1 use std::{path::Path, process::Command};
3 /// Finds the remote for rust-lang/rust.
4 /// For example for these remotes it will return `upstream`.
6 /// origin https://github.com/Nilstrieb/rust.git (fetch)
7 /// origin https://github.com/Nilstrieb/rust.git (push)
8 /// upstream https://github.com/rust-lang/rust (fetch)
9 /// upstream https://github.com/rust-lang/rust (push)
11 pub fn get_rust_lang_rust_remote(git_dir: Option<&Path>) -> Result<String, String> {
12 let mut git = Command::new("git");
13 if let Some(git_dir) = git_dir {
14 git.current_dir(git_dir);
16 git.args(["config", "--local", "--get-regex", "remote\\..*\\.url"]);
18 let output = git.output().map_err(|err| format!("{err:?}"))?;
19 if !output.status.success() {
20 return Err("failed to execute git config command".to_owned());
23 let stdout = String::from_utf8(output.stdout).map_err(|err| format!("{err:?}"))?;
25 let rust_lang_remote = stdout
27 .find(|remote| remote.contains("rust-lang"))
28 .ok_or_else(|| "rust-lang/rust remote not found".to_owned())?;
31 rust_lang_remote.split('.').nth(1).ok_or_else(|| "remote name not found".to_owned())?;
32 Ok(remote_name.into())
35 pub fn rev_exists(rev: &str, git_dir: Option<&Path>) -> Result<bool, String> {
36 let mut git = Command::new("git");
37 if let Some(git_dir) = git_dir {
38 git.current_dir(git_dir);
40 git.args(["rev-parse", rev]);
41 let output = git.output().map_err(|err| format!("{err:?}"))?;
43 match output.status.code() {
45 Some(128) => Ok(false),
48 "git didn't exit properly: {}",
49 String::from_utf8(output.stderr).map_err(|err| format!("{err:?}"))?
54 "git command exited with status code: {code}: {}",
55 String::from_utf8(output.stderr).map_err(|err| format!("{err:?}"))?
61 /// Returns the master branch from which we can take diffs to see changes.
62 /// This will usually be rust-lang/rust master, but sometimes this might not exist.
63 /// This could be because the user is updating their forked master branch using the GitHub UI
64 /// and therefore doesn't need an upstream master branch checked out.
65 /// We will then fall back to origin/master in the hope that at least this exists.
66 pub fn updated_master_branch(git_dir: Option<&Path>) -> Result<String, String> {
67 let upstream_remote = get_rust_lang_rust_remote(git_dir)?;
68 let upstream_master = format!("{upstream_remote}/master");
69 if rev_exists(&upstream_master, git_dir)? {
70 return Ok(upstream_master);
73 // We could implement smarter logic here in the future.
74 Ok("origin/master".into())