feat: gts builder file paths

Signed-off-by: devjow <me@devjow.com>

Author: devjow

gts-cli/src/gen_instances/mod.rs

@@ -121,7 +121,8 @@ fn check_duplicate_output_paths(
 
     for inst in instances {
         let composed = format!("{}{}", inst.attrs.schema_id, inst.attrs.instance_segment);
-        let file_rel = format!("{}/{}.instance.json", inst.attrs.dir_path, composed);
+        let file_rel =
+            std::path::Path::new(&inst.attrs.dir_path).join(format!("{composed}.instance.json"));
         let raw_path = if let Some(od) = output {
             Path::new(od).join(&file_rel)
         } else {

gts-cli/src/gen_instances/writer.rs

@@ -24,7 +24,8 @@ pub fn generate_single_instance(
     sandbox_root: &Path,
 ) -> Result<String> {
     let composed = format!("{}{}", inst.attrs.schema_id, inst.attrs.instance_segment);
-    let file_rel = format!("{}/{}.instance.json", inst.attrs.dir_path, composed);
+    let file_rel =
+        std::path::Path::new(&inst.attrs.dir_path).join(format!("{composed}.instance.json"));
 
     let raw_output_path = if let Some(od) = output {
         Path::new(od).join(&file_rel)

gts-cli/tests/gen_instances_tests.rs

@@ -372,7 +372,14 @@ fn gts_ignore_directive_skips_file() {
 
 #[test]
 fn missing_source_path_errors() {
-    let err = run("/nonexistent/path/absolutely/not/here", None, &[]).unwrap_err();
+    // Use a path guaranteed not to exist on any platform by constructing it
+    // inside a TempDir that is immediately dropped (and thus deleted).
+    let nonexistent = {
+        let tmp = TempDir::new().unwrap();
+        tmp.path().join("no_such_subdir_xyz")
+        // tmp is dropped here — the parent dir is deleted
+    };
+    let err = run(nonexistent.to_str().unwrap(), None, &[]).unwrap_err();
     assert!(err.to_string().contains("does not exist"), "Got: {err}");
 }