diffler_core/
vcs.rs

1//! Backend-agnostic VCS interface. Everything above this trait consumes
2//! `dyn Vcs`; only the `git` module (and test fixtures) may import git2.
3
4use std::path::{Path, PathBuf};
5
6use thiserror::Error;
7
8use crate::model::{DiffModel, HunkId};
9
10#[derive(Debug, Error)]
11pub enum VcsError {
12    // acceptable for M1; rework when a second backend lands
13    #[error(transparent)]
14    Git(#[from] git2::Error),
15    #[error("repository has no working directory")]
16    NoWorkdir,
17    /// Domain refusal, e.g. discarding a file with staged changes.
18    #[error("{0}")]
19    Rejected(String),
20    #[error(transparent)]
21    Io(#[from] std::io::Error),
22}
23
24#[derive(Debug, Clone, PartialEq, Eq)]
25pub struct HeadInfo {
26    /// Branch shorthand; `None` when HEAD is detached.
27    pub branch: Option<String>,
28    /// Abbreviated commit id; empty on an unborn branch.
29    pub oid7: String,
30    /// First line of the HEAD commit message; empty on an unborn branch.
31    pub subject: String,
32    /// Upstream branch shorthand, if configured.
33    pub upstream: Option<String>,
34}
35
36#[derive(Debug, Clone, PartialEq, Eq)]
37pub struct LogEntry {
38    pub oid: String,
39    pub oid7: String,
40    /// Shorthand names of references pointing at this commit.
41    pub refs: Vec<String>,
42    pub subject: String,
43    pub author: String,
44    pub time_unix: i64,
45}
46
47#[derive(Debug, Clone, PartialEq, Eq)]
48pub struct BranchInfo {
49    pub name: String,
50    pub is_head: bool,
51}
52
53/// A network operation the binary runs by shelling out to the backend's CLI,
54/// so the user's existing auth (SSH agent, credential helper, tokens) applies
55/// without diffler holding any credentials.
56#[derive(Debug, Clone, Copy, PartialEq, Eq)]
57pub enum NetworkOp {
58    Push,
59    PushSetUpstream,
60    Pull,
61    Fetch,
62    FetchAll,
63}
64
65/// Per-area views of the working tree, neogit-style sections.
66#[derive(Debug, Clone, Default)]
67pub struct StatusModel {
68    pub untracked: DiffModel,
69    pub unstaged: DiffModel,
70    pub staged: DiffModel,
71}
72
73pub trait Vcs: Send {
74    /// Resolved repository metadata directory. In a plain repo this is
75    /// `<root>/.git`; in a linked worktree `<root>/.git` is a gitlink file
76    /// and this resolves to the external gitdir it points at.
77    fn git_dir(&self) -> Result<PathBuf, VcsError>;
78    /// Current branch, commit, and upstream.
79    fn head(&self) -> Result<HeadInfo, VcsError>;
80    /// Untracked / unstaged / staged sections as separate diff models.
81    fn status(&self) -> Result<StatusModel, VcsError>;
82    /// HEAD vs workdir+index including untracked files: the review view.
83    fn working_tree_diff(&self) -> Result<DiffModel, VcsError>;
84    /// Changes a single commit introduced over its first parent.
85    fn commit_diff(&self, oid: &str) -> Result<DiffModel, VcsError>;
86    /// Combined diff of a contiguous commit range, from the first parent of
87    /// `oldest` to `newest` (`git diff <oldest>^..<newest>` semantics). When
88    /// `oldest` is a root commit its first-parent tree is the empty tree, so
89    /// the range includes everything `oldest` introduced.
90    fn range_diff(&self, oldest_oid: &str, newest_oid: &str) -> Result<DiffModel, VcsError>;
91    /// Diff between two trees as-is (`git diff <base> <newest>` semantics);
92    /// with `base` a merge base this is a PR-style three-dot diff.
93    fn tree_diff(&self, base_oid: &str, newest_oid: &str) -> Result<DiffModel, VcsError>;
94    /// Best common ancestor of two commits.
95    fn merge_base(&self, a: &str, b: &str) -> Result<String, VcsError>;
96    /// Resolve a revision (oid, ref name, remote ref) to a full commit oid.
97    fn resolve(&self, revision: &str) -> Result<String, VcsError>;
98    /// History from HEAD, newest first.
99    fn log(&self, limit: usize) -> Result<Vec<LogEntry>, VcsError>;
100    /// Local branches.
101    fn branches(&self) -> Result<Vec<BranchInfo>, VcsError>;
102    /// Stage a whole file (worktree deletions become staged deletions).
103    fn stage(&self, rel: &Path) -> Result<(), VcsError>;
104    /// Stage one hunk out of the unstaged (or untracked) changes of a file.
105    fn stage_hunk(&self, rel: &Path, hunk: &HunkId) -> Result<(), VcsError>;
106    /// Reset a file's index entry back to HEAD, keeping the worktree.
107    fn unstage(&self, rel: &Path) -> Result<(), VcsError>;
108    /// Remove one staged hunk from the index, keeping the worktree.
109    fn unstage_hunk(&self, rel: &Path, hunk: &HunkId) -> Result<(), VcsError>;
110    /// Throw away worktree changes only; an untracked file is deleted.
111    /// Refused while the file has staged changes (unstage first).
112    fn discard(&self, rel: &Path) -> Result<(), VcsError>;
113    /// Commit the index; returns the new commit id.
114    fn commit(&self, message: &str) -> Result<String, VcsError>;
115    /// Full message of the HEAD commit, for amend/reword editor templates.
116    fn head_message(&self) -> Result<String, VcsError>;
117    /// Amend HEAD, returning the new commit id. `message` `None` reuses HEAD's
118    /// message (extend); `Some` rewords it. `use_index` true folds the staged
119    /// index into the new tree (extend/amend); false keeps HEAD's tree (a
120    /// pure reword). Local-only — no network.
121    fn amend(&self, message: Option<&str>, use_index: bool) -> Result<String, VcsError>;
122    fn create_branch(&self, name: &str, checkout: bool) -> Result<(), VcsError>;
123    /// Refused for the currently checked-out branch.
124    fn delete_branch(&self, name: &str) -> Result<(), VcsError>;
125    fn checkout(&self, name: &str) -> Result<(), VcsError>;
126    /// Stash tracked changes (staged + unstaged), reverting the worktree to
127    /// HEAD; untracked files are left in place, matching `git stash`. `message`
128    /// `None` lets the backend label it. Local-only — no network.
129    fn stash_push(&self, message: Option<&str>) -> Result<(), VcsError>;
130    /// Restore the most recent stash and drop it. Refused when there is no
131    /// stash or the pop would conflict.
132    fn stash_pop(&self) -> Result<(), VcsError>;
133    /// Argv to run for a network op, e.g. `["git", "push"]`. The binary runs
134    /// this in [`Vcs::workdir`] so the backend's own CLI handles credentials;
135    /// diffler never touches them. A future jj backend returns `["jj", …]`.
136    fn network_argv(&self, op: NetworkOp) -> Vec<String>;
137    /// Working directory to run [`Vcs::network_argv`] in.
138    fn workdir(&self) -> Result<PathBuf, VcsError>;
139    /// URL of the named remote (e.g. `origin`), if it exists. Used to detect the
140    /// CI provider's host without shelling out.
141    fn remote_url(&self, name: &str) -> Result<Option<String>, VcsError>;
142    /// Names of every configured remote, for multi-remote CI detection.
143    fn remotes(&self) -> Result<Vec<String>, VcsError>;
144}
diffler_core/vcs.rs

diffler_core/
vcs.rs
