truth_mirror/
hooks.rs

1//! Hook installation, uninstallation, and dry-run planning.
2
3use std::{
4    fs,
5    io::{self, Read},
6    path::{Path, PathBuf},
7    process::{Command, ExitCode},
8};
9
10use anyhow::{Context, Result, bail};
11
12use crate::{
13    claim,
14    cli::{self, Agent, HookName},
15    gate,
16    reviewer::ReviewQueue,
17    surface::{self, SurfacePlan},
18};
19
20const INSTALLED_HOOKS: &[HookName] =
21    &[HookName::CommitMsg, HookName::PostCommit, HookName::PrePush];
22
23pub fn run(args: cli::InstallHooksArgs, state_dir: &Path) -> Result<ExitCode> {
24    let repo_root = git_root()?;
25    let hooks_path = repo_root.join(state_dir).join("hooks");
26    let plan = HookInstallPlan::new(&repo_root, &hooks_path, args.uninstall);
27    let agents = surface_agents(&args);
28
29    if args.dry_run {
30        println!("{}", plan.render());
31        for agent in &agents {
32            println!(
33                "surface: {} -> {}",
34                surface::agent_slug(*agent),
35                surface::surface_relative_path(*agent)
36            );
37        }
38        return Ok(ExitCode::SUCCESS);
39    }
40
41    if args.uninstall {
42        uninstall(&plan)?;
43        for agent in &agents {
44            SurfacePlan::for_agent(&repo_root, *agent).uninstall()?;
45        }
46    } else {
47        install(&plan)?;
48        for agent in &agents {
49            SurfacePlan::for_agent(&repo_root, *agent).install()?;
50        }
51    }
52
53    Ok(ExitCode::SUCCESS)
54}
55
56/// Agents whose reinjection surface this invocation touches. Install acts only on
57/// explicitly selected agents; uninstall with no selection clears all surfaces so
58/// a bare `install-hooks --uninstall` fully reverses a prior per-agent install.
59fn surface_agents(args: &cli::InstallHooksArgs) -> Vec<Agent> {
60    let mut agents = Vec::new();
61    if args.claude {
62        agents.push(Agent::Claude);
63    }
64    if args.codex {
65        agents.push(Agent::Codex);
66    }
67    if args.pi {
68        agents.push(Agent::Pi);
69    }
70
71    if agents.is_empty() && args.uninstall {
72        return surface::ALL_AGENTS.to_vec();
73    }
74    agents
75}
76
77pub fn dispatch(args: cli::HookDispatchArgs, state_dir: &Path) -> Result<ExitCode> {
78    run_chained_hook(state_dir, args.hook, &args.args)?;
79
80    match args.hook {
81        HookName::CommitMsg => dispatch_commit_msg(state_dir, &args.args)?,
82        HookName::PostCommit => dispatch_post_commit(state_dir)?,
83        HookName::PrePush => dispatch_pre_push(state_dir)?,
84    }
85
86    Ok(ExitCode::SUCCESS)
87}
88
89#[derive(Clone, Debug, Eq, PartialEq)]
90pub struct HookInstallPlan {
91    pub repo_root: PathBuf,
92    pub hooks_path: PathBuf,
93    pub uninstall: bool,
94}
95
96impl HookInstallPlan {
97    pub fn new(repo_root: &Path, hooks_path: &Path, uninstall: bool) -> Self {
98        Self {
99            repo_root: repo_root.to_path_buf(),
100            hooks_path: hooks_path.to_path_buf(),
101            uninstall,
102        }
103    }
104
105    pub fn render(&self) -> String {
106        let action = if self.uninstall {
107            "uninstall"
108        } else {
109            "install"
110        };
111        let hooks = INSTALLED_HOOKS
112            .iter()
113            .map(|hook| hook.as_str())
114            .collect::<Vec<_>>()
115            .join(", ");
116        format!(
117            "truth-mirror hook plan\nrepo={}\naction={action}\nhooksPath={}\nhooks={hooks}",
118            self.repo_root.display(),
119            self.hooks_path.display()
120        )
121    }
122}
123
124pub fn render_shim(hook: HookName) -> String {
125    format!(
126        "#!/bin/sh\nexec truth-mirror hook-dispatch {} \"$@\"\n",
127        hook.as_str()
128    )
129}
130
131fn install(plan: &HookInstallPlan) -> Result<()> {
132    fs::create_dir_all(&plan.hooks_path)?;
133    fs::create_dir_all(plan.hooks_path.join("chained"))?;
134    let git_hooks = plan.repo_root.join(".git/hooks");
135
136    for hook in INSTALLED_HOOKS {
137        let existing = git_hooks.join(hook.as_str());
138        if existing.is_file() {
139            let chained = plan.hooks_path.join("chained").join(hook.as_str());
140            fs::copy(&existing, chained)?;
141        }
142
143        let hook_path = plan.hooks_path.join(hook.as_str());
144        fs::write(&hook_path, render_shim(*hook))?;
145        make_executable(&hook_path)?;
146    }
147
148    git_config(&["config", "core.hooksPath", &path_for_git(&plan.hooks_path)])?;
149    Ok(())
150}
151
152fn uninstall(plan: &HookInstallPlan) -> Result<()> {
153    let _ = Command::new("git")
154        .args(["config", "--unset", "core.hooksPath"])
155        .current_dir(&plan.repo_root)
156        .status();
157
158    if plan.hooks_path.exists() {
159        fs::remove_dir_all(&plan.hooks_path)?;
160    }
161    Ok(())
162}
163
164fn dispatch_commit_msg(state_dir: &Path, args: &[String]) -> Result<()> {
165    let commit_msg_path = args
166        .first()
167        .context("commit-msg hook requires COMMIT_EDITMSG path")?;
168    let commit_message = fs::read_to_string(commit_msg_path)?;
169    let diff = git_stdout(&["diff", "--cached"])?;
170    let claim_file = fs::read_to_string(state_dir.join("claim.txt")).ok();
171    claim::evaluate_commit_message(&commit_message, claim_file.as_deref(), Some(&diff), &[])?;
172    Ok(())
173}
174
175fn dispatch_post_commit(state_dir: &Path) -> Result<()> {
176    let sha = git_stdout(&["rev-parse", "HEAD"])?;
177    ReviewQueue::new(state_dir).enqueue(sha.trim())?;
178    Ok(())
179}
180
181fn dispatch_pre_push(state_dir: &Path) -> Result<()> {
182    let mut stdin = String::new();
183    io::stdin().read_to_string(&mut stdin)?;
184    for line in stdin.lines() {
185        if let Some(range) = pre_push_range_from_line(line) {
186            gate::run(
187                cli::GateArgs {
188                    pre_push: Some(range),
189                    commit_msg: None,
190                    claim_file: None,
191                    diff_file: None,
192                    fake_markers: Vec::new(),
193                },
194                state_dir,
195            )?;
196        }
197    }
198    Ok(())
199}
200
201fn pre_push_range_from_line(line: &str) -> Option<String> {
202    let parts = line.split_whitespace().collect::<Vec<_>>();
203    let local_sha = parts.get(1)?;
204    let remote_sha = parts.get(3)?;
205    if is_zero_sha(local_sha) {
206        return None;
207    }
208
209    if is_zero_sha(remote_sha) {
210        Some((*local_sha).to_owned())
211    } else {
212        Some(format!("{remote_sha}..{local_sha}"))
213    }
214}
215
216fn is_zero_sha(value: &str) -> bool {
217    value.chars().all(|character| character == '0')
218}
219
220fn run_chained_hook(state_dir: &Path, hook: HookName, args: &[String]) -> Result<()> {
221    let chained = state_dir.join("hooks/chained").join(hook.as_str());
222    if !chained.is_file() {
223        return Ok(());
224    }
225
226    let status = Command::new(&chained).args(args).status()?;
227    if !status.success() {
228        bail!(
229            "chained hook {} failed with status {status}",
230            chained.display()
231        );
232    }
233    Ok(())
234}
235
236fn git_root() -> Result<PathBuf> {
237    Ok(PathBuf::from(
238        git_stdout(&["rev-parse", "--show-toplevel"])?.trim(),
239    ))
240}
241
242fn git_stdout(args: &[&str]) -> Result<String> {
243    let output = Command::new("git").args(args).output()?;
244    if !output.status.success() {
245        bail!(
246            "git {} failed: {}",
247            args.join(" "),
248            String::from_utf8_lossy(&output.stderr)
249        );
250    }
251    Ok(String::from_utf8_lossy(&output.stdout).into_owned())
252}
253
254fn git_config(args: &[&str]) -> Result<()> {
255    let status = Command::new("git").args(args).status()?;
256    if !status.success() {
257        bail!("git {} failed with status {status}", args.join(" "));
258    }
259    Ok(())
260}
261
262fn path_for_git(path: &Path) -> String {
263    path.to_string_lossy().into_owned()
264}
265
266#[cfg(unix)]
267fn make_executable(path: &Path) -> Result<()> {
268    use std::os::unix::fs::PermissionsExt;
269
270    let mut permissions = fs::metadata(path)?.permissions();
271    permissions.set_mode(0o755);
272    fs::set_permissions(path, permissions)?;
273    Ok(())
274}
275
276#[cfg(not(unix))]
277fn make_executable(_path: &Path) -> Result<()> {
278    Ok(())
279}
280
281#[cfg(test)]
282mod tests {
283    use proptest::prelude::*;
284
285    use super::{HookInstallPlan, pre_push_range_from_line, render_shim};
286    use crate::cli::HookName;
287
288    #[test]
289    fn hook_shim_is_only_exec_delegation() {
290        let shim = render_shim(HookName::CommitMsg);
291        let lines = shim.lines().collect::<Vec<_>>();
292
293        assert_eq!(lines.len(), 2);
294        assert_eq!(lines[0], "#!/bin/sh");
295        assert_eq!(
296            lines[1],
297            "exec truth-mirror hook-dispatch commit-msg \"$@\""
298        );
299    }
300
301    #[test]
302    fn dry_run_plan_names_hooks_and_hooks_path() {
303        let plan = HookInstallPlan::new(
304            std::path::Path::new("/repo"),
305            std::path::Path::new("/repo/.truth-mirror/hooks"),
306            false,
307        );
308        let rendered = plan.render();
309
310        assert!(rendered.contains("commit-msg"));
311        assert!(rendered.contains("post-commit"));
312        assert!(rendered.contains("pre-push"));
313        assert!(rendered.contains("hooksPath=/repo/.truth-mirror/hooks"));
314    }
315
316    #[test]
317    fn pre_push_line_maps_to_git_range() {
318        let line = "refs/heads/main abc123 refs/heads/main def456";
319
320        assert_eq!(
321            pre_push_range_from_line(line),
322            Some("def456..abc123".to_owned())
323        );
324    }
325
326    proptest! {
327        #[test]
328        fn hook_shim_rendering_stays_tiny_exec_only(index in 0usize..3) {
329            let hook = [HookName::CommitMsg, HookName::PostCommit, HookName::PrePush][index];
330            let shim = render_shim(hook);
331            let lines = shim.lines().collect::<Vec<_>>();
332
333            prop_assert_eq!(lines.len(), 2);
334            prop_assert_eq!(lines[0], "#!/bin/sh");
335            prop_assert!(lines[1].starts_with("exec truth-mirror hook-dispatch "));
336            prop_assert!(lines[1].contains(hook.as_str()));
337        }
338    }
339}
truth_mirror/hooks.rs

truth_mirror/
hooks.rs
