add non-linux check

src/lib.rs

@@ -164,12 +164,20 @@ impl Pty {
         }
 
         // set the cgroup if specified
+        #[cfg(target_os = "linux")]
         if let Some(cgroup_path) = &opts.cgroup_path {
           let pid = libc::getpid();
           let cgroup_path = format!("{}/cgroup.procs", cgroup_path);
           let mut cgroup_file = File::create(cgroup_path)?;
           cgroup_file.write_all(format!("{}", pid).as_bytes())?;
         }
+        #[cfg(not(target_os = "linux"))]
+        if opts.cgroup_path.is_some() {
+          return Err(Error::new(
+            ErrorKind::Other,
+            "cgroup_path is only supported on Linux",
+          ));
+        }
 
         // become the controlling tty for the program
         let err = libc::ioctl(raw_user_fd, libc::TIOCSCTTY.into(), 0);

tests/index.test.ts

@@ -11,6 +11,7 @@ const procSelfFd = '/proc/self/fd/';
 const IS_DARWIN = process.platform === 'darwin';
 
 const testSkipOnDarwin = IS_DARWIN ? test.skip : test;
+const testOnlyOnDarwin = IS_DARWIN ? test : test.skip;
 
 type FdRecord = Record<string, string>;
 function getOpenFds(): FdRecord {
@@ -419,10 +420,8 @@ describe(
 
 describe('cgroup opts', () => {
   testSkipOnDarwin('basic cgroup', async () => {
-    // create a new cgroup
+    // create a new cgroup with the right permissions
     await exec("sudo cgcreate -g 'cpu:/test.slice'")
-
-    // Set permissions for the test user
     await exec("sudo chown -R $(id -u):$(id -g) /sys/fs/cgroup/cpu/test.slice")
 
     return new Promise<void>((done) => {
@@ -447,6 +446,20 @@ describe('cgroup opts', () => {
       });
     });
   });
+
+  testOnlyOnDarwin('cgroup is not supported on darwin', () => {
+    expect(() => {
+      new Pty({
+        command: '/bin/cat',
+        args: ['/proc/self/cgroup'],
+        cgroupPath: '/sys/fs/cgroup/cpu/test.slice',
+        onExit: (err, exitCode) => {
+          expect(err).toBeNull();
+          expect(exitCode).toBe(0);
+        },
+      })
+    }).toThrowError();
+  });
 });
 
 describe('setCloseOnExec', () => {