diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml index bc3117d205e97..af1540e7b301d 100644 --- a/helix-term/Cargo.toml +++ b/helix-term/Cargo.toml @@ -13,10 +13,14 @@ repository.workspace = true homepage.workspace = true [features] -default = ["git"] +default = ["vcs"] unicode-lines = ["helix-core/unicode-lines"] integration = ["helix-event/integration_test"] + +# All VCSes available for diffs in Helix +vcs = ["git", "jujutsu"] git = ["helix-vcs/git"] +jujutsu = ["helix-vcs/jujutsu"] [[bin]] name = "hx" diff --git a/helix-vcs/Cargo.toml b/helix-vcs/Cargo.toml index 874b92d03a622..ca4b41bb88df6 100644 --- a/helix-vcs/Cargo.toml +++ b/helix-vcs/Cargo.toml @@ -24,9 +24,13 @@ imara-diff = "0.1.5" anyhow = "1" log = "0.4" +# For `jujutsu` +tempfile = { version = "3.10", optional = true } [features] git = ["gix"] +jujutsu = ["tempfile"] + [dev-dependencies] tempfile = "3.10" diff --git a/helix-vcs/src/jujutsu.rs b/helix-vcs/src/jujutsu.rs new file mode 100644 index 0000000000000..4aa1ed612e75c --- /dev/null +++ b/helix-vcs/src/jujutsu.rs @@ -0,0 +1,117 @@ +//! Jujutsu works with several backends and could add new ones in the future. Private builds of +//! it could also have private backends. Those make it hard to use `jj-lib` since it won't have +//! access to newer or private backends and fail to compute the diffs for them. +//! +//! Instead in case there *is* a diff to base ourselves on, we copy it to a tempfile or just use the +//! current file if not. + +use std::path::Path; +use std::process::Command; +use std::sync::Arc; + +use anyhow::{Context, Result}; +use arc_swap::ArcSwap; + +use crate::DiffProvider; + +pub(super) struct Jujutsu; + +impl DiffProvider for Jujutsu { + fn get_diff_base(&self, file: &Path) -> Result> { + let jj_root_dir = find_jj_root(file)?; + + // We extracted the `jj_root_dir` from the file itself, if stripping the prefix fails + // something has gone very very wrong + let file_rel_to_dot_jj = file + .strip_prefix(jj_root_dir) + .expect("failed to strip diff path from jj root dir"); + + let tmpfile = tempfile::NamedTempFile::with_prefix("helix-jj-diff-") + .context("could not create tempfile to save jj diff base")?; + let tmppath = tmpfile.path(); + + let copy_bin = if cfg!(windows) { "copy.exe" } else { "cp" }; + + let status = Command::new("jj") + .arg("--repository") + .arg(jj_root_dir) + .args(["diff", "--revision", "@", "--config-toml"]) + // Copy the temporary file provided by jujutsu to a temporary path of our own, + // because the `$left` directory is deleted when `jj` finishes executing. + .arg(format!( + "ui.diff.tool = ['{exe}', '$left/{base}', '{target}']", + exe = copy_bin, + base = file_rel_to_dot_jj.display(), + // Where to copy the jujutsu-provided file + target = tmppath.display(), + )) + // Restrict the diff to the current file + .arg(file) + .stdout(std::process::Stdio::null()) + .stderr(std::process::Stdio::null()) + .status() + .context("failed to execute jj diff command")?; + + let use_jj_path = + status.success() && std::fs::metadata(tmppath).map_or(false, |m| m.len() > 0); + // If the copy call inside `jj diff` succeeded, the tempfile is the one containing the base + // else it's just the original file (so no diff). We check for size since `jj` can return + // 0-sized files when there are no diffs to present for the file. + let diff_base_path = if use_jj_path { tmppath } else { file }; + + // If the command succeeded, it means we either copied the jujutsu base or the current file, + // so there should always be something to read and compare to. + std::fs::read(diff_base_path).context("could not read jj diff base from the target") + } + + fn get_current_head_name(&self, file: &Path) -> Result>>> { + let jj_root_dir = find_jj_root(file)?; + + // See + // + // This will produce the following: + // + // - If there are no branches: `vyvqwlmsvnlkmqrvqktpuluvuknuxpmm` + // - If there is a single branch: `vyvqwlmsvnlkmqrvqktpuluvuknuxpmm (master)` + // - If there are 2+ branches: `vyvqwlmsvnlkmqrvqktpuluvuknuxpmm (master, jj-diffs)` + // + // Always using the long id makes it easy to share it with others, which would not be the + // case for shorter ones: they could have a local change that renders it ambiguous. + let template = r#"separate(" ", change_id, surround("(", ")", branches.join(", ")))"#; + + let out = Command::new("jj") + .arg("--repository") + .arg(jj_root_dir) + .args([ + "log", + "--color", + "never", + "--revisions", + "@", // Only display the current revision + "--no-graph", + "--template", + template, + ]) + .output()?; + + if !out.status.success() { + anyhow::bail!("jj log command executed but failed"); + } + + let out = String::from_utf8(out.stdout)?; + + let rev = out + .lines() + .next() + .context("should always find at least one line")?; + + Ok(Arc::new(ArcSwap::from_pointee(rev.into()))) + } +} + +// Move up until we find the repository's root +fn find_jj_root(file: &Path) -> Result<&Path> { + file.ancestors() + .find(|p| p.join(".jj").exists()) + .context("no .jj dir found in parents") +} diff --git a/helix-vcs/src/lib.rs b/helix-vcs/src/lib.rs index 63487fbcde6c7..62402a08c3358 100644 --- a/helix-vcs/src/lib.rs +++ b/helix-vcs/src/lib.rs @@ -10,6 +10,9 @@ pub use Dummy as Git; #[cfg(feature = "git")] mod git; +#[cfg(feature = "jujutsu")] +mod jujutsu; + mod diff; pub use diff::{DiffHandle, Hunk}; @@ -72,7 +75,14 @@ impl Default for DiffProviderRegistry { // currently only git is supported // TODO make this configurable when more providers are added let git: Box = Box::new(Git); - let providers = vec![git]; + #[cfg(feature = "jujutsu")] + let jj: Box = Box::new(jujutsu::Jujutsu); + + let providers = vec![ + git, + #[cfg(feature = "jujutsu")] + jj, + ]; DiffProviderRegistry { providers } } }