEAD. |
| 8 | 4. If conflicts → write conflict markers to the working tree, write |
| 9 | ``.muse/MERGE_STATE.json``, exit non-zero. |
| 10 | """ |
| 11 | |
| 12 | from __future__ import annotations |
| 13 | |
| 14 | import datetime |
| 15 | import json |
| 16 | import logging |
| 17 | import pathlib |
| 18 | import typer |
| 19 | |
| 20 | from muse.core.errors import ExitCode |
| 21 | from muse.core.merge_engine import ( |
| 22 | find_merge_base, |
| 23 | write_merge_state, |
| 24 | ) |
| 25 | from muse.core.repo import require_repo |
| 26 | from muse.core.snapshot import compute_commit_id, compute_snapshot_id |
| 27 | from muse.core.store import ( |
| 28 | CommitRecord, |
| 29 | SnapshotRecord, |
| 30 | get_head_commit_id, |
| 31 | get_head_snapshot_manifest, |
| 32 | read_commit, |
| 33 | read_current_branch, |
| 34 | read_snapshot, |
| 35 | write_commit, |
| 36 | write_snapshot, |
| 37 | ) |
| 38 | from muse.core.reflog import append_reflog |
| 39 | from muse.core.validation import sanitize_display, validate_branch_name |
| 40 | from muse.core.workdir import apply_manifest |
| 41 | from muse.domain import SnapshotManifest, StructuredMergePlugin |
| 42 | from muse.plugins.registry import read_domain, resolve_plugin |
| 43 | |
| 44 | logger = logging.getLogger(__name__) |
| 45 | |
| 46 | app = typer.Typer() |
| 47 | |
| 48 | |
| 49 | def _read_branch(root: pathlib.Path) -> str: |
| 50 | """Return the current branch name by reading ``.muse/HEAD``.""" |
| 51 | return read_current_branch(root) |
| 52 | |
| 53 | |
| 54 | def _read_repo_id(root: pathlib.Path) -> str: |
| 55 | """Return the repository UUID from ``.muse/repo.json``.""" |
| 56 | return str(json.loads((root / ".muse" / "repo.json").read_text())["repo_id"]) |
| 57 | |
| 58 | |
| 59 | def _restore_from_manifest(root: pathlib.Path, manifest: dict[str, str]) -> None: |
| 60 | """Apply *manifest* to the working tree at *root*. |
| 61 | |
| 62 | Delegates to :func:`muse.core.workdir.apply_manifest` which surgically |
| 63 | removes files no longer present in the target and restores the rest from |
| 64 | the content-addressed object store. |
| 65 | |
| 66 | Args: |
| 67 | root: Repository root (the directory containing ``.muse/``). |
| 68 | manifest: Mapping of POSIX-relative paths to SHA-256 object IDs. |
| 69 | """ |
| 70 | apply_manifest(root, manifest) |
| 71 | |
| 72 | |
| 73 | @app.callback(invoke_without_command=True) |
| 74 | def merge( |
| 75 | ctx: typer.Context, |
| 76 | branch: str = typer.Argument(..., help="Branch to merge into the current branch."), |
| 77 | no_ff: bool = typer.Option(False, "--no-ff", help="Always create a merge commit, even for fast-forward."), |
| 78 | message: str | None = typer.Option(None, "-m", "--message", help="Override the merge commit message."), |
| 79 | ) -> None: |
| 80 | """Three-way merge a branch into the current branch.""" |
| 81 | root = require_repo() |
| 82 | repo_id = _read_repo_id(root) |
| 83 | current_branch = _read_branch(root) |
| 84 | domain = read_domain(root) |
| 85 | plugin = resolve_plugin(root) |
| 86 | |
| 87 | if branch == current_branch: |
| 88 | typer.echo("❌ Cannot merge a branch into itself.") |
| 89 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 90 | |
| 91 | ours_commit_id = get_head_commit_id(root, current_branch) |
| 92 | theirs_commit_id = get_head_commit_id(root, branch) |
| 93 | |
| 94 | if theirs_commit_id is None: |
| 95 | typer.echo(f"❌ Branch '{branch}' has no commits.") |
| 96 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 97 | |
| 98 | if ours_commit_id is None: |
| 99 | typer.echo("❌ Current branch has no commits.") |
| 100 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 101 | |
| 102 | base_commit_id = find_merge_base(root, ours_commit_id, theirs_commit_id) |
| 103 | |
| 104 | if base_commit_id == theirs_commit_id: |
| 105 | typer.echo("Already up to date.") |
| 106 | return |
| 107 | |
| 108 | if base_commit_id == ours_commit_id and not no_ff: |
| 109 | theirs_commit = read_commit(root, theirs_commit_id) |
| 110 | if theirs_commit: |
| 111 | ff_snap = read_snapshot(root, theirs_commit.snapshot_id) |
| 112 | if ff_snap: |
| 113 | _restore_from_manifest(root, ff_snap.manifest) |
| 114 | try: |
| 115 | validate_branch_name(current_branch) |
| 116 | except ValueError as exc: |
| 117 | typer.echo(f"❌ Current branch name is invalid: {exc}") |
| 118 | raise typer.Exit(code=ExitCode.INTERNAL_ERROR) |
| 119 | (root / ".muse" / "refs" / "heads" / current_branch).write_text(theirs_commit_id) |
| 120 | append_reflog( |
| 121 | root, current_branch, old_id=ours_commit_id, new_id=theirs_commit_id, |
| 122 | author="user", |
| 123 | operation=f"merge: fast-forward {sanitize_display(branch)} → {sanitize_display(current_branch)}", |
| 124 | ) |
| 125 | typer.echo(f"Fast-forward to {theirs_commit_id[:8]}") |
| 126 | return |
| 127 | |
| 128 | ours_manifest = get_head_snapshot_manifest(root, repo_id, current_branch) or {} |
| 129 | theirs_manifest = get_head_snapshot_manifest(root, repo_id, branch) or {} |
| 130 | base_manifest: dict[str, str] = {} |
| 131 | if base_commit_id: |
| 132 | base_commit = read_commit(root, base_commit_id) |
| 133 | if base_commit: |
| 134 | base_snap = read_snapshot(root, base_commit.snapshot_id) |
| 135 | if base_snap: |
| 136 | base_manifest = base_snap.manifest |
| 137 | |
| 138 | base_snap_obj = SnapshotManifest(files=base_manifest, domain=domain) |
| 139 | ours_snap_obj = SnapshotManifest(files=ours_manifest, domain=domain) |
| 140 | theirs_snap_obj = SnapshotManifest(files=theirs_manifest, domain=domain) |
| 141 | |
| 142 | # Prefer operation-level merge when the plugin supports it. |
| 143 | # Produces finer-grained conflict detection (sub-file / note level). |
| 144 | # Falls back to file-level merge() for plugins without this capability. |
| 145 | if isinstance(plugin, StructuredMergePlugin): |
| 146 | ours_delta = plugin.diff(base_snap_obj, ours_snap_obj, repo_root=root) |
| 147 | theirs_delta = plugin.diff(base_snap_obj, theirs_snap_obj, repo_root=root) |
| 148 | result = plugin.merge_ops( |
| 149 | base_snap_obj, |
| 150 | ours_snap_obj, |
| 151 | theirs_snap_obj, |
| 152 | ours_delta["ops"], |
| 153 | theirs_delta["ops"], |
| 154 | repo_root=root, |
| 155 | ) |
| 156 | logger.debug( |
| 157 | "merge: used operation-level merge (%s); %d conflict(s)", |
| 158 | type(plugin).__name__, |
| 159 | len(result.conflicts), |
| 160 | ) |
| 161 | else: |
| 162 | result = plugin.merge(base_snap_obj, ours_snap_obj, theirs_snap_obj, repo_root=root) |
| 163 | |
| 164 | # Report any .museattributes auto-resolutions. |
| 165 | if result.applied_strategies: |
| 166 | for p, strategy in sorted(result.applied_strategies.items()): |
| 167 | if strategy == "dimension-merge": |
| 168 | dim_detail = result.dimension_reports.get(p, {}) |
| 169 | dim_summary = ", ".join( |
| 170 | f"{d}={v}" for d, v in sorted(dim_detail.items()) |
| 171 | ) |
| 172 | typer.echo(f" ✔ dimension-merge: {p} ({dim_summary})") |
| 173 | elif strategy != "manual": |
| 174 | typer.echo(f" ✔ [{strategy}] {p}") |
| 175 | |
| 176 | if not result.is_clean: |
| 177 | write_merge_state( |
| 178 | root, |
| 179 | base_commit=base_commit_id or "", |
| 180 | ours_commit=ours_commit_id, |
| 181 | theirs_commit=theirs_commit_id, |
| 182 | conflict_paths=result.conflicts, |
| 183 | other_branch=branch, |
| 184 | ) |
| 185 | typer.echo(f"❌ Merge conflict in {len(result.conflicts)} file(s):") |
| 186 | for p in sorted(result.conflicts): |
| 187 | typer.echo(f" CONFLICT (both modified): {p}") |
| 188 | typer.echo('\nFix conflicts and run "muse commit" to complete the merge.') |
| 189 | raise typer.Exit(code=ExitCode.USER_ERROR) |
| 190 | |
| 191 | merged_manifest = result.merged["files"] |
| 192 | _restore_from_manifest(root, merged_manifest) |
| 193 | |
| 194 | snapshot_id = compute_snapshot_id(merged_manifest) |
| 195 | committed_at = datetime.datetime.now(datetime.timezone.utc) |
| 196 | merge_message = message or f"Merge branch '{branch}' into {current_branch}" |
| 197 | commit_id = compute_commit_id( |
| 198 | parent_ids=[ours_commit_id, theirs_commit_id], |
| 199 | snapshot_id=snapshot_id, |
| 200 | message=merge_message, |
| 201 | committed_at_iso=committed_at.isoformat(), |
| 202 | ) |
| 203 | |
| 204 | write_snapshot(root, SnapshotRecord(snapshot_id=snapshot_id, manifest=merged_manifest)) |
| 205 | write_commit(root, CommitRecord( |
| 206 | commit_id=commit_id, |
| 207 | repo_id=repo_id, |
| 208 | branch=current_branch, |
| 209 | snapshot_id=snapshot_id, |
| 210 | message=merge_message, |
| 211 | committed_at=committed_at, |
| 212 | parent_commit_id=ours_commit_id, |
| 213 | parent2_commit_id=theirs_commit_id, |
| 214 | )) |
| 215 | try: |
| 216 | validate_branch_name(current_branch) |
| 217 | except ValueError as exc: |
| 218 | typer.echo(f"❌ Current branch name is invalid: {exc}") |
| 219 | raise typer.Exit(code=ExitCode.INTERNAL_ERROR) |
| 220 | (root / ".muse" / "refs" / "heads" / current_branch).write_text(commit_id) |
| 221 | |
| 222 | append_reflog( |
| 223 | root, current_branch, old_id=ours_commit_id, new_id=commit_id, |
| 224 | author="user", |
| 225 | operation=f"merge: {sanitize_display(branch)} into {sanitize_display(current_branch)}", |
| 226 | ) |
| 227 | |
| 228 | typer.echo(f"Merged '{sanitize_display(branch)}' into '{sanitize_display(current_branch)}' ({commit_id[:8]})") |