fix(turborepo): Use which crate to resolve yarn binary (#5001)

### Description

Fixes #4940 by using `which` crate to resolve yarn binary. That way we
use the correct extension, i.e. `yarn.cmd` on Windows.


### Testing Instructions
Tested manually on Windows. Will add more integration tests

---------

Co-authored-by: --global <Nicholas Yang>

Cargo.toml

@@ -197,3 +197,4 @@ tracing-subscriber = "0.3.16"
 url = "2.2.2"
 urlencoding = "2.1.2"
 webbrowser = "0.8.7"
+which = "4.4.0"

crates/turborepo-lib/Cargo.toml

@@ -93,6 +93,7 @@ turbo-updater = { workspace = true }
 turbopath = { workspace = true }
 turborepo-api-client = { workspace = true }
 webbrowser = { workspace = true }
+which = { workspace = true }
 
 
 [target.'cfg(target_os = "windows")'.dependencies]

crates/turborepo-lib/src/package_manager/yarn.rs

@@ -4,6 +4,7 @@ use anyhow::{anyhow, Context, Result};
 use node_semver::{Range, Version};
 use serde::Deserialize;
 use turbopath::{AbsoluteSystemPathBuf, RelativeSystemPathBuf};
+use which::which;
 
 use crate::package_manager::PackageManager;
 
@@ -42,7 +43,8 @@ impl<'a> YarnDetector<'a> {
             return Ok(version.clone());
         }
 
-        let output = Command::new("yarn")
+        let yarn_binary = which("yarn")?;
+        let output = Command::new(yarn_binary)
             .arg("--version")
             .current_dir(&self.repo_root)
             .output()?;

crates/turborepo-scm/Cargo.toml

@@ -12,6 +12,7 @@ dunce = { workspace = true }
 git2 = { version = "0.16.1", default-features = false }
 thiserror = { workspace = true }
 turbopath = { workspace = true }
+which = { workspace = true }
 
 [dev-dependencies]
 tempfile = { workspace = true }

crates/turborepo-scm/src/git.rs

@@ -5,6 +5,7 @@ use std::{
 use turbopath::{
     AbsoluteSystemPath, AbsoluteSystemPathBuf, AnchoredSystemPathBuf, RelativeUnixPath,
 };
+use which::which;
 
 use crate::Error;
 
@@ -76,7 +77,8 @@ fn execute_git_command(
     args: &[&str],
     pathspec: &str,
 ) -> Result<Vec<u8>, Error> {
-    let mut command = Command::new("git");
+    let git_binary = which("git")?;
+    let mut command = Command::new(git_binary);
     command.args(args).current_dir(git_root);
 
     add_pathspec(&mut command, pathspec);
@@ -156,7 +158,8 @@ pub fn previous_content(
         file_path.as_path().try_into()?
     };
 
-    let mut command = Command::new("git");
+    let git_binary = which("git")?;
+    let mut command = Command::new(git_binary);
     let command = command
         .arg("show")
         .arg(format!(
@@ -190,6 +193,7 @@ mod tests {
     use git2::{Oid, Repository};
     use tempfile::TempDir;
     use turbopath::{PathError, PathValidationError};
+    use which::which;
 
     use super::previous_content;
     use crate::{git::changed_files, Error};
@@ -253,7 +257,9 @@ mod tests {
     #[test]
     fn test_shallow_clone() -> Result<(), Error> {
         let tmp_dir = tempfile::tempdir()?;
-        let output = Command::new("git")
+
+        let git_binary = which("git")?;
+        let output = Command::new(git_binary)
             .args(&[
                 "clone",
                 "--depth",

crates/turborepo-scm/src/lib.rs

@@ -19,4 +19,6 @@ pub enum Error {
     Io(#[from] std::io::Error, #[backtrace] backtrace::Backtrace),
     #[error("path error: {0}")]
     Path(#[from] PathError, #[backtrace] backtrace::Backtrace),
+    #[error("could not find git binary")]
+    GitBinaryNotFound(#[from] which::Error),
 }

turborepo-tests/integration/tests/package_manager.t

@@ -36,3 +36,48 @@ Set package manager to pnpm in package.json
 Run test run
   $ ${TURBO} run build --__test-run | jq .package_manager
   "pnpm"
+
+Clear package manager field in package.json
+  $ jq 'del(.packageManager)' package.json > package.json.tmp && mv package.json.tmp package.json
+
+Delete package-lock.json
+  $ rm package-lock.json
+
+Use yarn 1.22.19
+  $ corepack prepare yarn@1.22.19 --activate
+  Preparing yarn@1.22.19 for immediate activation...
+
+Create yarn.lock
+  $ touch yarn.lock
+
+Run test run
+  $ ${TURBO} run build --__test-run | jq .package_manager
+  "yarn"
+
+Use yarn 3.5.1
+  $ corepack prepare yarn@3.5.1 --activate
+  Preparing yarn@3.5.1 for immediate activation...
+
+Run test run
+  $ ${TURBO} run build --__test-run | jq .package_manager
+  "berry"
+
+Delete yarn.lock
+  $ rm yarn.lock
+
+Create pnpm-lock.yaml
+  $ touch pnpm-lock.yaml
+
+Run test run
+  $ ${TURBO} run build --__test-run | jq .package_manager
+  "pnpm"
+
+Delete pnpm-lock.yaml
+  $ rm pnpm-lock.yaml
+
+Create package-lock.json
+  $ touch package-lock.json
+
+Run test run
+  $ ${TURBO} run build --__test-run | jq .package_manager
+  "npm"