Improves sourcemap path handling with pathdiff (#1217)

CHANGELOG.md

@@ -38,6 +38,7 @@ Making a new release? Simply add the new header with the version and date undern
 * Fixed a bug where MacOS paths weren't being handled correctly. ([#1201])
 * Fixed a bug where the notification timeout thread would fail to cancel on unmount ([#1211])
 * Added a "Forget" option to the sync reminder notification to avoid being reminded for that place in the future ([#1215])
+* Improves relative path calculation for sourcemap generation to avoid issues with Windows UNC paths. ([#1217])
 
 [#1176]: https://github.com/rojo-rbx/rojo/pull/1176
 [#1179]: https://github.com/rojo-rbx/rojo/pull/1179
@@ -46,6 +47,7 @@ Making a new release? Simply add the new header with the version and date undern
 [#1201]: https://github.com/rojo-rbx/rojo/pull/1201
 [#1211]: https://github.com/rojo-rbx/rojo/pull/1211
 [#1215]: https://github.com/rojo-rbx/rojo/pull/1215
+[#1217]: https://github.com/rojo-rbx/rojo/pull/1217
 
 ## [7.7.0-rc.1] (November 27th, 2025)
 

CONTRIBUTING.md

@@ -14,6 +14,7 @@ Code contributions are welcome for features and bugs that have been reported in
 You'll want these tools to work on Rojo:
 
 * Latest stable Rust compiler
+  * Rustfmt and Clippy are used for code formatting and linting.
 * Latest stable [Rojo](https://github.com/rojo-rbx/rojo)
 * [Rokit](https://github.com/rojo-rbx/rokit)
 * [Luau Language Server](https://github.com/JohnnyMorganz/luau-lsp) (Only needed if working on the Studio plugin.)

Cargo.lock

@@ -1520,6 +1520,12 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
 
+[[package]]
+name = "pathdiff"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df94ce210e5bc13cb6651479fa48d14f601d9858cfe0467f43ae157023b938d3"
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -2068,6 +2074,7 @@ dependencies = [
  "num_cpus",
  "opener",
  "paste",
+ "pathdiff",
  "pretty_assertions",
  "profiling",
  "rayon",

Cargo.toml

@@ -100,6 +100,7 @@ clap = { version = "3.2.25", features = ["derive"] }
 profiling = "1.0.15"
 yaml-rust2 = "0.10.3"
 data-encoding = "2.8.0"
+pathdiff = "0.2.3"
 
 blake3 = "1.5.0"
 float-cmp = "0.9.0"
@@ -124,7 +125,7 @@ semver = "1.0.22"
 rojo-insta-ext = { path = "crates/rojo-insta-ext" }
 
 criterion = "0.3.6"
-insta = { version = "1.36.1", features = ["redactions", "yaml"] }
+insta = { version = "1.36.1", features = ["redactions", "yaml", "json"] }
 paste = "1.0.14"
 pretty_assertions = "1.4.0"
 serde_yaml = "0.8.26"

src/cli/snapshots/librojo__cli__sourcemap__test__maps_absolute_paths.snap

@@ -0,0 +1,35 @@
+---
+source: src/cli/sourcemap.rs
+expression: sourcemap_contents
+---
+{
+  "name": "default",
+  "className": "DataModel",
+  "filePaths": "[...1 path omitted...]",
+  "children": [
+    {
+      "name": "ReplicatedStorage",
+      "className": "ReplicatedStorage",
+      "children": [
+        {
+          "name": "Project",
+          "className": "ModuleScript",
+          "filePaths": "[...1 path omitted...]",
+          "children": [
+            {
+              "name": "Module",
+              "className": "Folder",
+              "children": [
+                {
+                  "name": "module",
+                  "className": "ModuleScript",
+                  "filePaths": "[...1 path omitted...]"
+                }
+              ]
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

src/cli/snapshots/librojo__cli__sourcemap__test__maps_relative_paths.snap

@@ -0,0 +1,41 @@
+---
+source: src/cli/sourcemap.rs
+expression: sourcemap_contents
+---
+{
+  "name": "default",
+  "className": "DataModel",
+  "filePaths": [
+    "default.project.json"
+  ],
+  "children": [
+    {
+      "name": "ReplicatedStorage",
+      "className": "ReplicatedStorage",
+      "children": [
+        {
+          "name": "Project",
+          "className": "ModuleScript",
+          "filePaths": [
+            "src/init.luau"
+          ],
+          "children": [
+            {
+              "name": "Module",
+              "className": "Folder",
+              "children": [
+                {
+                  "name": "module",
+                  "className": "ModuleScript",
+                  "filePaths": [
+                    "../module/module.luau"
+                  ]
+                }
+              ]
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

src/cli/sourcemap.rs

@@ -10,7 +10,7 @@ use fs_err::File;
 use memofs::Vfs;
 use rayon::prelude::*;
 use rbx_dom_weak::{types::Ref, Ustr};
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use tokio::runtime::Runtime;
 
 use crate::{
@@ -24,19 +24,20 @@ const PATH_STRIP_FAILED_ERR: &str = "Failed to create relative paths for project
 const ABSOLUTE_PATH_FAILED_ERR: &str = "Failed to turn relative path into absolute path!";
 
 /// Representation of a node in the generated sourcemap tree.
-#[derive(Serialize)]
+#[derive(Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 struct SourcemapNode<'a> {
     name: &'a str,
     class_name: Ustr,
 
     #[serde(
+        default,
         skip_serializing_if = "Vec::is_empty",
         serialize_with = "crate::path_serializer::serialize_vec_absolute"
     )]
     file_paths: Vec<Cow<'a, Path>>,
 
-    #[serde(skip_serializing_if = "Vec::is_empty")]
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
     children: Vec<SourcemapNode<'a>>,
 }
 
@@ -70,12 +71,13 @@ pub struct SourcemapCommand {
 
 impl SourcemapCommand {
     pub fn run(self) -> anyhow::Result<()> {
-        let project_path = resolve_path(&self.project);
+        let project_path = fs_err::canonicalize(resolve_path(&self.project))?;
 
-        log::trace!("Constructing in-memory filesystem");
+        log::trace!("Constructing filesystem with StdBackend");
         let vfs = Vfs::new_default();
         vfs.set_watch_enabled(self.watch);
 
+        log::trace!("Setting up session for sourcemap generation");
         let session = ServeSession::new(vfs, project_path)?;
         let mut cursor = session.message_queue().cursor();
 
@@ -87,14 +89,17 @@ impl SourcemapCommand {
 
         // Pre-build a rayon threadpool with a low number of threads to avoid
         // dynamic creation overhead on systems with a high number of cpus.
+        log::trace!("Setting rayon global threadpool");
         rayon::ThreadPoolBuilder::new()
             .num_threads(num_cpus::get().min(6))
             .build_global()
-            .unwrap();
+            .ok();
 
+        log::trace!("Writing initial sourcemap");
         write_sourcemap(&session, self.output.as_deref(), filter, self.absolute)?;
 
         if self.watch {
+            log::trace!("Setting up runtime for watch mode");
             let rt = Runtime::new().unwrap();
 
             loop {
@@ -208,7 +213,7 @@ fn recurse_create_node<'a>(
     } else {
         for val in file_paths {
             output_file_paths.push(Cow::from(
-                val.strip_prefix(project_dir).expect(PATH_STRIP_FAILED_ERR),
+                pathdiff::diff_paths(val, project_dir).expect(PATH_STRIP_FAILED_ERR),
             ));
         }
     };
@@ -250,3 +255,80 @@ fn write_sourcemap(
 
     Ok(())
 }
+
+#[cfg(test)]
+mod test {
+    use crate::cli::sourcemap::SourcemapNode;
+    use crate::cli::SourcemapCommand;
+    use insta::internals::Content;
+    use std::path::Path;
+
+    #[test]
+    fn maps_relative_paths() {
+        let sourcemap_dir = tempfile::tempdir().unwrap();
+        let sourcemap_output = sourcemap_dir.path().join("sourcemap.json");
+        let project_path = fs_err::canonicalize(
+            Path::new(env!("CARGO_MANIFEST_DIR"))
+                .join("test-projects")
+                .join("relative_paths")
+                .join("project"),
+        )
+        .unwrap();
+        let sourcemap_command = SourcemapCommand {
+            project: project_path,
+            output: Some(sourcemap_output.clone()),
+            include_non_scripts: false,
+            watch: false,
+            absolute: false,
+        };
+        assert!(sourcemap_command.run().is_ok());
+
+        let raw_sourcemap_contents = fs_err::read_to_string(sourcemap_output.as_path()).unwrap();
+        let sourcemap_contents =
+            serde_json::from_str::<SourcemapNode>(&raw_sourcemap_contents).unwrap();
+        insta::assert_json_snapshot!(sourcemap_contents);
+    }
+
+    #[test]
+    fn maps_absolute_paths() {
+        let sourcemap_dir = tempfile::tempdir().unwrap();
+        let sourcemap_output = sourcemap_dir.path().join("sourcemap.json");
+        let project_path = fs_err::canonicalize(
+            Path::new(env!("CARGO_MANIFEST_DIR"))
+                .join("test-projects")
+                .join("relative_paths")
+                .join("project"),
+        )
+        .unwrap();
+        let sourcemap_command = SourcemapCommand {
+            project: project_path,
+            output: Some(sourcemap_output.clone()),
+            include_non_scripts: false,
+            watch: false,
+            absolute: true,
+        };
+        assert!(sourcemap_command.run().is_ok());
+
+        let raw_sourcemap_contents = fs_err::read_to_string(sourcemap_output.as_path()).unwrap();
+        let sourcemap_contents =
+            serde_json::from_str::<SourcemapNode>(&raw_sourcemap_contents).unwrap();
+        insta::assert_json_snapshot!(sourcemap_contents, {
+            ".**.filePaths" => insta::dynamic_redaction(|mut value, _path| {
+                let mut paths_count = 0;
+
+                match value {
+                    Content::Seq(ref mut vec) => {
+                        for path in vec.iter().map(|i| i.as_str().unwrap()) {
+                            assert_eq!(fs_err::canonicalize(path).is_ok(), true, "path was not valid");
+                            assert_eq!(Path::new(path).is_absolute(), true, "path was not absolute");
+
+                            paths_count += 1;
+                        }
+                    }
+                    _ => panic!("Expected filePaths to be a sequence"),
+                }
+                format!("[...{} path{} omitted...]", paths_count, if paths_count != 1 { "s" } else { "" } )
+            })
+        });
+    }
+}

test-projects/relative_paths/default.project.json

@@ -0,0 +1,14 @@
+{
+  "name": "default",
+  "tree": {
+    "$className": "DataModel",
+    "ReplicatedStorage": {
+      "Project": {
+        "$path": "project/src",
+        "Module": {
+          "$path": "module"
+        }
+      }
+    }
+  }
+}

test-projects/relative_paths/module/module.luau

@@ -0,0 +1 @@
+return nil

test-projects/relative_paths/project/default.project.json

@@ -0,0 +1,14 @@
+{
+  "name": "default",
+  "tree": {
+    "$className": "DataModel",
+    "ReplicatedStorage": {
+      "Project": {
+        "$path": "src/",
+        "Module": {
+          "$path": "../module"
+        }
+      }
+    }
+  }
+}

test-projects/relative_paths/project/src/init.luau

@@ -0,0 +1 @@
+return nil